JP3659935B2 - Rectifier, rectifier tube and flow meter provided with the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rectifier, and a rectifier tube and a flow meter including the rectifier.
[0002]
[Prior art]
Rectifiers that rectify the fluid in the flow tube are used in various flow meters for measuring the fluid to be measured in the flow tube to achieve a more reliable flow velocity or flow distribution in the flow tube. Further, the fluid may be rectified by providing as a rectifying tube in the flow tube.
[0003]
Conventionally, rectifiers that use honeycombs, perforated plates, etc. are well known, but those with many holes have low pressure loss but low rectification effect, while those with few holes depend on their shape. Can expect a rectifying effect, but has a large pressure loss.
[0004]
For this reason, in the conventional rectifier, in order to obtain the rectification effect, it is necessary to lengthen the piping. In addition, when applying a rectifier upstream of the flow meter measurement section, it is necessary to lengthen the piping between the rectifier and the measurement section, or to separately determine the pressure loss due to the rectifier, Incurred high costs.
[0005]
[Problems to be solved by the invention]
The present invention has been made in view of the actual situation as described above, and has a low pressure loss and no need to lengthen the pipe, so that the flow of the fluid is stable, that is, the average flow velocity or average of the flow pipe at the representative position in the flow pipe. It is an object of the present invention to provide a rectifier and a rectifier tube including the rectifier that can be adjusted to a flow having a flow rate.
[0006]
The present invention eliminates the need for lengthening the piping, and does not require separate calculation of the pressure loss due to itself when measuring the flow velocity or flow rate, and allows the fluid to flow stably, i.e., the average flow velocity or average of the flow tube at representative positions in the flow tube. Another object is to provide a flowmeter using a rectifier that can be adjusted to a flow having a flow rate.
[0007]
[Means for Solving the Problems]
The present invention solves the above-mentioned problems by the following technical means.
The first technical means is a rectifier for rectifying the fluid flowing in the flow tube arranged in the flow tube, and among the fluid flowing from the upstream side, the fluid located at the center of the flow tube is the flow tube An obstacle part for constricting to the inner peripheral wall side, the obstacle part having a circular cross section concentric with the flow tube, and a column body part downstream of the obstacle part, and concentric with the obstacle part And a columnar intermediate portion having a cross section smaller than the radial cross section of the obstruction portion, and a column body portion downstream of the intermediate portion, the diameter being concentric with the obstruction portion and matching the inner diameter of the flow tube A plurality of holes for allowing the fluid flowing on the side surface of the intermediate portion to flow out to the downstream side. The plurality of holes of the holes have a part or all of the inflow portion as viewed from the front of the flow. Is obtained is characterized in that a diameter of the harm portion at a position corresponding to a radially outward of the intermediate portion.
[0008]
According to a second technical means, in the first technical means, the plurality of holes are a plurality of circular holes arranged evenly on a concentric circle of the outflow portion.
[0009]
The third technical means is the first or second technical means, wherein the outflow portion is sandwiched between the upstream flow tube and the downstream flow tube integrally on the downstream side of the outflow portion. A cylindrical space having the same diameter as that of the downstream side flow pipe is formed.
[0010]
A fourth technical means is a rectifier tube comprising the rectifier according to any one of the first to third aspects, and a rectifier main body having a diameter matching the outflow portion of the rectifier and having the rectifier disposed in a flow path. The rectifier pipe rectifies the fluid flowing from the upstream flow pipe having an inner diameter smaller than the inner diameter of the flow path of the rectifier pipe body, which is disposed on the upstream side of the rectifier pipe, by the rectifier. It is characterized by being arranged in such a manner.
[0011]
According to a fifth technical means, in the flow meter, the rectifier according to any one of the first to third is arranged upstream of the flow velocity or flow rate measuring unit.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
1A and 1B are diagrams illustrating a configuration example of a rectifier according to an embodiment of the present invention. FIG. 1A is a front view of the rectifier as viewed from the fluid outflow side, and FIG. 1B is a cross-sectional view in the flow direction of the rectifier. FIG. 1C is a front view of the rectifier as seen from the fluid inflow side.
The rectifier 10 according to one embodiment of the present invention should be disposed in the flow tube for the purpose of rectifying the fluid flowing in the flow tube, and in particular, the upstream pipe diameter is set to the downstream pipe diameter. On the other hand, it is useful when it is small. The rectifier 10 is characterized in that an obstacle part 11, an intermediate part 12, and an outflow part 13 which will be described later are integrally formed. In the manufacture thereof, any or all of the parts 11, 12, and 13 are separately molded. It may be manufactured by bonding with an adhesive or the like, or may be manufactured by integrally molding from the beginning and performing a cutting process. Further, the material of the rectifier 10 is not particularly limited, but a metal, a resin, or the like may be selected in accordance with the use such as the characteristics of the fluid and the set durability.
[0013]
The obstruction part 11 has a diameter smaller than the diameter of the flow tube (flow tube diameter at the rectifier installation position) and has a circular cross section concentric with the flow tube. In the following description, the obstacle portion 11 is exemplified as a cylindrical body (including a disk shape) having a plane concentric with the flow tube and perpendicular to the flow. However, the obstacle 11 does not have to have a plane perpendicular to the flow as shown later. With this shape, the obstacle 11 can restrict the fluid located in the center of the flow tube from the upstream side (in the direction of the arrow in the figure) to the inner peripheral wall.
[0014]
Further, the intermediate portion 12 is a columnar body portion downstream from the obstacle portion 11, and is a columnar body that is concentric with the obstacle portion 11 (the center is the same) and has a cross section smaller than the radial section of the obstacle portion 11. There is no. The cross section in the radial direction of the obstacle portion 11 is a cross section perpendicular to the flow direction in the obstacle portion 11, and the cross section of the intermediate portion 12 is at least smaller than the radial cross section at the position having the maximum diameter of the obstacle portion 11. The shape of the intermediate portion 12 may be prismatic or cylindrical, but particularly in the case of a prismatic shape, it should be designed in consideration of the arrangement of the holes 14 described later. In the following description, the intermediate portion 12 is illustrated as having a cylindrical body having a diameter smaller than that of the obstacle portion 11.
[0015]
The outflow portion 13 is a columnar body portion that follows the downstream side of the intermediate portion 12, and forms a cylindrical body that is concentric with the obstacle portion 11 and has a diameter that matches the inner diameter of the flow tube. Here, the diameter that matches the inner diameter of the flow tube refers to a diameter that can be connected without a gap (so that fluid does not flow out from other than holes 14 described later). It is about the same diameter. In addition, the structure in the case of continuing two flow tubes with this rectifier 10 is later mentioned with reference to FIG. The outflow part 13 is further restricted by the obstacle part 11 to the inner peripheral wall side of the flow tube, and has a plurality of holes (through holes) 14 for allowing the fluid flowing through the side surface of the intermediate part 12 to flow out downstream. The plurality of holes 14 have a space (corresponding to a portion indicated by 14a) for allowing fluid to flow out at least at a position within the diameter of the obstacle 11 and outside the diameter of the intermediate portion 12 when viewed from the front of the flow. Shall. In other words, it is assumed that a plurality of holes in each hole 14 have a part (for example, a part indicated by 14 a) or all of the inflow part at the position of the outflow part 13. In short, it is only necessary that the fluid flows out from the shadowed portion by the obstacle 11. This is intended to reduce the diameter of the intermediate portion 12 and increase the total cross-sectional area of the hole 14 as much as possible. In FIG. 1, the diameter / height of the obstacle part 11, the intermediate part 12, and the outflow part 13 are respectively R ₁ / L ₁ , R ₂ / L ₂ , R ₃ / L ₃ , and the diameter of the through hole is R It is represented by ₄ -R _5. The diameter R ₄ -R ₅ of the through hole 14 may be determined by its height L ₃ .
[0016]
Considering the rectifying effect, the plurality of holes 14 are preferably a plurality of circular holes arranged evenly on the concentric circumference of the outflow portion 13 as shown in FIG. In FIG. 1, as an example of this arrangement, the circular holes 14 are evenly arranged in 45 degree steps. Also, it is desirable to increase the number of holes 14 in order to reduce pressure loss. Each hole 14 is not limited to a hole having a cross-section as shown in FIG. 1 and its arrangement, but may be selected if there is an optimum one by experimenting with various shapes and arrangements such as a prismatic hole. That's fine.
[0017]
FIG. 2 is a diagram showing another configuration example of the rectifier according to the embodiment of the present invention, and FIGS. 2A and 2B are front views of different rectifiers as seen from the fluid outflow side. However, in FIG. 2, a sectional view in the flow direction as shown in FIG. 1B and a front view as seen from the fluid inflow side as shown in FIG. 1C are omitted. The rectifier according to the embodiment described in FIG. 1 may include holes 14 ₁ and 14 ₂ having different cross-sectional shapes as shown in FIG. 2 (A), and further, as shown in FIG. 2 (B). A large number of holes 14 ₃ , 14 ₄ may be provided. In FIG. 2B, the hole 14 ₃ is formed at a position where the cross section corresponds to the inside of the obstacle portion 11, and the hole 14 ₄ is formed at a position where the cross section corresponds to outside the diameter of the obstacle portion 11. An example is shown. In addition, holes having shapes as shown in FIG. 2 and holes having other shapes may be applied to the rectifiers of the embodiments described below, and their arrangement is also point-symmetric with respect to the cross-sectional center of the rectifier. If there is, the rectification effect can be expected.
[0018]
3A and 3B are diagrams showing a configuration example of a rectifier according to another embodiment of the present invention. FIG. 3A is a front view of the rectifier as seen from the fluid outflow side, and FIG. 3B is a cross-sectional view in the flow direction of the rectifier. FIG. 3C is a front view of the rectifier as seen from the fluid inflow side.
The rectifier 10 which concerns on other embodiment of this invention shall form the cylindrical space 15 in the outflow part 13 in the downstream of the outflow part 13 in the outflow part 13. As shown in FIG. The cylindrical space 15 is a space provided so as to be sandwiched between the upstream flow tube and the downstream flow tube, and has the same diameter as the downstream flow tube. The downstream side of the outflow portion 13 cut by the cylindrical space 15 can be connected integrally with the downstream flow tube. At this time, in view of the rectifying effect, the boundary of the space (portion where the fluid flows out) corresponding to the outermost wall side of the plurality of holes 14 is within the diameter range of the cylindrical space 15 when viewed from the front of the flow. Must be in. FIG. 3 shows an example in which the above-described outer boundaries of the plurality of holes 14 are made to coincide with the diameter of the cylindrical space 15. In addition, since the donut-shaped part made of the cylindrical space 15 can be substituted by a spacer or the like, the form described with reference to FIG. 1 can also be adopted. Further, in FIG. 3, L ₄ indicates the height of the cylindrical space 15, and the height of the hole 14 in this example is L ₃ -L ₄ .
[0019]
FIG. 4 is a diagram showing a configuration example of a rectifier according to another embodiment of the present invention, and is a cross-sectional view in the flow direction of the rectifier.
As another embodiment of the present invention, the corners of the rectifier 10 may be cut and rounded. 4 shows an example in which the side surface portion 11a of the obstacle portion 11 is rounded, and the boundary portion 12a of the intermediate portion 12 with the outflow portion 13 and the boundary portion 12b with the obstacle portion 11 are rounded. In addition, although the inflow port in the porous 14 may be rounded, it is necessary to make the flow well arranged in view of the balance with the height of the hole 14.
[0020]
FIG. 5 is a diagram showing a configuration example of a flow meter provided with a rectifier according to an embodiment of the present invention, and shows a configuration example in which the rectifier of FIG. 4 is arranged upstream of a detection sensor of a thermal mass flow meter. FIG.
In the flow meter according to an embodiment of the present invention, the rectifier according to each embodiment described above is arranged upstream of the flow velocity or flow rate measurement unit so as to derive an appropriate measurement result. In FIG. 5, the thermal mass flow meter 1 is described as an example of the flow meter, but it is needless to mention that it can be applied to other types of flow meters.
[0021]
The thermal mass flowmeter 1 according to this configuration example includes a temperature sensor (temperature sensor) 25 disposed in the flow path 20 ′ of the flow tube 20 and a heating temperature sensor 26 disposed downstream thereof. It is assumed that the rectifier 10 is provided on the upstream side of the flow rate measurement unit having In addition, the example which employ | adopted the rectifier demonstrated with reference to FIG. 4 is shown here. The rectifier 10 is joined so that a tube wall is integrated between a flow tube 22 and a flow tube 23 embedded in the flow tube 20 with the same inner diameter. The fluid that has flowed in is pushed to the inner wall side of the flow tube 22 by the obstruction part 11 and flows out from the through hole 14 of the outflow part 13. The flow adjusted by the rectifier 10 is measured by the heating temperature sensor 26 based on the temperature of the temperature sensor 25, and the mass flow rate can be calculated. In other words, the rectifier 10 makes it possible to arrange the fluid into a stable flow, that is, a flow having an average flow velocity or average flow rate of the flow tube 20 at a representative position in the flow tube 20. When the diameter of the flow tube 21 on the upstream side of the rectifier 10 is smaller than the diameter of the flow tube 20 on the downstream side, as shown in the figure, the diameter R _{1 of} a plane circle perpendicular to the flow of the obstacle portion 11 is shown. Is preferably set to be substantially the same as D or larger than D, where D is the diameter of the upstream pipe (flow pipe 21) of the rectifier 10.
[0022]
The heating temperature sensor 26 has functions of a temperature sensor and a heating sensor, and performs flow rate measurement based on the temperature detected by the temperature sensor 25. That is, the flow rate measurement unit of the thermal mass flow meter 1 heats the heating temperature sensor 26 so that the temperature difference between the temperature sensor 25 and the heating temperature sensor 26 is constant (for example, + 30 ° C.) Flow) to measure the mass flow rate. When the fluid to be measured flows, the heating temperature sensor 26 is cooled. Therefore, in order to control the temperature difference with the temperature sensor 25 to a constant level, a further current flows. At this time, the current flowing to the heating temperature sensor 26 The mass flow rate is detected using the fact that is proportional to the mass flow rate.
[0023]
In addition, as shown in FIG. 5, a mesh-like filter, a porous plate, or the like 24 may be disposed on the upstream side and / or the downstream side of the rectifier 10. This filter or the like may be for obtaining a further rectifying effect or simply for protecting the sensors 25 and 26 from foreign substances. In FIG. 5, 27 is a flow rate calculation unit, 28 is a display device that displays the mass flow rate calculated by the flow rate calculation unit 27 (may have a function for setting various measurement modes), 29 is a power source, Other cable connections for supplying other calculation coefficients are shown.
[0024]
FIG. 6 is a diagram showing a configuration example of a rectifier pipe provided with a rectifier according to an embodiment of the present invention, in which the rectifier pipe in which the rectifier described above is arranged is sandwiched between pipes having a smaller diameter. It is the schematic which shows a mode when doing.
A rectifier tube 30 according to an embodiment of the present invention includes the rectifier 10 of each embodiment described above and a rectifier tube body 31 having a diameter that matches the outflow portion 13 of the rectifier 10 and having the rectifier 10 disposed in a flow path. This rectifier pipe is installed in the middle of a pipe to efficiently eliminate swirling flow and drift (with short pressure loss and almost no pipe). The rectifying pipe 30 is arranged so as to rectify the fluid flowing from the upstream flow pipe 41 having an inner diameter smaller than the inner diameter of the flow path of the rectifying pipe main body 31 disposed on the upstream side of the rectifying pipe 30 by the rectifier 10. It was established. The function of the rectifying pipe 30 can be used more appropriately by incorporating it in the piping at the front stage of the flow meter.
[0025]
The rectifying pipe 30 according to this configuration example is disposed so as to be sandwiched between a pipe 41 as an upstream flow pipe and a pipe 42 as a downstream flow pipe. The pipe 41 and the pipe 42 are joined to the upstream inflow part 32 and the downstream outflow part 33 of the flow path of the rectifying pipe main body 31 by the flange 41a of the upstream flow pipe and the flange 42a of the downstream flow pipe, respectively. . Although the flange connection is illustrated here, it may be screwed or the like. In FIG. 6, as an example of the rectifying pipe 30, the flow path of the rectifying pipe main body 31 having the tapered portion 34 on the downstream side will be described, but the tapered portion 34 is used to adjust the flow path to the inner diameter of the pipe 42. It is a portion provided (in order to fill a step in diameter), and may have, for example, an arc shape. Although the flow pipe having a smaller diameter than the flow path of the rectifying pipe main body 31 (the flow path of the installation portion of the rectifier 10) is illustrated as the downstream pipe 42, a flow pipe having the same diameter is adopted without providing the tapered portion 34 or the like. Even so, the effect is obtained. Here, an example is shown in which the obstacle portion 11 has a side surface portion 11b that does not have a plane perpendicular to the flow and has a cross-sectional shape in the flow direction formed in an arcuate shape. Moreover, the effect of the rectifying pipe 30 is improved by providing the filter 35 in the flow path.
[0026]
【The invention's effect】
According to the present invention, it is not necessary to lengthen the piping, and the fluid can be adjusted to a stable flow. That is, according to the present invention, it is possible to rectify the fluid in the flow pipe with a shorter pipe length, no influence of the pipe, and with a small pressure loss. Further, according to the present invention, in the flowmeter using this rectifier, there is no need to separately calculate the pressure loss due to the rectifier itself at the time of measuring the flow velocity or flow rate, and the flow velocity or flow rate in the flow tube is represented by a predetermined position in the flow tube. Can be measured.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration example of a rectifier according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating another configuration example of the rectifier according to the embodiment of the present invention.
FIG. 3 is a diagram illustrating a configuration example of a rectifier according to another embodiment of the present invention.
FIG. 4 is a diagram illustrating a configuration example of a rectifier according to another embodiment of the present invention.
FIG. 5 is a diagram illustrating a configuration example of a flow meter including a rectifier according to an embodiment of the present invention.
FIG. 6 is a diagram illustrating a configuration example of a rectifier tube including a rectifier according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Thermal mass flowmeter, 10 ... Rectifier, 11 ... Obstacle part, 11a, 11b ... Side part of obstruction part, 12 ... Intermediate part, 12a ... Boundary part with outflow part of intermediate part, 12b ... Obstacle of intermediate part 13 ... Outflow part, 14, 14 ₁ , 14 ₂ , 14 ₃ , 14 ₄ ... hole (through hole), 15 ... cylindrical space, 20, 21, 22, 23 ... flow tube, 20 '... Flow path, 24, 35 ... filter, 25 ... temperature sensor, 26 ... heating temperature sensor, 27 ... flow rate calculation unit, 28 ... display device, 29 ... cable connection unit, 30 ... rectifier tube, 31 ... rectifier tube body, 32: Inlet part of rectifying pipe, 33 ... Outlet part of rectifying pipe, 34 ... Tapered part, 41 ... Upstream side pipe, 41a ... Upstream side pipe flange, 42 ... Downstream side pipe, 42a ... Downstream side pipe flange .

Claims (5)

In a rectifier arranged in a flow tube and rectifying a fluid flowing in the flow tube,
An obstacle having a circular cross section concentric with the flow tube, for restricting a fluid located in a central portion of the flow tube from the upstream side to the inner peripheral wall side of the flow tube. And
A column body portion downstream of the obstacle portion, a columnar intermediate portion concentric with the obstacle portion and having a cross section smaller than a radial cross section of the obstacle portion;
A column body part downstream from the intermediate part, and comprising a cylindrical outflow part concentric with the obstacle part and having a diameter matching the inner diameter of the flow tube;
The outflow portion is narrowed to the inner peripheral wall side of the flow tube by the obstruction portion, and has a plurality of holes for flowing out the fluid flowing on the side surface of the intermediate portion to the downstream side,
The plurality of holes among the holes have a rectifier in which a part or all of the inflow portion is located within the diameter of the obstruction portion when viewed from the front of the flow and corresponds to the outside of the intermediate portion. . 2. The rectifier according to claim 1, wherein the plurality of holes are a plurality of circular holes arranged uniformly on a circumference of a concentric circle of the outflow portion. The outflow portion forms a cylindrical space having the same diameter as that of the downstream flow tube so as to be integrally sandwiched between the upstream flow tube and the downstream flow tube on the downstream side of the outflow portion. The rectifier according to claim 1 or 2, characterized by the above. A rectifier tube comprising: the rectifier according to any one of claims 1 to 3; and a rectifier tube body having a diameter matching the outflow portion of the rectifier and having the rectifier disposed in a flow path, The fluid flowing from the upstream flow pipe having an inner diameter smaller than the inner diameter of the flow passage of the rectifying pipe body, which is arranged upstream of the rectifying pipe, is rectified by the rectifier. A rectifier tube characterized by being. A flowmeter comprising the rectifier according to any one of claims 1 to 3 disposed upstream of a flow velocity or flow rate measurement unit.

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