JP6690966B2 - Powder transfer system, flow control valve and flow meter - Google Patents

Description

  The present invention relates to a powder transfer system, a flow rate adjusting valve and a flow meter.

  As a powder conveying system that conveys powder by gas, Patent Document 1 below discloses a blast furnace pulverized coal blowing device (PCI: Pulverized Coal Injection). This apparatus is an apparatus that conveys pulverized coal extruded from a storage tank with a carrier gas such as nitrogen gas and blows it from the tuyere of a blast furnace. Many (several dozen) tuyere are arranged in the blast furnace, and pulverized coal is blown from each tuyere, but if the amount of pulverized coal blown from each tuyere is not uniform, A uniform refining reaction does not occur, which causes a decrease in productivity. Therefore, in blowing pulverized coal, it is necessary to make the amount of pulverized coal blown from each tuyere uniform.

  However, depending on the layout of the layout of the blast furnace and the blast furnace pulverized coal blowing device and the installation situation of related equipment around it, the length and shape (straight line / curve) of the transfer channel that transfers the pulverized coal to each tuyere of the blast furnace. And the pressure loss in each of the transfer passages is different, so that the pulverized coal flow rate is not the same. Therefore, in Patent Document 1, a powder flow rate measuring unit and a powder flow rate adjusting unit are provided in each of the plurality of transfer channels, and the absolute value of the pulverized coal flow rate in each transfer channel is grasped by the powder flow rate measuring unit. Then, the powder flow rate adjusting means adjusts the flow rate of the pulverized coal in each of the transfer channels to be uniform.

JP, 2011-12324, A

By the way, in the powder transfer system, the uneven flow of the powder during the transfer is a problem.
For example, when the transfer flow path includes a bent tube, the powder is unbalanced due to the centrifugal force when the powder flows through the bent tube. Such uneven distribution of the powder accelerates the wear of the pipe on the downstream side of the bent pipe. In particular, when the powder flow velocity is high, as in the blast furnace pulverized coal blowing device, the amount of wear of the pipe increases.
In addition, for example, if the powder flow is uneven, the powder flow rate measuring means will increase the measurement error of the powder flow rate. It is necessary to install a straight pipe of (S). Therefore, it is necessary to secure a large equipment installation space, which lengthens the transport flow path and increases the cost. Further, the powder flow rate measuring means measures the flow rate of the powder, for example, on the downstream side of the powder flow rate adjusting means, but the powder flow rate adjusting means gradually adjusts the flow path area of the transfer flow path to open. In the case of a valve, since a flow of powder is also formed in this flow rate adjusting valve, a straight pipe of a specified length must be installed between the flow rate adjusting valve and the powder flow rate measuring means. The powder flow rate measuring means may measure the powder flow rate on the upstream side of the powder flow rate adjusting means. However, if there is a bent pipe on the upstream side of the powder flow rate adjusting means, a predetermined length is provided between the bent pipe and the bent pipe. The straight pipe of must be installed.

  The present invention has been made in view of the above problems, and reduces the wear range of the transfer flow path due to the uneven flow of powder, and can reduce the space required for equipment installation. The purpose is to provide a regulating valve and a flow meter.

  In order to solve the above-mentioned problems, the present invention includes a transfer flow path for transferring powder in a gas, and the transfer flow path is provided with a drift forming portion that forms a drift of the powder, The powder conveying system employs a powder conveying system that has, on the downstream side of the drift forming portion, a deviation reducing device provided with a protrusion projecting to the flow surface on the side where the powder is eccentric.

  Further, in the present invention, when the cross-sectional area of the flow passage surface that does not pass through the protrusion is based on an imaginary line that divides the powder into the side where the powder is drifted and the opposite side, the flow passage surface that passes through the protrusion The cross-sectional area of is adopted such that the area on the side opposite to the side where the powder drifts is larger than the area on the side where the powder drifts.

  Further, in the present invention, the configuration is adopted in which the drift forming portion is a flow rate adjusting valve.

  Further, in the present invention, a configuration is adopted in which the drift forming portion is a bent pipe.

  Further, in the present invention, a configuration is adopted in which the transfer flow path is provided with a flow meter for measuring the flow rate of the powder, on the downstream side of the uneven flow reducing device.

  Further, in the present invention, a configuration is adopted in which the transport flow path is provided with a flow rate adjusting valve on the downstream side of the uneven flow reducing device.

  Further, in the present invention, there is provided a flow rate adjusting valve comprising an internal flow passage and a valve body that opens the internal flow passage from one side, wherein the outlet portion of the internal flow passage protrudes with respect to the flow passage surface on one side. The configuration is adopted in which the nonuniform flow reducing device including the protruding portion is connected.

  Further, in the present invention, a flow meter for measuring the flow rate of a fluid on the downstream side of a curved pipe provided with a curved flow passage that changes the flow direction of the fluid, and a drift reducing device connectable to the outlet of the curved flow passage. The uneven flow reducing device employs a configuration in which the uneven flow reducing device includes a protruding portion that projects toward the flow path surface outside the curved flow path.

  According to the present invention, in the transfer flow path for transferring the powder by gas, the non-uniform flow reducing device is provided on the downstream side of the non-uniform flow forming unit that forms the non-uniform flow of the powder, and the flow path surface on the non-uniform flow side of the powder The unevenly-flowing powder is reduced by forcibly guiding the powder, which is biased to one side of the flow path surface, toward the center of the flow path by the projecting protrusion. As a result, the length of uneven distribution of powder is shortened, the wear range of the transfer channel is reduced, and the restriction on the equipment installation space due to uneven distribution of powder is lifted, so space can be saved. You can

FIG. 1 is a system diagram of a blast furnace pulverized coal blowing device according to an embodiment of the present invention. It is a schematic diagram which shows the structure of the downstream area | region after the distribution of the conveyance flow path in embodiment of this invention. It is sectional drawing which shows the flow control valve to which the nonuniform flow reducing apparatus in embodiment of this invention was connected. It is an arrow AA figure of the flow control valve in FIG. FIG. 4 is a cross-sectional view taken along line BB of the drift reducing device in FIG. 3. FIG. 6 is a cross-sectional view taken along line CC of the drift reducing device in FIG. 5. It is sectional drawing which shows the example of a changed completely type of uneven flow reducing apparatus in embodiment of this invention. FIG. 8 is a cross-sectional view taken along line DD of the drift reducing device in FIG. 7. It is sectional drawing which shows the example of a changed completely type of uneven flow reducing apparatus in embodiment of this invention. It is a schematic diagram which shows one modification of arrangement | positioning of the nonuniform flow reducing device in the conveyance flow path in embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description exemplifies a case where the present invention is applied to a blast furnace pulverized coal blowing device.

FIG. 1 is a system diagram of a blast furnace pulverized coal blowing device 1 according to an embodiment of the present invention.
The blast furnace pulverized coal blowing device 1 (powder conveying system) conveys pulverized coal (powder) to the tuyere of the blast furnace 100 with a carrier gas (gas). The blast furnace pulverized coal blowing device 1 includes a bag filter 2, hoppers 3, 4, and 5, a carrier gas supply device 6, and a transfer passage 7.

The bag filter 2 receives pulverized coal and supplies the received pulverized coal to the hopper 3. The bag filter 2 includes a filter 2a that collects scattered pulverized coal when receiving the pulverized coal.
The hopper 3 stores the pulverized coal supplied from the bag filter 2, and supplies the stored pulverized coal to the hopper 4 by opening the opening / closing valve 3a.

The hopper 4 receives the pulverized coal supplied from the hopper 3, closes the open / close valve 3a and the open / close valve 4a, and pressurizes the open / close valve 4a with a high pressure nitrogen gas (not shown) so that the pressure becomes uniform with the hopper 5. It is opened to supply pulverized coal to the hopper 5.
The hopper 5 stores the pulverized coal supplied from the hopper 4, and supplies the stored pulverized coal to the transfer flow path 7 via the open / close valve 5a. The supply of pulverized coal from the hopper 5 to the transfer channel 7 is performed by cutting the pulverized coal stored in the hopper 5 by slightly increasing the pressure of the hopper 5 with a high-pressure nitrogen gas (not shown) than the pressure of the transfer channel 7. To go.

The carrier gas supply device 6 supplies carrier gas (high-pressure nitrogen gas) to the transfer passage 7 via the open / close valve 6a.
The transfer channel 7 transfers the pulverized coal supplied from the hopper 5 with the carrier gas supplied from the carrier gas supply device 6, and blows the transferred pulverized coal from the tuyere of the blast furnace 100. The transfer passage 7 includes a transfer pipe 8 and a distributor 9.

  The transfer pipe 8 is connected to the hopper 5 and the carrier gas supply device 6. The distributor 9 branches the transfer pipe 8 into a plurality of distribution pipes 10. The plurality of distribution pipes 10 are connected to the tuyere of the blast furnace 100, respectively. That is, the distribution pipes 10 are provided in the same number as the tuyere of the blast furnace 100.

Here, the distribution pipe 10 has a different shape (straight line / curved line) depending on the layout of the arrangement of the blast furnace 100 and the blast furnace pulverized coal blowing device 1, the installation situation of related facilities around the blast furnace 100, and the like in each transfer passage. Since the pressure loss is different, the flow rate of pulverized coal is not constant.
For this reason, the transport passage 7 is provided with the flow rate adjusting valve 16 and the flow meter 18 shown in FIG. 2 in each of the plurality of distribution pipes 10. That is, the region K1 of the transport passage 7 on the downstream side of the distributor 9 has a configuration as shown in FIG.

FIG. 2 is a schematic diagram showing the configuration of the downstream region K1 after the distribution of the transport passage 7 in the embodiment of the present invention.
As shown in FIG. 2, the transfer flow path 7 includes a short pipe 13, an opening / closing valve 14, a short pipe 15, a flow rate adjusting valve 16 (a nonuniform flow forming portion), a nonuniform flow reducing device 17, a flow meter 18, A straight pipe 19 and a bent pipe 20 are provided.

  The short pipe 13 is connected to the distribution pipe 10. The open / close valve 14 is connected to the downstream side of the short pipe 13 and opens / closes the transport passage 7. The short pipe 15 is connected to the downstream side of the on-off valve 14. The flow rate adjusting valve 16 is connected to the downstream side of the short pipe 15 and adjusts the flow rate of the pulverized coal in the distribution pipe 10. The uneven flow reducing device 17 is connected to the downstream side of the flow rate adjusting valve 16 and reduces the uneven flow of the pulverized coal formed by the flow rate adjusting valve 16.

  The flow meter 18 is connected to the downstream side of the drift reducing device 17 and measures the flow rate of pulverized coal. The flow meter 18 is, for example, a capacitance type flow meter. The flow meter 18 may be a known transmission and phase difference type microwave flow meter. The straight pipe 19 is connected to the downstream side of the flow meter 18 and ensures a specified length on the downstream side of the flow meter 18. That is, the straight pipe 19 prevents the flow meter 18 from being affected by the turbulent flow due to the collision of the pulverized coal in the bent pipe 20 connected to the downstream side. The bent pipe 20 is connected to the downstream side of the straight pipe 19.

Next, the configuration of the area K2 shown in FIG. 2 will be described with reference to FIGS. The flow rate adjusting valve 16 and the drift reducing device 17 arranged in the region K2 are connected to each other to form a unit.
FIG. 3 is a sectional view showing the flow rate adjusting valve 16 to which the nonuniform flow reducing device 17 according to the embodiment of the present invention is connected. FIG. 4 is an arrow AA view of the flow rate adjusting valve 16 in FIG. FIG. 5 is a cross-sectional view taken along the line BB of the drift reducing device 17 in FIG. FIG. 6 is a cross-sectional view taken along line CC of the drift reducing device 17 in FIG.

  In the following description, an XYZ orthogonal coordinate system may be set, and the positional relationship of each member may be described with reference to this XYZ orthogonal coordinate system. The transport direction of the pulverized coal in the transport passage 7 is the X-axis direction, and the direction orthogonal to the X-axis direction (the opening / closing direction of the valve body 22 described below) is the Y-axis direction, and the directions orthogonal to the X-axis direction and the Y-axis direction, respectively. The (rotational axis direction of the valve element 22 described later) is the Z-axis direction.

  As shown in FIG. 3, the flow rate adjusting valve 16 includes an internal flow path 21 and a valve body 22. The internal flow path 21 forms the transfer flow path 7, and is formed by a body 23 of the flow rate adjusting valve 16 and an inlet flange 24 connected to the body 23. The inlet flange 24 forms the inlet portion 21 a of the internal flow path 21. The body 23 forms the internal flow path 21 excluding the inlet portion 21a. The inlet flange 24 is fastened and fixed to the body 23 via a bolt 27 with a seal 25 interposed therebetween. The seal 25 is formed in an annular shape and is in contact with the valve body 22.

  The body 23 includes an outlet flange 26 that forms the outlet portion 21b of the internal flow passage 21. The outlet flange 26 is connected to the drift reducing device 17 via a bolt 27. Further, the body 23 houses the valve body 22. The valve body 22 is configured to open the internal flow passage 21 from one side (−Y side). The valve body 22 includes a valve body 22a and a valve shaft 22b. The valve body 22a is formed in a substantially semi-spherical shape. A cutout 22a1 is formed in the valve body 22a. The valve shaft 22b rotatably supports the valve body 22a around an axis (axis L1 in FIG. 4) extending in the Z-axis direction, and is held by the body 23.

  The notch 22a1 is formed in Λ (lambda) shape as shown in FIG. The notch 22a1 is formed in a Λ shape (isosceles triangle shape) with the axis L2 extending in the Y-axis direction as the center line. The tip of the notch 22a1 is arranged so as to face the + Y side. According to this configuration, when the valve body 22 is rotated about the axis L1, the internal flow passage 21 can be gradually opened from one side (−Y side), and the area of the cutout 22a1 is increased, so that the pulverized coal The flow rate can be adjusted. The cutout 22a1 is not limited to the Λ shape, and may be an arc shape, an elliptical shape, a polygonal shape, or another irregular shape.

  Returning to FIG. 3, the uneven flow reducing device 17 is connected to the outlet 21 b of the internal flow path 21. As shown in FIG. 5, the nonuniform flow reducing device 17 is formed in a cylindrical shape, and has flanges 30 that can be bolted at both ends thereof. The uneven flow reducing device 17 includes a protrusion 32 that projects from the flow path surface 31 on the side where the pulverized coal is unevenly flown. That is, since the flow rate adjusting valve 16 connected to the upstream side of the nonuniform flow reducing device 17 opens the internal flow path 21 from one side (-Y side) as shown in FIG. 4, the one side (-Y side). Uneven flow of pulverized coal (denoted by reference sign F in FIG. 5) occurs on the flow path surface 31 of the above.

  The protrusion 32 includes a first bulge portion 33a and a second bulge portion 33b. The first bulging portion 33a and the second bulging portion 33b each have a hill shape that smoothly bulges toward the downstream side of the transport flow path 7 in a cross-sectional view. The 1st bulge part 33a is formed in the side (-Y side) where the pulverized coal drifted. Moreover, the 2nd bulge part 33b is formed in the side (+ Y side) opposite to the side where the pulverized coal drifted. The flow passage surface 31 a that passes through the protrusion 32 of the transfer passage 7 is narrower than the flow passage surface 31 that does not pass through the protrusion 32. The flow passage surface 31 that does not pass through the protrusion 32 has the same size as the flow passage surface of the outlet portion 21b of the internal flow passage 21 of the flow rate adjusting valve 16.

  The first bulging portion 33a has a larger amount of protrusion than the second bulging portion 33b. That is, the distance D1 from the −Y side flow path surface 31 to the top of the first bulging portion 33a is greater than the distance D2 from the + Y side flow path surface 31 to the top of the second bulging portion 33b. Thereby, the cross-sectional area of the flow path surface 31a passing through the protrusion 32 is, as shown in FIG. 6, the side opposite to the side where the pulverized coal is deflected (−Y side) (+ Y side). Is larger in area. Here, the area of the side (−Y side) on which the pulverized coal drifts means the area of the flow path surface 31a on the left side of the paper with reference to the axis L1 in FIG. Further, the area on the opposite side (+ Y side) to the side where the pulverized coal drifts means the area of the flow path surface 31a on the right side of the drawing with reference to the axis L1 in FIG. The axis L1 is an imaginary line that divides the cross-sectional area of the flow path surface 31 that does not pass through the protrusion 32 into the side in which the pulverized coal drifts and the opposite side.

  According to the present embodiment, as shown in FIG. 2, in the transfer passage 7 that transfers pulverized coal by the carrier gas, the non-uniform flow reducing device 17 is provided on the downstream side of the flow rate adjusting valve 16 that forms the non-uniform flow of pulverized coal. As shown in FIG. 5, the pulverized coal which is drifted to one side (-Y side) of the flow path surface 31 is protruded by the protrusion 32 which is projected to the flow path surface 31 on the side (-Y side) where the pulverized coal is drifted. By forcibly guiding the flow path surface 31 toward the center side toward the + Y side, it is possible to reduce the drift of the pulverized coal. By reducing the uneven flow of the pulverized coal in this manner, it is possible to reduce the wear range on the downstream side (−Y side) of the pulverized coal on the downstream side of the flow rate adjusting valve 16.

  Further, since the uneven flow of pulverized coal is reduced immediately after the flow rate adjusting valve 16, the flow rate adjusting valve 16 and the flow meter 18 can be connected in a short distance as shown in FIG. That is, it is not necessary to connect a straight pipe having a specified length to the upstream side of the flow meter 18, and space saving and cost reduction can be achieved.

  As described above, according to the above-described present embodiment, in the blast furnace pulverized coal blowing device 1 including the transport passage 7 for transporting pulverized coal with the carrier gas, the unidirectional flow of pulverized coal is formed in the transport passage 7. A flow rate adjusting valve 16 is provided, and the transport flow path 7 is provided with a drift reducing device 17 that is provided on the downstream side of the flow rate adjusting valve 16 and has a protrusion 32 that projects toward the flow path surface 31 on the side where the pulverized coal drifts. By adopting such a configuration, it is possible to reduce the wear range of the transfer passage 7 due to the uneven flow of the pulverized coal and to save the space for equipment installation.

  Further, according to the present embodiment, the flow rate adjusting valve 16 is provided with the internal flow path 21 and the valve body that opens the internal flow path 21 from one side. By adopting a configuration in which the nonuniform flow reducing device 17 including the projecting portion 32 protruding to the flow channel surface 31 is connected, the wear range of the transport flow channel 7 due to the nonuniform flow of pulverized coal on the downstream side of the flow rate adjusting valve 16. It is also possible to reduce the installation cost and to save space for equipment installation.

  The preferred embodiments of the present invention have been described above with reference to the drawings, but the present invention is not limited to the above embodiments. The shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the spirit of the present invention.

  For example, the present invention may employ the following modifications. In the following description, configurations that are the same as or equivalent to those of the above-described embodiment will be assigned the same reference numerals, and description thereof will be simplified or omitted.

FIG. 7 is a cross-sectional view showing a modified example of the drift reducing device 17 according to the embodiment of the present invention. FIG. 8 is a cross-sectional view taken along the line DD of the drift reducing device 17 in FIG. 7.
The protrusion 32A of the drift reducing device 17 illustrated in FIG. 7 includes a trapezoidal first bulge 33a and a second bulge 33b in a cross-sectional view. The first bulge 33a includes an inclined surface 33a1 forming a trapezoidal leg, a flat surface 33a2 forming an upper base of the trapezoid, and an inclined surface 33a3 forming another trapezoidal leg. The second bulge 33b also includes an inclined surface 33b1 forming a trapezoidal leg, a flat surface 33b2 forming an upper base of the trapezoid, and an inclined surface 33b3 forming another trapezoidal leg. As shown in FIG. 8, the flow path surface 31a passing through the protrusion 32A has a circular shape eccentric to the reference flow path surface 31 on the side (−Y side) on which the pulverized coal is eccentric (−Y side). Has been formed. Although the protrusion 32 of the above-described embodiment has a streamlined shape, the protrusion 32A according to this modification is a combination of linear shapes that is relatively easy to process, and thus the manufacturing cost can be reduced.

FIG. 9 is a cross-sectional view showing a modified example of the drift reducing device 17 according to the embodiment of the present invention.
In the protrusion 32B of the drift reducing device 17 shown in FIG. 9, the inclined surface 33a3 and the inclined surface 33b3 on the downstream side are cut out. That is, the action of forcibly guiding the pulverized coal that is biased to one side (−Y side) of the flow path surface 31 toward the + Y side toward the center side of the flow path surface 31 is performed on the upstream side of the protrusion 32B. The inclined surface 33a3 and the inclined surface 33b3 on the downstream side may be cut out to form the vertical surface 33a4 and the vertical surface 33b4. As a result, the length of the protrusion 32B is shortened, so that the total length of the drift reducing device 17 can be shortened.

FIG. 10 is a schematic diagram showing a modified example of the arrangement of the drift reducing device 17 in the transport passage 7 in the embodiment of the present invention.
The transfer passage 7 shown in FIG. 10 includes a flow meter 18 downstream of the bent pipe 20 (uneven flow forming portion). The term "bent pipe" as used herein means a pipe having a bent flow path that changes the flow direction of the fluid, and includes, for example, an elbow, reducer, T (tee), Y, hose, bend and the like. The flow meter 18 includes a drift reducing device 17 that can be connected to the outlet of the bent flow path of the bent pipe 20. That is, the flow meter 18 and the drift reducing device 17 arranged in the region K3 are connected to each other to form a unit. The non-uniform flow reduction device 17 includes a protrusion 32 (see FIG. 5) protruding from the flow passage surface outside the curved flow passage of the bent pipe 20. Since the uneven flow of the pulverized coal is also formed in the bent pipe 20, the uneven flow reducing device 17 is connected to the downstream side of the bent pipe 20 to reduce the uneven flow of the pulverized coal immediately after the bent pipe 20 to reduce the carrier flow. The wear range of the road 7 can be reduced. Further, the uneven flow reducing device 17 can connect the flow meter 18 for measuring the flow rate of the pulverized coal on the downstream side of the bent pipe 20 and the bent pipe 20 in a short distance, thereby saving space.

  Further, for example, in the above-described embodiment, the protrusion 32 of the nonuniform flow reducing device 17 is a bulge portion (second bulge portion 33b) on the side opposite to the side where the pulverized coal is nonuniformly flowed so as to smooth the flow of fluid. However, the second bulging portion 33b may be omitted.

  Further, for example, in the above-described embodiment, the flow rate adjusting valve 16 in which the inlet portion 21a and the outlet portion 21b of the internal flow path 21 are aligned is adopted, but the present invention is not limited to this configuration, and the outlet portion 21b serves as the inlet portion 21a. It may be arranged so as to be bent, for example, an L port or a T port. The flow rate adjusting valve 16 may be a ball valve or the like.

  Further, for example, in the above-described embodiment, the configuration in which the transport flow path 7 is provided with the flow meter 18 on the downstream side of the nonuniform flow reducing device 17 is exemplified, but the configuration is provided with the flow rate adjusting valve 16 on the downstream side of the nonuniform flow reducing device 17. May be. For example, the transport passage 7 may be formed by connecting the bent pipe 20 (uneven flow forming portion), the uneven flow reducing device 17, and the flow rate adjusting valve 16 in this order.

  Further, for example, in the above-described embodiment, the powder transfer system is applied to the blast furnace pulverized coal blowing device 1, but the present invention is not limited to this configuration, and may be applied to a system for transferring powder in the food or pharmaceutical field, for example. You can

1 Blast furnace pulverized coal blowing device (powder transfer system)
7 Transport flow path 16 Flow rate adjusting valve (deviation part)
17 Uneven Flow Reduction Device 18 Flow Meter 20 Bent Pipe (Uneven Flow Forming Section)
21 Internal Flow Path 21b Exit Port 31 Flow Path Surface 31a Flow Path Surface 32 Projection 32A Projection 32B Projection

Claims (8)

Equipped with a transfer channel that transfers powder with gas,
The carrier flow path is provided with a drift forming portion that forms a drift of the powder,
The transfer flow path has a first bulge portion, which protrudes with respect to a flow path surface on which the powder is unevenly flowed, and a flow path surface on a side opposite to the flow path surface on which the powder is flowed, on the downstream side of the flow deviation forming portion. And a second bulging portion that protrudes,
The first bulging portion has a larger protrusion amount than the second bulging portion,
The powder conveying system, wherein a cross-sectional shape of the conveying passage including the first bulging portion and the second bulging portion in a direction orthogonal to the conveying passage is formed as a curved surface.   When the cross-sectional area of the flow path surface that does not pass through the protrusion is based on an imaginary line that divides the powder into a side where the powder drifts and the opposite side, the cross-sectional area of the flow path surface that passes through the projection is 2. The powder conveying system according to claim 1, wherein the area on the side opposite to the side where the powder has flowed is larger than the area on the side where the powder has flowed in the flow path.   The powder conveying system according to claim 1 or 2, wherein the uneven flow forming portion is a flow rate adjusting valve.   The powder conveying system according to claim 1 or 2, wherein the uneven flow forming portion is a bent pipe.   The powder transfer system according to any one of claims 1 to 4, wherein the transfer flow path is provided with a flow meter for measuring a flow rate of the powder on a downstream side of the uneven flow reducing device. .   The powder carrying system according to claim 1 or 2, wherein the carrying channel is provided with a flow rate adjusting valve on the downstream side of the uneven flow reducing device. A flow rate adjusting valve comprising an internal flow passage and a valve body that opens the internal flow passage from one side,
At the outlet of the internal flow passage, a non-uniform flow reducing device including a first bulging portion protruding toward the flow passage surface on one side and a second bulging portion protruding toward the flow passage surface on the opposite side of the one side is connected. Has been done,
The first bulging portion has a larger protrusion amount than the second bulging portion,
A flow rate adjusting valve, wherein a cross-sectional shape of the internal flow path including the first bulging part and the second bulging part in a direction orthogonal to the internal flow path is formed as a curved surface. A flow meter for measuring the flow rate of a fluid at the downstream side of a curved pipe provided with a curved flow path that changes the flow direction of the fluid,
Equipped with a drift reducing device connectable to the outlet of the curved flow path,
The uneven flow reducing device includes a first bulge portion that projects toward a flow passage surface outside the curved flow passage and a second bulge portion that projects toward a flow passage surface inside the curved flow passage.
The first bulging portion has a larger protrusion amount than the second bulging portion,
A flowmeter, wherein a cross-sectional shape of the curved flow channel including the first bulge portion and the second bulge portion in a direction orthogonal to the curved flow channel is formed as a curved surface.

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