JP6836456B2 - Check valve - Google Patents

Description

The present application relates to a check valve.

For example, as disclosed in Patent Document 1, it is known that drain generated by steam-using equipment or the like is collected in a recovery pipe. In Patent Document 1, the high-temperature drain generated by the condensation of steam in the steam-using equipment flows into the recovery pipe via a steam trap of the branch pipe, etc., and merges with the drain of the recovery pipe to be recovered.

Japanese Unexamined Patent Publication No. 50-55701

By the way, there is a possibility that an impact (water hammer) may occur in the recovery pipe as described above. Part of the high-temperature drain discharged from the steam trap may re-evaporate into steam (flash steam). When the steam flows into the recovery pipe, a relatively large vapor mass (space) is formed in the recovery pipe. The lump of steam comes into contact with the low-temperature drain and condenses rapidly, so that the space where the steam existed becomes a vacuum state at once. A water hammer is generated when the drain flows into the space in this vacuum state at a stretch and the drains collide with each other or the drain collides with the pipe wall.

In addition, water hammer may occur in branch pipes, steam traps, and the like. When the low-temperature drain flows back from the recovery pipe to the branch pipe, the steam existing in the branch pipe, steam trap, etc. comes into contact with the low-temperature drain and rapidly condenses. Then, as in the above, there is a risk that a water hammer will occur. If a large water hammer is generated, it may cause noise and damage to the pipe.

The technique disclosed in the present application has been made in view of such circumstances, and an object thereof is to provide a check valve capable of preventing backflow of fluid and suppressing the generation of water hammer on the downstream side. It is in.

The check valve of the present application includes a casing, a valve portion, and a first impeller. The casing is formed with a first inlet and outlet of the first fluid, and a valve chamber communicating with the first inlet and outlet. The valve portion is provided in the valve chamber and opens and closes the first inflow port. The first impeller is provided in the casing and diffuses the first fluid.

According to the check valve of the present application, it is possible to prevent the backflow of the fluid and suppress the occurrence of water hammer on the downstream side.

FIG. 1 is a piping system diagram showing a schematic configuration of a drain recovery system according to an embodiment. FIG. 2 is a cross-sectional view showing a schematic configuration of a check valve according to an embodiment. FIG. 3 is a schematic front view showing the check valve according to the embodiment as viewed from the upstream side. FIG. 4 is a perspective view showing the check valve according to the embodiment as viewed from above on the upstream side, with a part omitted. FIG. 5 is a perspective view showing the check valve according to the embodiment as viewed from below on the upstream side, with a part omitted. FIG. 6 is a view corresponding to FIG. 2 showing a state in which the check valve according to the embodiment is closed.

Hereinafter, embodiments of the present application will be described with reference to the drawings. It should be noted that the following embodiments are essentially preferred examples and are not intended to limit the scope of the techniques disclosed in the present application, their applications, or their uses.

The drain recovery system 1 of the present embodiment heats the object with steam and recovers the drain generated by the heating. As shown in FIG. 1, the drain recovery system 1 includes a steam supply pipe 11, a steam-using device 13, a drain recovery pipe 14, a plurality of drain discharge pipes 16, and a check valve 20 according to a claim of the present application. It has.

The steam supply pipe 11 is connected to the steam-using device 13. The steam supply pipe 11 is connected to, for example, a boiler facility (not shown), and the steam generated by the boiler facility is supplied to the steam-using device 13. The steam supply pipe 11 is provided with a pressure reducing valve 12 for adjusting the pressure of steam. The steam-using device 13 is, for example, a heat exchanger, and the steam supplied from the steam supply pipe 11 dissipates heat to the object and condenses the object, so that the object is heated. Steam becomes a drain (condensate) by condensing. That is, in the steam-using device 13, the latent heat of condensation of steam is applied to the object, and the object is latently heated.

The drain recovery pipe 14 is connected to the steam-using device 13. In the drain recovery pipe 14, the drain generated by the condensation of steam in the steam-using equipment 13 is recovered. The drain recovery pipe 14 is provided with a liquid pumping device 15. The liquid pumping device 15 is a pump that pumps the drain generated by the steam-using device 13 to the downstream side through the drain recovery pipe 14. For example, in the liquid pumping device 15, the drain of the steam-using device 13 flows in through the drain recovery pipe 14 and is temporarily stored. When the amount of drain stored reaches a predetermined amount, a high-pressure working gas is introduced into the liquid pumping device 15, and the stored drain is pressure-fed downstream by the pressure of the working gas. When the drain is pumped, the drain flows from the steam-using device 13 into the liquid pumping device 15 again and is stored. In this way, in the liquid pumping device 15, the inflow of the drain and the pumping (discharge) of the drain are alternately performed.

The plurality of drain discharge pipes 16 are connected between the steam supply pipe 11 and the drain recovery pipe 14. Specifically, the drain discharge pipe 16 has an upstream end connected to the steam supply pipe 11 and a downstream end connected to the drain recovery pipe 14 via a check valve 20. The plurality of drain discharge pipes 16 are provided at intervals (for example, 20 to 30 m) from each other. The drain discharge pipe 16 is for flowing the drain generated in the steam supply pipe 11 to the drain recovery pipe 14. That is, a part of the steam may condense in the steam supply pipe 11 to become a drain, and the drain is collected in the drain recovery pipe 14 via the drain discharge pipe 16 and the check valve 20.

A steam trap 17 is provided in the middle of the drain discharge pipe 16. In the steam trap 17, the drain generated in the steam supply pipe 11 flows in through the drain discharge pipe 16. The steam trap 17 automatically discharges only the inflowing drain to the downstream side due to the pressure difference between the upstream and downstream sides (the difference between the pressure on the upstream side and the pressure on the downstream side). In fact, the drain mixed with steam flows into the steam trap 15. In this way, the drain generated in the steam supply pipe 11 merges with the drain generated in the steam-using equipment 13 in the drain recovery pipe 14 and is pumped to the downstream side. The drain recovery pipe 14 is located below the steam supply pipe 11, and most of the drain discharge pipe 16 extends vertically, and its downstream end is bent upward and connected to the check valve 20 from below. ing.

<Construction of check valve>
The check valve 20 is provided at a connection portion between the drain recovery pipe 14 and the drain discharge pipe 16. The check valve 20 allows the flow of fluid from the drain discharge pipe 16 to the drain recovery pipe 14, while blocking the flow of fluid (backflow) from the drain recovery pipe 14 to the drain discharge pipe 16. Further, the check valve 20 diffuses the steam generated in the drain discharge pipe 16, that is, the steam (flash steam) obtained by re-evaporating a part of the drain discharged from the steam trap 17 outward. The liquid drain and the gas vapor (flash vapor) are examples of fluids.

As shown in FIGS. 2 to 6, the check valve 20 includes a casing 21 and a valve body 30. The valve body 30 is provided in the casing 21. In FIGS. 2 to 6, the upper side is the upper part and the lower side is the lower part. Further, in FIGS. 2 and 5, the lower side is the upstream side and the upper side is the downstream side in the axial direction of the first inflow port 22, and the left side is the axial center direction of the second inflow port 23 and the outflow port 24. It is the upstream side and the right side is the downstream side.

The casing 21 is formed in a substantially T shape, and a fluid flow path is formed inside. Specifically, the casing 21 is formed with two inlets (first inlet 22 and second inlet 23) and one outlet 24. The second inflow port 23 and the outflow port 24 are formed in a circular shape coaxial with each other. The first inflow port 22 is formed in a circular shape, and its axis is orthogonal to the axis of the second inflow port 23 and the outflow port 24. A drain discharge pipe 16 is connected to the first inflow port 22, and a drain recovery pipe 14 is connected to the second inflow port 23 and the outflow port 24. That is, the fluid (high temperature drain or steam) of the drain discharge pipe 16 flows into the first inflow port 22 (white arrow shown in FIG. 2), and the fluid of the drain recovery pipe 14 (white arrow shown in FIG. 2) flows into the second inflow port 23. (Low temperature drain) flows in (thick black arrow shown in FIG. 2). The fluid flowing from the drain discharge pipe 16 into the first inflow port 22 corresponds to the first fluid according to the claim of the present application, and the fluid flowing into the second inflow port 23 from the drain recovery pipe 14 corresponds to the first fluid according to the claim of the present application. Corresponds to two fluids.

In the casing 21, a valve chamber 25 is formed between the second inflow port 23 and the outflow port 24. The valve chamber 25 is formed in a substantially columnar shape coaxial with the second inflow port 23 and the outflow port 24. In the casing 21, the first inflow port 22, the second inflow port 23, and the outflow port 24 communicate with each other via the valve chamber 25. In the casing 21, the first inflow port 22, the second inflow port 23, the outflow port 24, and the valve chamber 25 form a fluid flow path. A valve seat 26 is provided in the valve chamber 25. Specifically, the first inflow port 22 has an inlet portion 22a, an intermediate portion 22b, and an outlet portion 22c that are continuously formed in order from the upstream side. The inlet portion 22a is formed in a columnar shape, and the intermediate portion 22b is formed in a tapered shape in which the inner diameter increases toward the downstream side. The outlet portion 22c is formed in a columnar shape, and the inner diameter is formed larger than the inner diameter of the inlet portion 22a and smaller than the maximum inner diameter of the intermediate portion 22b. The inlet portion 22a, the intermediate portion 22b, and the outlet portion 22c are formed coaxially with each other, and their axes are the axes of the first inflow port 22. At the first inflow port 22, the outlet portion 22c opens into the valve chamber 25. An annular valve seat 26 coaxial with the outlet portion 22c (first inflow port 22) is formed at the inner edge portion of the outlet portion 22c (first inflow port 22) that opens into the valve chamber 25.

The valve body 30 has a shaft 31, a valve portion 32, a first impeller 41, and a second impeller 35. The shaft 31, the valve portion 32, and the two impellers 35 and 41 are integrally provided with each other.

The shaft 31 extends in the upstream / downstream direction (that is, in the vertical direction) of the drain discharge pipe 16 and is provided coaxially with the first inflow port 22. The upper end of the shaft 31 is supported by a support portion 27 provided in the upper portion of the valve chamber 26 in the casing 21. Specifically, the upper end of the shaft 31 is inserted into the insertion hole 27a provided in the support portion 27. The lower end of the shaft 31 is supported by a support 28 provided at the outlet 22c at the first inflow port 22. The support portion 28 is provided with a plurality of flow holes 28a through which fluid can flow (see FIGS. 4 and 5).

The valve portion 32 is a plate-shaped member formed in a disk shape (disk shape), and is provided coaxially with the shaft 31 in the middle of the shaft 31. That is, the valve portion 32 is formed in a disk shape whose axial center extends in the upstream / downstream direction (that is, the vertical direction) of the drain discharge pipe 16. The valve portion 32 is provided on the downstream side (upper side) of the first inflow port 22, and takes off and seats on the valve seat 26 to open and close the first inflow port 22 (outlet portion 22c).

The second impeller 35 has a main body 36 and blades 37, and is provided on a shaft 31. The second impeller 35 is provided with a gap 45 between the valve portion 32 and the valve portion 32 on the upstream side (below the valve portion 32) of the valve portion 32. The main body 36 is formed in a conical shape in which the top 38 is located on the upstream side and extends in the upstream and downstream directions. That is, the main body 36 is formed in a conical shape in which the outer diameter decreases toward the upstream side (downward). The main body 36 (second impeller 35) is provided coaxially with the shaft 31. A plurality of blades 37 are provided on the conical surface of the main body 36. The blade 37 is a linear member spirally extending from the top 38 of the cone toward the downstream side (upward), and the cross section perpendicular to the conical surface is formed in a quadrangular shape. The maximum outer diameter of the second impeller 35 is smaller than the inner diameter of the outlet portion 22c that opens into the valve chamber 25.

The first impeller 41 has a main body 42 and blades 43, and is provided on a shaft 31. The first impeller 41 is formed integrally with the valve portion 32 on the downstream side (above the valve portion 32) of the valve portion 32. The main body 42 is continuously formed on the downstream side surface (upper surface in FIG. 2) of the valve portion 32. The main body 42 is formed in a slightly flat truncated cone shape in which the outer diameter increases from the downstream side surface of the valve portion 32 toward the downstream side (upper side). The main body 42 (first impeller 41) is provided coaxially with the shaft 31. A plurality of blades 43 are provided on the conical surface of the main body 42. The blade 43 is a linear member that extends at an angle with respect to the ridgeline of the conical surface, and has a rectangular cross section perpendicular to the conical surface. The vertical cross section of the blades 37 and 43 with respect to the respective conical surfaces may be, for example, triangular or trapezoidal.

In this way, the second impeller 35, the valve portion 32, and the first impeller 41 are fixed to the shaft 31 in order from the upstream side (lower side), and these are coaxial with the shaft 31 (first inflow port 22). It is provided. The shaft 31 is provided so as to be rotatable around the axis and displaceable in the direction of the axis (the axial direction of the first inflow port 22). That is, the valve portion 32 and the two impellers 35, 41 are rotatably provided about the shaft 31, and are rotatably provided in the upstream / downstream direction (vertical direction) of the drain discharge pipe 16.

The valve portion 32 is configured to open and close the first inflow port 22 (outlet portion 22c) by being displaced in the upstream and downstream directions. That is, when the valve portion 32 is displaced to the upstream side and is seated on the valve seat 26, the first inflow port 22 is closed. When the valve portion 32 is displaced to the downstream side and is separated from the valve seat 26, the first inflow port 22 is opened. The valve portion 32 is urged to the upstream side (that is, the side that closes the first inflow port 22) by the weight of the valve portion 32, the shaft 31, the second impeller 35, and the first impeller 41. That is, the weight of the entire valve body 30 is used as an urging force for urging the valve portion 32 toward closing the first inflow port 22. The maximum outer diameter of the second impeller 35 is smaller than the outer diameter of the valve portion 32 and smaller than the minimum outer diameter of the first impeller 41.

As shown in FIG. 2, when the valve portion 32 is separated from the valve seat 26, the second impeller 35 is in a state of straddling the first inflow port 22 (outlet portion 22c) and the valve chamber 25. The entire first impeller 41 is always located in the valve chamber 25. The second impeller 35 constitutes a drive unit that rotationally drives the entire valve body 30 by receiving the pressure of the fluid flowing into the first inflow port 22. As the entire valve body 30 rotates, the first impeller 41 also rotates. The first impeller 41 is configured to diffuse the fluid outward by rotating. That is, the second impeller 35 is rotated by the steam flowing into the first inflow port 22. Then, the steam that has passed from the second impeller 35 to the gap 45 is diffused by the rotation of the first impeller 41. Further, the first impeller 41 is configured to rotate by the flow of drain from the second inlet 23 to the outlet 24. That is, the first impeller 41 constitutes a drive unit that rotationally drives the entire valve body 30 by contacting the drain flowing from the second inflow port 23 to the outflow port 24.

In the check valve 20 configured in this way, when the fluid pressure on the upstream side (drain discharge pipe 16 side) becomes higher than the fluid pressure on the downstream side (drain recovery pipe 14 side), the valve portion 32 (valve body 30). ) Displaces to the downstream side and leaves the seat, and the first inflow port 22 opens (state shown in FIG. 2). As a result, the flow of drain from the drain discharge pipe 16 to the drain recovery pipe 14 is allowed. Further, when the fluid pressure on the upstream side (drain discharge pipe 16 side) becomes lower than the fluid pressure on the downstream side (drain recovery pipe 14 side), the valve portion 32 (valve body 30) is displaced to the upstream side and seated. , The first inflow port 22 is closed (state shown in FIG. 6). Therefore, the flow (backflow) of the drain from the drain collection pipe 14 to the drain discharge pipe 16 is blocked. It is assumed that the above-mentioned fluid pressure on the downstream side includes the own weight of the entire valve body 30, which is an urging force.

By blocking the above-mentioned backflow by the check valve 20, it is possible to avoid a state in which the fluid pressure on the downstream side of the steam trap 17 rises and the drain operation of the steam trap 17 becomes difficult. Further, by blocking the above-mentioned backflow by the check valve 20, the generation of an impact (water hammer) in the steam trap 17 is suppressed.

That is, since not only drain but also high-temperature steam flows into the steam trap 17 from the steam supply pipe 11, a relatively large mass (space) of steam exists. If the above-mentioned backflow is allowed, low-temperature drain flows into the steam trap 17 from the drain recovery pipe 14. Then, in the steam trap 17, the steam comes into contact with the low-temperature drain and rapidly condenses, so that the space in which the steam existed becomes a vacuum state at once. Drains flow into the vacuum space at once, and the drains collide with each other or the drains collide with the inner surface of the casing of the steam trap 17, so that an impact (water hammer) is generated. According to this embodiment, the possibility of such a water hammer is avoided.

Next, a case where the check valve 20 is opened and the flow of drain from the drain discharge pipe 16 to the drain recovery pipe 14 is allowed will be described. The drain discharged from the steam trap 17 flows into the first inflow port 22 of the check valve 20. The drain that has flowed into the first inflow port 22 merges with the low-temperature drain of the drain recovery pipe 14 that has flowed in from the second inflow port 23 in the valve chamber 25, and flows out from the outflow port 24 to the drain recovery pipe 14. In this way, the drain generated in the steam supply pipe 11 is recovered.

A part of the drain discharged from the steam trap 17 may be re-evaporated into steam (flash steam). This is because the drain flowing into the steam trap 17 from the steam supply pipe 11 has a high temperature, and the high temperature drain is discharged from the steam trap 17 to reduce the pressure. The re-evaporated steam flows into the first inflow port 22 of the check valve 20.

In the check valve 20, the second impeller 35 rotates due to the steam flow flowing into the first inflow port 22. The steam flowing into the first inflow port 22 passes through the gap 45 from the second impeller 35, and then turns and diffuses by hitting the rotating first impeller 41. Further, when the drain flowing into the second inflow port 23 hits the first impeller 41, a rotational force is applied to the first impeller 41. The vapor is finely dispersed by being diffused. The dispersed steam flows into the valve chamber 25, merges with the low-temperature drain, and flows out from the outflow port 24 to the drain recovery pipe 14.

In this way, the steam is finely dispersed by the check valve 20 and flows to the drain recovery pipe 14, so that the impact (water hammer) generated in the drain recovery pipe 14 is suppressed. That is, when the steam flows into the drain recovery pipe 14 without being dispersed, a relatively large steam mass (space) is formed in the drain recovery pipe 14 as the steam flows in. This mass of steam is cooled by the low-temperature drain around it and rapidly condenses, so that the space in which the steam existed becomes a vacuum state at once. The surrounding drains flow into the vacuum space at once, and the drains collide with each other or the drains collide with the pipe wall of the drain recovery pipe 14, so that an impact (water hammer) is generated.

In the present embodiment, the steam is finely dispersed by the check valve 20 and flows into the drain recovery pipe 14, so that it becomes difficult for a large steam mass (space) to be formed in the drain recovery pipe 14. Therefore, the vacuum space generated by the rapid condensation of steam becomes small. Therefore, the generation of a large water hammer that causes noise and damage to the pipe is suppressed. That is, the size of the water hammer becomes smaller.

Further, the steam flowing from the lower first inflow port 22 to the valve chamber 25 floats due to the difference in density with the drain. Therefore, the contact area between the steam and the low-temperature drain increases, and the steam condensing action is promoted. Therefore, in the valve chamber 25, the vapor condenses and becomes a drain before a large vapor mass is formed. This also applies to the steam flowing through the drain recovery pipe 14.

As described above, the check valve 20 of the above embodiment has a valve chamber 25 that communicates with the first inflow port 22 of steam (first fluid), the outflow port 24, and the first inflow port 22 and the outflow port 24. The casing 21 is provided with a casing 21, a valve portion 32 provided in the valve chamber 25 for opening and closing the first inflow port 22, and a first impeller 41 provided in the casing 21 for diffusing steam. ..

According to the above configuration, the backflow of the drain can be prevented, while the inflowing steam can be swirled and diffused by the rotation of the first impeller 41. The vapor is finely dispersed by being diffused. Therefore, the steam can be finely dispersed and flowed into the drain recovery pipe 14 through which the low temperature drain flows. As a result, it is possible to suppress the formation of a large vapor mass (space) in the drain recovery pipe 14. Therefore, in the drain recovery pipe 14 on the downstream side of the check valve 20, it is possible to suppress the generation of water hammer due to the rapid condensation of steam lumps or reduce the size of the water hammer. Therefore, it is possible to suppress noise and pipe damage caused by the water hammer.

Further, the check valve 20 of the above embodiment is provided in the casing 21 coaxially with the first inflow port 22 and is rotatably provided, and includes a shaft 31 to which the first impeller 41 is coaxially fixed. .. Further, the check valve 20 includes a second impeller 35 that is coaxially fixed to a portion of the shaft 31 on the upstream side of the first impeller 41 and is rotated by the flow of steam (first fluid). According to this configuration, the second impeller 35 can be rotated by utilizing the flow of steam, and the first impeller 41 can be rotated along with the rotation of the second impeller 35.

Further, in the check valve 20 of the above embodiment, the axes of the first inflow port 22 and the outflow port 24 are orthogonal to each other, and the casing 21 communicates with the outflow port 24 via the valve chamber 25. Further, a second inflow port 23 of the low temperature drain (second fluid) of the drain recovery pipe 14 formed coaxially with the outflow port 24 is provided. The first impeller 41 is located in the valve chamber 25 and is configured to be rotatable by the flow of the low temperature drain. According to this configuration, the first impeller 41 can be rotated by utilizing the flow of the second fluid, that is, the flow of the drain of the drain recovery pipe 14 from the second inlet 23 to the outlet 24.

Further, in the check valve 20 of the above embodiment, when the valve portion 32 is separated from the valve seat 25, the second impeller 35 is positioned across the first inflow port 22 (outlet portion 22c) and the valve chamber 25. It is configured to do so. Therefore, the second impeller 35 also rotates when it is hit by the second fluid. Therefore, the second impeller 35 can be rotated not only by the flow of the first fluid but also by the flow of the second fluid.

Further, in the check valve 20 of the above embodiment, the valve portion 32 is formed in a disk shape coaxial with the first inflow port 22, and is between the first impeller 41 and the second impeller 35 on the shaft 31. It is fixed coaxially with. Further, in the check valve 20, the shaft 31 is first opened and closed so that the valve portion 32 is displaced in the axial direction of the first inflow port 22 and is detached and seated on the valve seat 26 to open and close the first inflow port 22. It is provided so as to be freely displaceable in the axial direction of the inflow port 22.

According to the above configuration, when the valve portion 32 is separated from the valve seat 26, a gap is formed on the outer peripheral side of the valve portion 32, and the fluid flows from the gap to the downstream side. On the other hand, the first fluid tends to flow toward the outer peripheral side due to the rotation of the second impeller 35, so that the first fluid smoothly flows out from the gap between the valve portion 32 and the valve seat 26. Thereby, the flow resistance in the check valve 20 can be relaxed.

In particular, the second impeller 35 includes a main body 36 having a top 38 located on the upstream side and extending in the axial direction of the first inflow port 22, and blades 37 provided on the conical surface of the main body 36. have. Therefore, the first fluid becomes an annular flow that flows toward the outer peripheral side of the valve portion 32 by the second impeller 35. Therefore, the first fluid can flow out from the gap between the valve portion 32 and the valve seat 26 more smoothly.

Further, in the check valve 20 of the above embodiment, the second impeller 35 and the valve portion 32 are provided with a gap 45 between them. According to this configuration, the second fluid flowing in from the second inflow port 23 flows to the outflow port 24 through not only the downstream side (upper side) region of the first impeller 41 but also the upstream side (gap 45) region. .. Therefore, the stagnation of the flow of the second fluid caused by the second fluid hitting the first impeller 41 or the second impeller 35 can be alleviated. That is, the flow of the second fluid toward the first impeller 41 or the second impeller 35 can be activated. Thereby, the force for rotating the first impeller 41 or the second impeller 35 can be further obtained. Therefore, the vapor can be more diffused.

Further, in the check valve 20 of the above embodiment, the first impeller 41 is formed continuously on the downstream side surface of the valve portion 32, and has a truncated cone shape in which the outer diameter increases from the downstream side surface to the downstream side. It has a formed main body 42 and blades 43 provided on the conical surface of the main body 42. According to this configuration, the steam swirled by the second impeller 35 can be swirled more by the rotation of the first impeller 41. Therefore, the vapor can be more diffused.

Further, in the check valve 20 of the above embodiment, the axis of the first inflow port 22 extends in the vertical direction and is provided below the valve chamber 25. Further, the valve portion 32 is urged toward closing the first inflow port 22 by the weight of the valve portion 32, the shaft 31, the first impeller 41 and the second impeller 35. Therefore, it is not necessary to separately provide an urging member.

(Other embodiments)
The technique disclosed in the present application may have the following configuration in the above embodiment. For example, in the above embodiment, the first impeller 41 is integrally formed with the valve portion 32, but the first impeller 41 and the valve portion 32 may be provided with a gap between them.

Further, the first impeller 41 is not limited to the form described in the above embodiment, and may be any form as long as the fluid can be diffused by rotating. The second impeller 35 is not limited to the form described in the above embodiment, and may be in any form as long as it can be rotated by the flow of the first fluid or the second fluid. For example, the second impeller 35 may be formed in a truncated cone shape, and the first impeller 41 may be formed in a columnar shape.

Further, in the check valve 20 of the above embodiment, the second impeller 35 may be omitted. In this case, the first impeller 41 is rotated by the flow of the second fluid (drain) flowing in from the second inflow port 23. Then, the steam is swirled and diffused by the rotation of the first impeller 41.

Further, in the check valve 20 of the above embodiment, steam is exemplified as the fluid to be diffused, but the technique disclosed in the present application is not limited to this, and any gas that causes water hammer by rapid condensation is used. Anything may be targeted.

The techniques disclosed in this application are useful for check valves.

20 Check valve 21 Casing 22 1st inflow port 23 2nd inflow port 24 Outlet 25 Valve chamber 26 Valve seat 31 Shaft 32 Valve part 35 2nd impeller 36 Main body 37 Blade 38 Top 41 1st impeller 42 Main body 43 45 gap

Claims (7)

A casing formed with a first inlet and outlet of the first fluid, and a valve chamber communicating with the first inlet and outlet.
A valve portion provided in the valve chamber to open and close the first inflow port,
A first impeller provided in the casing and diffusing the first fluid ,
A shaft provided in the casing coaxially with the first inflow port and rotatably provided, and the first impeller is coaxially fixed.
A check valve comprising a second impeller that is coaxially fixed to a portion of the shaft upstream of the first impeller and that rotates by the flow of the first fluid. .. In the check valve according to claim 1,
The axes of the first inlet and outlet are orthogonal to each other.
The casing is provided with a second inflow port for a second fluid that communicates with the outflow port via the valve chamber and is formed coaxially with the outflow port.
The first impeller is a check valve located in the valve chamber and rotatably configured by the flow of the second fluid. In the check valve according to claim 1 or 2.
An annular valve seat is formed at the inner edge of the first inflow port.
The valve portion is formed in a disk shape coaxial with the first inflow port, and is coaxially fixed between the first impeller and the second impeller on the shaft.
The shaft is oriented in the axial direction of the first inflow port so that the valve portion opens and closes the first inflow port by being displaced in the axial direction of the first inflow port and taking off and seating on the valve seat. A check valve characterized by being freely displaceable. In the check valve according to claim 3,
The first impeller is integrally formed on the downstream side surface of the valve portion.
A check valve characterized in that the second impeller and the valve portion are provided with a gap between them. In the check valve according to claim 3 or 4.
The second impeller has a main body having a top located on the upstream side and extending in the axial direction of the first inflow port, and blades provided on the conical surface of the main body. A check valve characterized by that. In the check valve according to claim 4,
The first impeller is formed on a truncated cone-shaped main body that is continuously formed on the downstream side surface of the valve portion and whose outer diameter increases from the downstream side surface to the downstream side, and on the conical surface of the main body. A check valve characterized by having provided blades. In the check valve according to any one of claims 3 to 6.
The first inflow port has an axial center extending in the vertical direction and is provided below the valve chamber.
The check valve is characterized in that the valve portion is urged toward closing the first inflow port by the weight of the valve portion, the shaft, the first impeller, and the second impeller.

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