JPH0222269B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of cleaning a butterfly valve and a butterfly valve adapted to carry out this cleaning method.

[Conventional technology]

Butterfly valves have comb-like protrusions formed on the front and back peripheral edges of the valve body for the purpose of reducing the effects of cavitation. Fluid is allowed to flow through the gaps, but solid matter such as dirt mixed in the flowing fluid is likely to get caught in the comb-shaped protrusions. It is difficult to automatically remove trapped dirt and other solid objects by simply rotating the range from the closed position to the fully open position, especially when the width of the groove-like gap is narrow. Once solid matter such as garbage gets stuck in the deep part of the valve, the butterfly valve, along with the valve box, must be removed from the pipe line and the valve body must be cleaned.

[Problem that the invention seeks to solve]

However, it is not possible to confirm from outside the valve box whether solid objects such as garbage are caught on the comb-like protrusions of the valve body. If this butterfly valve is used in its current condition, solid matter such as dirt may become trapped between the valve body and the valve seat, making it impossible to completely close the valve body, or causing the valve body to close completely. There was a risk of damaging the peripheral seal and the valve seat on the valve body side. Further, when the valve body is periodically cleaned, it is time-consuming to remove the valve box interposed in the conduit, and there are also problems such as the need to temporarily cut off fluid flow.

The present invention has been developed in view of the above problems, and it is possible to remove dirt and the like caught in the comb-shaped protrusions of the valve body without interrupting the flow of fluid while the valve body remains in the pipeline. The purpose of the present invention is to provide a method for cleaning a butterfly valve that can be easily carried out, and a butterfly valve adapted to carry out this cleaning method.

[Means for solving problems]

As a means for solving the above problems, the method of the first invention removes fixed objects such as dirt caught in the comb-like projections of a butterfly valve having comb-like projections on the front and back peripheral edges of the valve body. In a method for cleaning butterfly valves, a valve body supported by a valve stem and rotatably disposed in a valve box is rotated from a fully closed position in an open direction beyond a fully open position. The butterfly valve of the second invention is characterized in that the butterfly valve of the second invention is further rotated in the rotational direction to clean dirt, etc. caught in the comb-like protrusions by the fluid flowing through the piping. In a butterfly valve having a comb-like protrusion, the valve body is supported by a valve stem and rotatably disposed in a valve box, and the valve body is fully closed via the valve stem. It has a reducer that can rotate from the fully open state to the open direction, and a function to stop the rotating valve body at the fully closed position and the fully open position.
It is characterized by being equipped with a stopper device whose function of stopping the rotation can be released from the outside.

[Effect]

By rotating the valve body beyond the fully open position,
The protruding direction of the comb-like protrusions formed on the valve body is reversed, and the dirt, etc. caught on the comb-teeth-like protrusions is removed by the action of the circulating fluid, and the valve body is automatically cleaned. .

〔Example〕

Hereinafter, a method for cleaning a butterfly valve according to the present invention and a butterfly valve adapted to carry out this cleaning method will be described.

A comb tooth-like protrusion is formed in an arc shape along the periphery on the front and back sides of a disk-shaped valve body that is rotatably arranged in a valve body and supported by a valve stem, and is generated and grows during opening and closing operations. In a butterfly valve designed to suppress cavitation, solid objects such as dirt are likely to get caught in the comb-like protrusions, and there is a risk that the effect of suppressing cavitation may be impaired by the caught solid objects such as dirt. Therefore, the first invention is a method for cleaning solid matter such as dirt caught on the comb-like protrusions by using a fluid flowing through the pipe while the butterfly valve remains installed on the pipe. In this butterfly valve cleaning method, first, the valve body, which is supported on a valve stem and rotatably arranged in a valve box, is moved from a fully closed position to an open direction beyond the fully open position for the same number of times. The valve body is further rotated in the direction of movement to set the valve body in a substantially inverted cleaning position. When the valve body is reversed and set in this cleaning position, the protruding direction of the comb-like protrusions is opposite to that during normal valve operation, and solid matter such as dirt caught on the comb-teeth-like protrusions is removed. It is removed by the action of the fluid and cleaning is performed automatically.

Next, an embodiment of a butterfly valve according to a second invention, which is a butterfly valve capable of carrying out the cleaning method of the first invention, will be described with reference to the drawings.

1 to 3 show the structure of a butterfly valve according to the present invention, in which a butterfly valve 1 has a substantially disk-shaped valve body 2 supported on a valve stem 3 and rotated into a cylindrical valve body 4. It is movable. The valve stem 3 extends upward from the valve body 4 in a liquid-tight manner, and is placed on the upper part of the valve body 4 to restrict the range of rotation of the valve stem 3 and move the valve body 2 to a fully closed position and a fully open position. It extends through the position-defining stop device 5 into the reduction gear 6 above the stop device 5 .

The speed reducer 6 is a speed reducer that can move the valve body 2 from the fully closed position to the open direction, pass through the fully open position, and further rotate in the same direction. The end of the valve stem 3 is engaged with the end of the valve stem 3, and the input shaft 7 is gear-engaged with the input side of the reduction gear, and the handle 8 attached to the input shaft 7 or the electric actuator 9 The valve rod 3 is driven at a deceleration speed to open and close the valve body 2 by rotating it manually or electrically by an electric motor 9a.

Further, the entire inner peripheral surface of the cylindrical valve box 4 is covered with a rubber valve seat 10.
0 performs shaft sealing of the portion of the valve stem 3 that penetrates the valve body 4, and an annular seal portion 2a formed in an oval shape on the periphery of the valve body 2 seals the rubber valve seat 10.
The valve closes by contacting the valve in a slightly inclined state (approximately 15° from the right angle), blocking the flow of fluid flowing in the direction of the arrow, and in a direction in which the seal portion 2a is separated from the rubber valve seat 10. The valve is rotated to open and allow fluid to flow.

On the front and back sides of the valve body 2, a comb-like protrusion 11 is provided on the side surface facing upstream when the valve body 2 is closed, and at the peripheral edge of a semicircular portion 2b that moves to the upstream side when the valve is opened. , comb teeth-like protrusions 12 are each formed in an arc shape on the peripheral edge of a semicircular portion 2C that faces downstream when the valve is closed and moves toward the downstream side when the valve is opened;
Groove-shaped gaps 11b and 12b are formed between the protrusions 11a and 11a and between the comb-like protrusions 11 and 12, respectively, and between the protrusions 12a and 12a.

On the other hand, the rotation range of the valve stem 3 is restricted, and the valve body 2 is moved from the fully closed position to the fully open position (from the fully closed position to the open direction).
The stopper device 5, which defines a position rotated by 75 degrees, is pivoted on a cylindrical casing 13 having a semi-cylindrical cross section and the valve stem 3 that passes through the cylindrical casing 13. A fan-shaped stopper 14 with an arc of 105° is provided.

The stopper 14 is connected to the cylindrical casing 13.
The valve rod 3 is screwed into a screw hole drilled in a planar side wall portion in a direction perpendicular to the valve rod 3, and the distal end side is inserted into the cylindrical casing 13, and the proximal end side is inserted into the cylindrical casing 13.
a fully closed position stopper bolt 15 disposed outside of the valve body 2, whose tip contacts one side of the fan-shaped stopper 14 when the valve body 2 is fully closed to restrict rotation of the valve stem 3 in the valve closing direction; A fully open position stopper bolt 16 is provided, the tip of which comes into contact with the other side of the fan-shaped stopper 14 when the valve body 2 is fully opened, thereby restricting rotation of the valve body 2 in the valve opening direction.

A stopper 14 is pivotally attached to the valve stem 3.
is fixed by a key 14a so as to rotate integrally with the valve stem 3, and both stopper bolts 15,
16 is a cylindrical casing 13 by rotating.
A lock nut 17 is attached to the outer portion of the cylindrical casing 13 of both stopper bolts 15, 16 so as to be able to adjust the extension length thereof, and fixes both stopper bolts 15, 16 with a predetermined extension length, respectively. 17 are screwed together.

Next, the operation of this embodiment configured as described above will be explained based on FIGS. 4 to 7.

Butterfly valve 1 installed in a conduit (not shown)
The seal portion 2a formed on the peripheral edge of the valve body 2 is brought into contact with the rubber valve seat 10 provided on the inner peripheral surface of the valve body 4,
The flow of fluid is cut off, resulting in a fully closed state (see FIG. 4).

At this time, the stopper device 5 prevents the rubber valve seat 10 from coming into contact with the rubber valve seat 10 with an unnecessarily large force due to one side of the stopper 14 coming into contact with the tip of the stopper bolt 15 in the fully closed position. 10, and by rotating the fully closed position stopper bolt 15 after loosening the lock nut 17 and adjusting the length of extension into the cylindrical casing 13, the fully closed position stopper bolt 15 can be adjusted according to the pressure of the fluid to be controlled. The seal can be adjusted to withstand pressure.

Also, the period from immediately after rotating the valve stem 3 and operating the valve body 2 from the fully closed state to the fully open state, and from the fully open state to immediately before the valve operating to close the valve to the fully closed state. When a small flow rate flows between, that is, valve body 2
In the small opening range (see FIG. 5), the fluid flowing in the direction of the arrow between the periphery of the valve body 2 and the rubber valve seat 10 of the valve body 4 is formed at the periphery of the valve body 2. Groove-like gaps 11b, 1 between the comb-like protrusions 11, 12
2b.

At this time, the fluid flowing down in the direction of the arrow is converted into a plurality of jet jets when passing through the narrowly formed groove-like gaps 11b and 12b, and the cavitation generation position is moved away from the valve body downstream side, and cavitation is generated. By dispersing the positions, the growth of cavitation that occurs can be greatly suppressed.

Furthermore, depending on the type of fluid controlled by this butterfly valve 1, solid matter such as dirt may be mixed in the fluid, and the periphery of the valve body 2 may Solid matter in the fluid flowing through the plurality of groove-like gaps 11b, 12b formed in each of the comb-teeth-like protrusions 11, 12 provided in the portion is likely to be caught by the comb-teeth-like protrusions 11, 12, and especially In the small opening range of the valve body 2, there is a possibility that the plurality of protrusions 11a may be caught on the comb-like protrusions 11, each of which protrudes toward the upstream side.

If solid matter gets caught in the comb teeth 11, 12, the flow characteristics of the butterfly valve 1 will be impaired, the effect of suppressing the growth of cavitation will be reduced, and the comb teeth 11, 12 If the valve body 2 is opened or closed with solid objects caught on the rubber valve seat 10, there is a risk of damaging the rubber valve seat 10. Things need to be removed early.

Furthermore, by rotating the valve stem 3, the valve body 2 is opened approximately 75 degrees from the fully closed position to the fully open position (see Fig. 6). 2 is substantially parallel to the fluid flow direction, and each of the groove-like gaps 11b, 12b of both the comb-teeth-shaped protrusions 11, 12 of the valve body 2 opens substantially in the fluid flow direction, resulting in a loss of water head. becomes smaller.

At this time, the stopper device 5 has the stopper bolt 16 in the fully open position on another side of the fan-shaped stopper 14.
By contacting the tip of the valve body 2, the valve body 2 is stopped at the fully open position, and the fully open position stopper bolt 16 is rotated after loosening the lock nut 17 to adjust the extension length into the cylindrical casing 13. By doing so, the opening degree of the valve body 2 when fully opened can be changed and the maximum flow rate can be adjusted.

The butterfly valve 1 according to the present invention controls the fluid flowing through the pipeline as described above, and suppresses the occurrence and growth of cavitation especially in the small opening range of the valve body 2. Solid objects such as dirt are likely to get caught in the comb-like protrusions 11 and 12 of the body 2, and once the solid objects are caught in the comb-like protrusions 11 and 12, the valve body 2 should be moved within the range from the fully open position to the fully closed position. If the valve body 2 is opened and closed only by opening and closing, it will not be automatically removed due to the action of the flowing fluid. For example, even if the valve body 2 is fully opened (see FIG.
Since each of the protrusions 11b and 12b of 2 only protrudes in a direction substantially perpendicular to the fluid flow direction, it is difficult to expect much automatic cleaning of the valve body 2 in this state.

Therefore, in this butterfly valve 1, the valve body 2 is rotated from the fully closed position by 75 degrees in the valve opening direction, and then further rotated in the same rotation direction to move the valve body 2 from the fully closed state. The butterfly valve 1 can be rotated almost to an inverted state, and the butterfly valve 1 can be cleaned by flowing fluid.The cleaning method for this butterfly valve 1 will be explained next.

To clean the butterfly valve 1, first, the stopper 14 provided in the cylindrical casing 13 of the stopper device 5 is cleaned.
After loosening the lock nut 17, the fully open position stopper bolt 16, which stops the valve body 2 in the fully open position by restricting the rotation of the valve stem 3 by contacting the tip thereof with the bolt 17, is rotated and removed. The extension length into the cylindrical casing 13 is thereby shortened, and the restriction on rotation of the stopper 14 in the opening operation direction is released.

Next, the valve stem 3 is rotated to further rotate the valve body 2 in the same direction beyond the fully open position, and each of the comb-like protrusions 11 that have been protruding upstream in the small opening area of the valve body 2 is rotated. The protrusion 11b is made to protrude downstream, and the seal portion 2a is formed on the peripheral edge of the valve body 2.
is not in contact with the rubber valve seat 10 on the inner circumference of the valve body 4, and the fluid flows through the gap formed between the circumferential edge of the valve body 2 and the inner circumferential surface of the valve body 4, i.e. Rotate the valve body 2 to the cleaning position (see FIG. 7).

When the valve body 2 is placed in the cleaning position, the valve body 2 is in a tilted state with respect to the fluid flow direction, and the peripheral edge of the semicircular portion 2c of the valve body 2 forming the comb-like protrusions 12 on the upstream side Fluid flows through the gap between the valve body 4 and the valve body 4, and a part of the fluid that is accelerated and flows downstream flows in the direction of the semicircular portion 2b along the downstream surface of the valve body 2, and flows toward the downstream side of the valve body 2. The groove-shaped gaps 11b formed between the plurality of protrusions 11a of the comb-like protrusions 11 protruding from the surface of the valve body 2 are moved outward from the center of the valve body 2. It circulates to clean the gaps.

Further, a part of the fluid that flows through the gap between the peripheral edge of the semicircular portion 2b of the valve body 2 and the valve body 4, and is accelerated and flows downstream, flows so as to clean the outside of the comb-like protrusions 11. The butterfly valve 1 is automatically cleaned by removing solid objects such as dirt caught in the comb teeth 11, and the groove-shaped gaps in the comb teeth 11 are cleaned by this cleaning. Solid matter such as dirt that has gotten into the pipe 11b can be easily removed and cleaning can be completed without removing the butterfly valve 1 from the piping or cutting off the fluid flow.

After cleaning is completed, rotate the valve stem 3 to remove the valve body 2.
The state is returned to the opening degree before full opening, and the fully open position stopper bolt 16 is set in the stopper device 5 again, thereby returning to the normal operating state.

In this embodiment, the fan-shaped stopper 14 with an arc of 105 degrees is used as the stopper of the stopper device 5, but the length of the fully closed position stopper bolt 15 is made longer than the length of the fully open position stopper bolt 16, and the stopper with an arc of 90 degrees is used as the stopper of the stopper device 5. A fan-shaped stopper may also be used.

In addition, in this embodiment, the seal portion 2a of the valve body 2 was brought into contact with the rubber valve seat 10 in a slightly inclined state to close it, but it was closed by contacting the rubber valve seat 10 at right angles. In this case, the fully open position of the valve body is from the fully closed position to the valve opening direction.
The position is rotated 90 degrees.

Further, on the outwardly extending portions of the fully closed position stopper bolt 15 and the fully open position stopper bolt 16 of the stopper device 5, there are provided both stopper bolts 15 in a state where the rotation of the valve stem 3 is stopped at the fully closed position or the fully open position of the valve body, respectively. If the setting position mark 16 is provided, it will serve as a guide for setting when assembling the butterfly valve 1, adjusting the seal pressure resistance, adjusting the maximum flow rate, etc. Further, a display device may be provided on the upper surface of the reducer 6 provided on the upper part of the valve box 4 of the butterfly valve 1 to indicate the opening degree of the valve body 2 or the fully closed position, fully open position, and cleaning position.

Furthermore, instead of the comb-like protrusions 11 and 12, a valve body is provided which has a large number of pores penetrating through the front and back sides of the valve body to control the flow of fluid, and the pores are clogged with dirt, etc. It can also be applied to butterfly valves that require the removal of solids.

〔Effect of the invention〕

As explained above, the present invention rotates a valve body supported by a valve stem and rotatably arranged in a valve box from a fully closed position in an open direction, and moves the valve body beyond a fully open position. Since the butterfly valve is further rotated in the same rotational direction to clean the debris caught on the comb-shaped protrusions, the butterfly valve can be removed without removing the butterfly valve from the piping and without interrupting fluid flow. Solid objects caught on the comb teeth of the valve can be easily removed.

In addition, it has a reducer that can rotate the valve body from a fully closed state to an opening larger than the fully open state via the valve stem, and a function to stop the rotating valve body in the fully closed and fully open positions. Equipped with a stopper device that allows the function to stop the valve to be released from the outside, it is possible to clean the valve body with a simple structure, and the cleaning work of the valve body becomes easy.
The butterfly valve can be cleaned frequently,
It is possible to prevent damage to the valve seat portion, the seal portion of the valve body, etc., and also to restore the fluid control characteristics of the butterfly valve, which has the effect of easily ensuring normal operation of the butterfly valve. .

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a front view showing the entire butterfly valve, Fig. 2 is a partially sectional side view, and Fig. 3 is a side view of Fig. 2 showing the stopper device. The sectional views and FIGS. 4 to 7 are explanatory diagrams showing the relationship between the state of the valve body and the fluid to be controlled,
Figure 4 is a cross-sectional plan view showing the valve body in its fully closed state;
FIG. 6 is a cross-sectional plan view showing the valve body in a small opening range, FIG. 6 is a cross-sectional plan view showing the valve body in a fully open state, and FIG. 7 is a cross-sectional plan view showing the valve body in a cleaned state. DESCRIPTION OF SYMBOLS 1...Butterfly valve, 2...Valve body, 2a...Seal portion, 3...Valve stem, 4...Valve box, 5...Stopper device, 6...Reducer, 7...Input shaft, 10... …
Rubber valve seat, 11, 12... comb tooth-shaped projection, 11a,
12a...Protrusion, 11b, 12b...Groove gap,
13...Tubular casing, 14...Stopper, 1
5... Fully closed position stopper bolt, 16... Fully open position stopper bolt, 17... Lock nut.

Claims (1)

[Scope of Claims] 1. A method for cleaning a butterfly valve for removing solid matter such as dirt caught in the comb-like protrusions of a butterfly valve having comb-teeth-like protrusions on the front and back peripheral edges of the valve body, comprising: A valve body supported by a rod and rotatably disposed in a valve box is further rotated in the same rotation direction beyond a fully open position where the valve body is rotated from a fully closed position in an open direction. . A method for cleaning a butterfly valve, which comprises cleaning dirt and the like caught on the comb-like protrusions with a fluid flowing through the piping. 2. In a butterfly valve having comb-like protrusions on the front and back peripheral edges of the valve body, the valve body is supported by a valve stem and rotatably arranged in a valve box, and the valve stem is A reducer that can rotate the valve body from a fully closed state to a fully open state or more in the opening direction through the A butterfly valve characterized in that it is equipped with a stopper device that can be released from the outside.