JP7403803B2 - flow rate control device - Google Patents

Description

The present invention relates to a flow rate control device that controls the flow rate of fluid flowing in a pipe.

BACKGROUND ART Some air piping that transports air, which is a fluid, is equipped with a flow rate adjustment device that makes the air flow more easily when the flow rate increases (see, for example, Patent Document 1).

Furthermore, steam as a fluid is supplied to steam-using devices such as heat exchangers through steam piping.

Japanese Patent Application Publication No. 2005-240598

In the above-mentioned steam piping, when steam flows from high pressure to low pressure during air supply, the flow velocity in the piping increases due to volumetric expansion, and water hammer may occur. This water hammer may cause damage to the piping.

SUMMARY OF THE INVENTION An object of the present invention is to provide a flow rate control device that reduces water hammer by controlling the flow rate of a fluid to reduce the flow rate when the flow rate is high.

A flow rate control device for controlling the flow rate of fluid provided by the present invention is provided in a pipe through which fluid flows from upstream to downstream, and includes a rotation mechanism. The rotation mechanism includes a plate member whose state can be switched between a first state in which the surface direction is substantially parallel to the fluid flow direction and a second state in which the surface direction intersects the fluid flow direction by rotation; A support means provided on an inner wall surface of a pipe to rotatably support a plate-like member, the upstream end of the plate-like member being closer to the central axis of the pipe than the downstream end in a second state. It has a support means for supporting the plate-like member in the first position, and a biasing means for biasing the plate-like member in the direction of the first state. Further, the plate member has a protruding piece that protrudes in an inclined direction that is a direction toward the central axis of the pipe and a direction from downstream to upstream, and can be switched between the first state and the second state according to the flow rate of the fluid. It will be done.

In the first state, at least a portion of the plate member may be in contact with an inner wall surface of the pipe.

The rotation mechanism may include a stopper that defines an angle of inclination of the plate member in the second state with respect to the fluid flow direction.

A plurality of the rotation mechanisms may be provided, and the plurality of rotation mechanisms may be disposed on the inner wall surface of the pipe at the same position in the fluid flow direction and at positions where they do not interfere with each other.

The plurality of rotation mechanisms described above are four rotation mechanisms: a first rotation mechanism, a second rotation mechanism, a third rotation mechanism, and a fourth rotation mechanism, and the first rotation mechanism and the second rotation mechanism are The third rotation mechanism and the fourth rotation mechanism may be arranged so as to face each other.

According to this invention, when the fluid that is about to pass through the flow rate control device has a low flow rate, the plate member is in the first state and the flow path is expanded, and the fluid is about to pass through the flow rate control device. When the fluid has a high flow rate, the plate-like member is in the second state, and the flow path is in a reduced (squeezed) state. Therefore, a high flow rate fluid slows down as it passes through the flow rate control device. This makes it possible to reduce water hammer, extend the life of piping equipment, and ensure stable operation of equipment such as steam-using equipment using piping equipment.

FIG. 1 is a longitudinal sectional view of a flow rate control device according to an embodiment of the present invention. 2 is a cross-sectional view taken along line II in FIG. 1. FIG. FIG. 3 is a plan view of a first rotation mechanism included in the flow rate control device according to the embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a flow rate control device according to an embodiment of the present invention. 5 is a cross-sectional view taken along line I'-I' in FIG. 4. FIG. FIG. 7 is a longitudinal sectional view and a plan view of a first rotation mechanism according to another embodiment of the invention. FIG. 6 is a vertical cross-sectional view of two flow rate control devices according to another embodiment of the invention.

A flow rate control device that is an embodiment of the present invention will be described with reference to the drawings. Note that the configuration of the present invention is not limited to the embodiment.

FIG. 1 is a longitudinal cross-sectional view of a flow rate control device 1 according to an embodiment of the present invention. FIG. 1 shows a flow rate control device 1 disposed within a pipe 100. As shown in FIG. Further, FIG. 2 is a cross-sectional view taken along line II in FIG. 1. FIG. 3 is a plan view of the first rotation mechanism 20 included in the flow rate control device 1. Note that FIG. 1 shows the state of the flow rate control device 1 at a low flow rate.

The flow rate control device 1 is provided in a pipe 100 through which fluid flows from upstream to downstream, and controls the flow rate of the fluid. The flow rate control device 1 is disposed, for example, in a steam pipe (piping) 100 that supplies steam (fluid) to steam-using equipment such as a heat exchanger. In FIG. 1, steam flows from an upstream supply source (not shown) through the pipe 100 in the direction of arrow A (approximately horizontal direction), passes through the flow rate control device 1, and flows to downstream steam-using equipment (not shown). Supplied. That is, the inside of the pipe 100 becomes a fluid flow path.

The flow rate control device 1 controls the flow rate of the fluid by expanding and contracting the flow path according to the flow rate of the fluid that is about to pass through the flow rate control device 1. Specifically, when the fluid passing through the flow rate control device 1 has a low flow rate (low flow rate), the flow path is in an expanded state. On the other hand, when the fluid passing through the flow rate control device 1 has a high flow rate (at high flow rate), the flow path is in a reduced (squeezed) state. In this case, since the flow path is reduced, the high flow rate fluid will be decelerated when it passes through the flow rate control device 1. Although the piping 100 has a substantially horizontal piping direction, which is the direction in which fluid flows, the flow rate control device of the present invention can be applied to piping in a direction other than the above-mentioned direction.

The flow rate control device 1 includes four rotating mechanisms (a first rotating mechanism 20, a second rotating mechanism 21, a third rotating mechanism 22, a fourth rotating mechanism 23), and the like. The plurality of rotation mechanisms 20 to 23 are arranged at the same position in the direction of fluid flow (direction of arrow A) and at positions where they do not interfere with each other. In this embodiment, as shown in FIGS. 1 and 2, the first rotation mechanism 20 and the second rotation mechanism 21 face the inner wall surface of the pipe 100 at the same position in the direction of arrow A, and the third rotation mechanism The mechanism 22 and the fourth rotation mechanism 23 are arranged to face each other. More specifically, it is arranged at a position where a line segment connecting the first rotation mechanism 20 and the second rotation mechanism 21 and a line segment connecting the third rotation mechanism 22 and the fourth rotation mechanism 23 intersect at right angles. It is set up. Note that since each of the rotation mechanisms 20 to 23 has the same configuration, only the configuration of the first rotation mechanism 20 will be described in detail.

As shown in FIG. 3, the first rotation mechanism 20 includes a baffle plate 30, a support means 40, a coil spring 50, and the like. The first rotation mechanism 20 expands and contracts the flow path of the piping 100 by rotating the baffle plate 30 .

The baffle plate 30 is a plate-shaped member made of metal such as stainless steel, and is rotatably supported by the support means 40. In this embodiment, the baffle plate 30 can be switched between a first state and a second state by rotation. In the first state, as shown in FIG. 1, the surface direction of the baffle plate 30 is parallel to the direction of arrow A. Further, as shown in FIG. 2, a portion of the baffle plate 30 is in contact with the inner wall surface of the pipe 100 in the first state. Note that, in the first state, the surface direction of the baffle plate 30 does not need to be precisely parallel to the direction of arrow A, but only needs to be substantially parallel.

The second state is a state in which the surface direction of the baffle plate 30 intersects the direction of arrow A, as shown in FIG. Specifically, the second state is a state in which the upstream end of the baffle plate 30 is located closer to the central axis of the pipe 50 than the downstream end. The baffle plate 30 is in a first state to expand the flow path of the piping 100 when the flow rate is low, and is in a second state to reduce (squeeze) the flow path of the piping 100 when the flow rate is high. Note that in the second state, the angle (inclination angle) of the baffle plate 30 with respect to the fluid flow direction is, for example, 20 degrees.

The support means 40 includes a core rod 41, a fixing plate 42, and the like. The core rod 41 is inserted through a shaft tube 31 formed at one end of the baffle plate 30, a shaft tube 43 formed at one end of the fixed plate 42, and a coil spring 50. The fixing plate 42 is fixed to the inner wall surface of the pipe 50 by welding or the like.

Further, the baffle plate 30 has a claw 32 formed at the other end opposite to the shaft cylinder 31. The pawl 32 is a protruding piece that protrudes in an inclined direction (direction of arrow B), which is a direction toward the central axis of the pipe 100 and a direction from downstream to upstream, when the baffle plate 30 is in the first state, as shown in FIG. . The angle of inclination of the claw 32 with respect to the surface direction of the baffle plate 30 is, for example, 50 degrees. Since the pawl 32 protrudes in a direction intersecting the direction of arrow A, it acts as a fluid resistance. Therefore, the claw 32 receives a force from the fluid in a direction that brings the baffle plate 30 into the second state. Therefore, due to the claws 32, a pressure loss occurs between the pressure of the fluid on the upstream side of the baffle plate 30 (fluid control device 1) and the pressure of the fluid on the downstream side. Pressure loss increases as the velocity of the fluid increases. Using this pressure loss as power, the baffle plate 30 rotates from the first state to the second state. However, since the pressure loss is small at low flow speeds, the baffle plate 30 is maintained in the first state by the biasing force of the coil spring 50. On the other hand, at high flow rates, the pressure loss increases, so the baffle plate 30 rotates from the first state to the second state against the biasing force.

Note that, although the claws 32 are integrally formed with the baffle plate 30 by press working or the like, the invention is not particularly limited to this. The claws may be fixed to the baffle plate by welding or the like.

The coil spring 50 is made of metal such as stainless steel. As shown in FIG. 3, one end of the coil spring 50 contacts the upper surface of the baffle plate 30, and the other end contacts the upper surface of the fixed plate 42. That is, the coil spring 50 is a biasing means that biases the baffle plate 30 in the direction of the first state. Note that the configuration using the coil spring 50 may not be used as long as the configuration biases the baffle plate. For example, a leaf spring may be used.

Next, the operation of the flow rate control device 1 will be explained with reference to FIGS. 1 and 2 and FIGS. 4 and 5. Specifically, the operation of the flow rate control device 1 at low flow rates and high flow rates will be described. In the present embodiment, for example, a low flow rate will be described as a flow rate of 0 m/sec or more and less than 20 m/sec, and a high flow rate will be described as a flow rate of 20 m/sec or more. Note that FIG. 4 shows the state of the flow rate control device 1 at a high flow rate. FIG. 5 is a cross-sectional view taken along line I'-I' in FIG.

At low flow rates, the pawls 32 cause a pressure loss between the fluid pressure upstream and downstream of the baffle plate 30 (fluid control device 1). However, since the pressure loss is small, the urging force by the coil spring 50 is stronger than the power to rotate the baffle plate 30 due to the pressure loss. Therefore, the baffle plate 30 is in the first state as shown in FIGS. 1 and 2. Therefore, at a low flow rate, the fluid flow path is expanded, and even if the fluid passes through the flow rate control device 1, the flow rate hardly changes. Note that the claws 32 act as resistance to the fluid, but do not have a large effect that hinders the flow of the fluid.

Furthermore, when the fluid passing through the flow rate control device 1 changes from a low flow rate to a high flow rate, the pressure loss becomes larger than when the flow rate is low, and the power to rotate the baffle plate 30 due to the pressure loss is greater than that of the coil. The biasing force is stronger than that of the spring 50. Therefore, the baffle plate 30 begins to rotate from the first state to the second state against the urging force. Then, since the surface direction of the baffle plate 30 is also in a direction intersecting the direction of arrow A, the baffle plate 30 itself also acts as a resistance to the fluid. Therefore, the pressure loss becomes even larger. Thereby, the baffle plate 30 will be in the second state as shown in FIGS. 4 and 5. Then, at high flow velocity, the baffle plate 30 is maintained in the second state. Therefore, at a high flow rate, the fluid flow path becomes smaller than at a low flow rate. Therefore, the fluid having a high flow rate is decelerated by passing through the flow rate control device 1 and becomes a low flow rate.

After that, when the fluid passing through the flow rate control device 1 changes from a high flow rate to a low flow rate, the urging force by the coil spring 50 becomes stronger than the power to rotate the baffle plate 30 due to pressure loss again. . Therefore, the baffle plate 30 rotates from the second state to the first state.

As described above, by arranging the flow rate control device in the piping, the baffle plate is in the first state at low flow speeds and the flow path is expanded, and the baffle plate is in the first state at high flow speeds. There are two states, and the flow path is reduced (squeezed). Therefore, a high flow rate fluid slows down as it passes through the flow rate control device. This makes it possible to reduce water hammer, extend the life of piping equipment, and ensure stable operation of equipment such as steam-using equipment using piping equipment.

Further, since the configuration uses pressure loss as power, it can be a simple configuration that does not use an actuator or the like.

Furthermore, in the first state, a part of the baffle plate is in contact with the inner wall surface of the pipe, and the baffle plate is held between the coil spring and the inner wall surface, so the flow path is expanded. This prevents the baffle plate from vibrating or the like in the state where it is being held.

Although the flow rate control device of the above-described embodiment includes four rotation mechanisms, any number of rotation mechanisms can be adopted depending on the size of the piping, the type of fluid, and the like.

The size, shape and inclination angle of the baffle plate, the size, shape and inclination angle of the pawl, etc. in the above-described embodiments can be arbitrarily configured depending on the amount of reduction of the flow path, the urging force of the urging means, etc. .

Moreover, a stopper may be provided in the configuration of the rotation mechanism of the above-described embodiment to define the inclination angle of the baffle plate. For example, there is a rod-shaped stopper 210 as shown in FIGS. 6(A) and 6(B). 6(A) is a longitudinal cross-sectional view of the first rotating mechanism 200, and FIG. 6(B) is a plan view of the first rotating mechanism 200. The first rotation mechanism 200 has the same configuration as the first rotation mechanism 20 described above except for the stopper 210.

One end (fixed end) of the stopper 210 is fixed to the shaft cylinder 43 of the fixed plate 41 by welding or the like. In the first state, the baffle plate 30 does not contact the free end of the stopper 210, as shown by the solid line in FIG. 6(A). On the other hand, in the second state, the baffle plate 30 comes into contact with the free end of the stopper 210, as shown by the broken line in FIG. 6(A). Therefore, the stopper 210 restricts further rotation of the baffle plate 30. Thereby, the inclination angle of the baffle plate 30 in the second state can be reliably maintained at the intended angle.

Furthermore, in the above-described embodiment, one flow rate control device is disposed within the pipe, but the present invention is not particularly limited to this. A plurality of flow rate control devices may be arranged within the pipe. For example, as shown in FIG. 7, two flow rate control devices 500 and 501 may be disposed within the pipe 100. Flow rate control device 501 is arranged downstream of flow rate control device 500. Each flow rate control device 500, 501 has a configuration having four rotation mechanisms similar to the above-described flow rate control device 1. Note that each flow rate control device 500, 501 may have one rotating mechanism, for example.

The present invention is useful for controlling the flow rate of fluid in piping such as steam piping that supplies steam to steam-using equipment.

1 Flow velocity control device 20-23 Rotation mechanism 30 Baffle plate (plate-shaped member)
32 Claw (protruding piece)
40 Supporting means 50 Coil spring (biasing means)
100 Piping

Claims (5)

A flow rate control device that is installed in a pipe in which fluid flows from upstream to downstream and controls the flow rate of the fluid,
a plate member whose state can be switched by rotation between a first state in which the surface direction is substantially parallel to the fluid flow direction and a second state in which the surface direction intersects the fluid flow direction; and an inner wall surface of the piping. support means for rotatably supporting the plate-like member, the upstream end of the plate-like member being closer to the center axis of the piping than the downstream end in the second state; a rotation mechanism having a support means for supporting the plate-like member in the first state;
Equipped with
The plate-like member has a protruding piece that protrudes in an inclined direction that is a direction toward the central axis of the piping and a direction from downstream to upstream, and the plate-like member can be in the first state and the second state depending on the flow rate of the fluid. A flow rate control device characterized by being able to switch. 2. The flow rate control device according to claim 1, wherein at least a portion of the plate member is in contact with an inner wall surface of the pipe in the first state. 3. The flow rate control device according to claim 1, wherein the rotation mechanism includes a stopper that defines an angle of inclination of the plate-like member with respect to the fluid flow direction in the second state. having a plurality of the rotation mechanisms;
According to any one of claims 1 to 3, the plurality of rotation mechanisms are arranged on the inner wall surface of the piping at the same position in the fluid flow direction and at positions that do not interfere with each other. flow rate control measures. The plurality of rotation mechanisms are four rotation mechanisms: a first rotation mechanism, a second rotation mechanism, a third rotation mechanism, and a fourth rotation mechanism,
Claim 4, wherein the first rotation mechanism and the second rotation mechanism are arranged to face each other, and the third rotation mechanism and the fourth rotation mechanism are arranged to face each other. The flow rate control device described.

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