JP2020026875A - Check valve - Google Patents

Abstract

To provide a check valve for avoiding the flow of fluid from being blocked when clogging occurs in filtering means such as a strainer.SOLUTION: When vapor or drain flows into a valve chest 5 of a check valve 10 along a forward direction 91, the vapor or the drin permeates through a strainer 2 and passes through the valve chest 5 while pushing a valve element 4 up in the direction of an arrow 95. When foreign matters are adhered onto the strainer 2 to cause clogging, the strainer 2 is opened around a shaft 24 in the direction of the arrow 95 similarly to the valve element 4 to allow the flow of the vapor or the drain in the forward direction 91. When the vapor or drain flows back into the valve chest 5, th valve element 4 and the strainer 2 are closed in the direction of the arrow 96 to function as the check valve. One end of the shaft 24 is exposed to the outside of the check valve 10, and a rotary indicator panel integrally fixed to one end of the shaft 24 is rotated for performing clogging alarming to promote maintenance work.SELECTED DRAWING: Figure 1

Description

  The check valve according to the present application relates to a check valve technology having a filtering means such as a strainer for capturing foreign matter in a fluid.

  The check valve is a valve provided in the fluid flow path and having a mechanism for preventing backflow of the fluid due to back pressure. For example, a pipe installed in an industrial plant transfers high-temperature and high-pressure steam, and a drain (condensed water) generated from the steam flows in this pipe in a predetermined direction (forward direction).

  In order to prevent such a backflow of steam or drain, a check valve is provided at a necessary position on the pipe. There are various types of check valves, such as a swing check valve, a lift check valve, and a spring disc check valve.

  By the way, foreign matter such as rust and scale (scale) is often mixed in the flow of steam or drain, and when steam or drain is transferred in a state where excessive foreign matter is generated, it is installed on the flow path. May adversely affect various types of devices. For this reason, a strainer for filtering foreign substances is often provided in the flow path.

  As such a check valve with a strainer, there is a technique disclosed in Patent Document 1 described below. The check valve disclosed in Patent Document 1 is a swing check valve, and a strainer is disposed inside a valve body that opens and closes. The valve element that opens and closes is provided so as to be able to contact the strainer.

  With such a configuration, in the technology disclosed in Patent Literature 1, it is possible to save space for installing the valve element and the strainer. In addition, when the valve element changes from the open state to the closed state, impact or vibration is transmitted to the strainer due to contact with the strainer, and foreign matter attached to the filtration member of the strainer can be shaken off.

JP 2009-228737 A

  However, in the check valve disclosed in Patent Document 1, when foreign matter is firmly attached to the filtration member of the strainer, the impact or vibration caused by the change of the valve body from the open state to the closed state is caused by the strainer. However, it is difficult to reliably remove foreign matter even if it is added. For this reason, maintenance work for removing foreign matter from the strainer is required, but in practice, frequent maintenance work cannot be performed.

  Therefore, when the strainer is clogged, there is a problem that the forward flow of the fluid is blocked by the clogged strainer until the maintenance work is performed. In particular, in a piping system for transferring high-temperature and high-pressure steam, if the forward flow of the steam and the like is stopped even for a short period of time, failure or breakage of each device occurs and serious problems occur. There is a danger of causing a situation.

  Therefore, a check valve according to the present application has an object to solve these problems, and even when clogging occurs in a filtration unit such as a strainer, a check flow that does not hinder the flow of fluid is provided. The purpose is to provide a valve.

  The check valve according to the present application is:

  A check valve arranged on a flow path through which a fluid flows to allow a flow of a fluid in a forward direction flowing from an inlet side to an outlet side and prevent a flow of a fluid in a reverse direction flowing from the outlet side to the inlet side. A valve means that is openably and closably opened and closed by receiving a flow of a fluid to allow a flow of a fluid in a forward direction, and closed by receiving a flow of a fluid in a reverse direction and closed by receiving a flow of a fluid in a reverse direction. Valve means for blocking flow, a filter means for opening and closing the inlet side to the valve means and capturing foreign matter in the fluid, which normally allows the flow of the fluid by allowing the fluid to pass therethrough. When clogging is caused by accumulation of foreign matter, a filter is provided that receives the forward flow of the fluid and opens to allow the flow of the forward fluid.

  In the check valve according to the present invention, when clogging is caused by accumulation of foreign matter, the filtering means receives the forward flow of the fluid and opens to allow the flow of the forward fluid. Therefore, even when the filtering means is clogged, the flow of the fluid is not blocked.

It is sectional drawing which shows 1st Embodiment of the non-return valve which concerns on this application, and is a cross-sectional view which shows the state (normal time) in which the flow in the forward direction occurs in a non-return valve. FIG. 2 is a cross-sectional view showing a state (normal operation) in which a check valve shown in FIG. 1 has a flow in a reverse direction. FIG. 3 is an external view of a check valve in a normal state of FIGS. 1 and 2. FIG. 2 is a cross-sectional view showing a state in which a forward flow is generated in the check valve shown in FIG. 1 (at the time of clogging). FIG. 5 is an external view of a check valve at the time of clogging in FIG. 4.

The main terms shown in the embodiments respectively correspond to the following elements of the check valve according to the present application.
Strainer 2 ・ ・ ・ Filtering means Valve 4 ・ ・ ・ Valve means Rotation display panel 6 ・ ・ ・ Interlocking notification means Inlet 10a ・ ・ ・ Inlet side Outlet 10b ・ ・ ・ Outlet side Shaft 24 ・ ・ ・ First rotating shaft, No. Dual rotating shaft Auxiliary strainer 29 ・ ・ ・ Auxiliary filtration means Steam or drain ・ ・ ・ Fluid Piping path ・ ・ ・ Flow path

[First Embodiment]
A first embodiment of a check valve according to the present application will be described with reference to the drawings. In the present embodiment, a swing check valve provided in a piping system arranged in an industrial plant will be described as an example. This piping system transfers high-temperature and high-pressure steam, and drain generated from the steam flows in the piping together with the steam.

(Overall configuration of check valve 10)
FIG. 1 shows a check valve 10 according to the present embodiment. The check valve 10 according to the present embodiment includes a main body 12, a main body lid 14 is fixed to a lid flange 12c located at an upper portion of the main body 12, and a valve chamber 5 is formed by the main body 12 and the main body lid 14. In the main body 12, an inlet 10a and an outlet 10b are formed so as to be located on the same straight line, and a pipe (not shown) is connected and fixed to the inlet flange 12a and the outlet flange 12b provided respectively. The steam and the drain pass through the valve chamber 5 along the forward direction 91 from the inlet 10a to the outlet 10b.

  The strainer 2 is provided in the valve chamber 5. The strainer 2 according to the present embodiment is disposed so as to be rotatable about the shaft 24 in directions indicated by arrows 95 and 96. The strainer 2 has a mesh part 22 formed over the whole, and the mesh part 22 captures steam and foreign matters in drain.

  The strainer 2 and the shaft 24 are integrally formed, and the shaft 24 is supported by a support hole (not shown) formed in the main body 12, and the strainer 2 is rotatably held. Since the strainer 2 and the shaft 24 are integrally formed, when the strainer 2 rotates in the direction of the arrow 95 or the arrow 96, the shaft 24 simultaneously performs a rotating operation in accordance therewith.

  One end of the shaft 24 penetrates through a support hole of the main body 12 through a packing and is exposed to the outside, and a circular rotary display panel 6 is integrally fixed to the exposed end face as shown in FIG. I have. FIG. 3 is an external view as viewed from the same direction as FIG. Since the rotary display panel 6 is integrally fixed to one end of the shaft 24, the rotation of the strainer 2 is transmitted to the rotary display panel 6 via the shaft 24, and the rotary display panel 6 interlocks with the strainer 2. Rotate. In the present embodiment, a triangular instruction mark is provided on the rotary display panel 6. On the other hand, on the outer surface of the check valve, a normal mark 61 and a clogging mark 62 are displayed near the periphery of the rotary display panel 6.

  A valve seat 16 protruding inward is provided on the bottom surface of the valve chamber 5. When the strainer tip 2G of the strainer 2 abuts on the valve seat 16, the rotation of the strainer 2 in the direction of arrow 96 is restricted.

  Further, the valve element 4 is rotatably attached to the shaft 24 of the strainer 2. By connecting the connecting portion (not shown) of the valve element 4 to the shaft 24, the valve element 4 can rotate independently to the arrows 95 and 96 independently of the rotation of the strainer 2. Note that a ceiling surface 19 is provided in an upper part of the valve chamber 5 so as to protrude.

  In the present embodiment, an auxiliary strainer 29 is arranged in the piping system on the downstream side (in the direction of the outlet) of the check valve 10. The auxiliary strainer 29 is detachable during maintenance, but is fixed to the piping system except during maintenance.

(Explanation of the operation of the check valve 10 under normal conditions)
Next, the operation of the check valve 10 in a normal state (when the strainer 2 is not clogged) will be described. Steam and drain flow into the valve chamber 5 of the check valve 10 from the inlet 10a along the forward direction 91 through the connected pipe. Then, the steam and the drain pass through the mesh portion 22 of the strainer 2 and apply a fluid pressure to the valve element 4.

  Upon receiving this fluid pressure, the valve element 4 is turned in the direction of the arrow 95 and flipped up, and as shown in FIG. By opening the valve element 4, the flow of steam or drain in the forward direction 91 is allowed, and the steam or drain passes through the valve chamber 5 and flows out to the outlet pipe connected through the outlet 10b. The outflowing steam and drain further pass through the auxiliary strainer 29 and travel along the piping system.

  When the steam or the drain receives the back pressure and flows back to the valve chamber 5 of the check valve 10 along the reverse direction 92 as shown in FIG. 2, the valve element 4 reduces the fluid pressure of the backflowing steam or the drain. Then, it rotates in the direction of arrow 96, and comes into contact with the strainer 2 to close the valve. By closing the valve body 4, the flow of steam and drain in the reverse direction 92 is prevented, and the function as a check valve is achieved.

  Note that the strainer 2 is in the closed position shown in FIG. 1 and FIG. 2 both in the case where the flow of the steam and the drain is in the forward direction 91 and in the case where the flow is in the reverse direction 92. For this reason, in the normal state where the strainer 2 is not clogged, the indication mark on the rotary display panel 6 is located in a state pointing to the normal mark 61 as shown in FIG.

(Explanation of operation of check valve 10 at the time of clogging)
Next, the operation of the check valve 10 when the strainer 2 is clogged will be described. As described above, the strainer 2 captures foreign matter in steam and drain, and captures foreign matter larger than the mesh of the mesh part 22 by allowing the steam and drain to pass through the mesh part 22.

  The captured foreign matter adheres to the mesh portion 22 of the strainer 2 and gradually accumulates. The state in which the mesh portion 22 is completely closed by the foreign matter and cannot pass through the vapor or the drain is the state of clogging.

  When the clogged strainer 2 receives the flow of steam or drain in the forward direction 91, the strainer 2 receives the fluid pressure, and the strainer 2 opens in the direction of arrow 95 around the shaft 24 as shown in FIG. become. At this time, rotation of the strainer 2 in the direction of the arrow 95 is regulated by the contact of the strainer tip 2G of the strainer 2 with the ceiling surface 19 above the valve chamber 5.

  In this way, due to the clogging of the strainer 2, the strainer 2 performs the same operation as the valve body 4, and despite the clogging, the flow of steam and drain in the forward direction 91 is reduced. It is allowed without being stopped. In this case, the auxiliary strainer 29 captures the steam flowing in the forward direction 91 and foreign matters in the drain.

  When the steam or the drain receives the back pressure and flows backward to the valve chamber 5 along the reverse direction 92, the valve body 4 and the strainer 2 receive the fluid pressure of the backward flowing steam or the drain, and the valve body 4 and the strainer 2 Pivots in the direction of arrow 96, and is in the same state as in FIG. By closing the valve body 4 and the strainer 2, the flow of steam and drain in the reverse direction 92 is prevented, and the function as a check valve is achieved.

  Here, as described above, since the strainer 2 and the shaft 24 are integrally formed, when the strainer 2 in which the clogging has occurred is opened in the direction of the arrow 95 (in the state of FIG. 4), the shaft 24 is also in the same state. Will rotate. Then, the rotary display panel 6 fixed to the shaft 24 also rotates integrally, and the indication mark of the rotary display panel 6 is moved from the position indicating the normal mark 61 (FIG. 3) to the clogging mark as shown in FIG. It switches to the position pointing to 62. When the instruction mark on the rotary display panel 6 points to the clogging mark 62, it is notified that the strainer 2 has been opened in the direction of the arrow 95 due to clogging, and the maintenance work is encouraged.

  For this reason, clogging of the strainer 2 can be easily and reliably recognized from the outside, and the operator can perform maintenance work early. Specifically, the worker removes the main body cover 14 from the main body 12 and performs a cleaning operation for removing foreign substances attached to the mesh portion 22 of the strainer 2 and the like. At the same time, the auxiliary strainer 29 is also taken out from the piping system, and the auxiliary strainer 29 is also cleaned.

[Other Embodiments]
In the above-described embodiment, an example in which the check valve according to the present application is applied to the swing type check valve 10 is described, but the present invention can also be applied to a type of check valve other than the swing type.

  For example, a spring disc check valve has a disc as a valve body that is biased by a spring in a valve chamber of the check valve, and when fluid flows in a forward direction, the disc compresses the spring. A structure is provided that allows the fluid to flow in parallel. The check valve according to the present invention is applied to such a spring disk check valve, and a strainer is arranged via a spring inside the disk. If the strainer is clogged, the strainer receives the fluid pressure of the fluid and receives the fluid pressure. Similarly to the above, if the valve opening operation is performed by the parallel movement, even if the strainer is clogged, the flow of the fluid is not obstructed.

  That is, when the strainer (filter means) provided in the valve chamber of the check valve is clogged, the strainer receives a flow of a fluid such as steam or drain, and performs the same movement as the valve body (valve means). With such a configuration, the check valve according to the present application can be applied to a check valve of a type other than the swing check valve exemplified in the above-described embodiment.

  Further, in the above-described embodiment, the valve element 4 is illustrated as the valve means, and the strainer 2 is illustrated as the filtering means, but other shapes and structures may be adopted.

  Furthermore, in the above-described embodiment, the rotation display panel 6 (interlocking notification means) and the normal mark 61 and the clogging mark 52 have been exemplified, but they operate in conjunction with opening and closing of the strainer (filtering means), and the strainer is opened. Other shapes and structures may be adopted as long as the information is notified so that the fact can be recognized from the outside. For example, it is also possible to generate an electric signal in accordance with the rotation of the strainer, receive the signal in a wired or wireless manner, and display and notify information on clogging on a monitor or the like.

  Further, in the above-described embodiment, the first rotary shaft for rotating the valve means and the second rotary shaft for rotating the filtering means are shared by the same shaft 24 to save space. However, a separate rotation axis can be provided.

2: Strainer 4: Valve body 6: Rotation display panel 10a: Inlet 10b: Outlet
24: Axis 29: Auxiliary strainer

Claims (4)

A check valve arranged on a flow path through which a fluid flows to allow a flow of a fluid in a forward direction flowing from an inlet side to an outlet side and prevent a flow of a fluid in a reverse direction flowing from the outlet side to the inlet side. ,
A valve means which is openably and closably opened and closed by receiving a flow of a fluid to allow a flow of a fluid in a forward direction, and closed by receiving a flow of a fluid in a reverse direction and closed by receiving a flow of a fluid in a reverse direction. Valve means for blocking
Filtering means which is openably and closably disposed on the inlet side to the valve means and traps foreign matter in the fluid. Normally, the fluid is allowed to flow by allowing the fluid to permeate, and clogging due to accumulation of foreign matter is achieved. At the time, a filter means that receives the forward flow of the fluid and opens to allow the flow of the forward fluid,
A check valve comprising: A check valve arranged on a flow path through which a fluid flows to allow a flow of a fluid in a forward direction flowing from an inlet side to an outlet side and prevent a flow of a fluid in a reverse direction flowing from the outlet side to the inlet side. ,
Valve means which is openable and closable by rotating about a first rotation axis. The valve means receives a flow of a fluid, and opens and rotates to allow a flow of a fluid in a forward direction. Valve means for receiving the flow in the direction, rotating and closing to prevent the flow of the fluid in the opposite direction,
At the inlet side to the valve means, it is a filter means which is openably and closably positioned by rotating about the second rotation axis and captures foreign matter in the fluid. Filter means for receiving the forward flow of the fluid, rotating and opening, and allowing the flow of the forward fluid,
A check valve comprising: In the check valve according to claim 1 or 2,
Interlocking notifying means that operates in conjunction with opening and closing of the filtering means, and notifies that the filtering means has been opened so that it can be recognized from the outside;
A check valve comprising: In the check valve according to claim 1 or 2,
Auxiliary filtration means is provided on the outlet side with respect to the valve means,
Non-return valve characterized by the above-mentioned.

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