JPS6360274B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Industrial Application Field This invention applies to a swing type non-water hammer check valve device installed in a water pipeline, and when the pump energy for water supply is suddenly cut off, the water column in the pipeline is The present invention relates to a swing type non-water hammer check valve device that safely and accurately prevents water hammer action caused by backflow of water.

(b) Conventional technology If a check valve installed in a water supply pipeline fails to respond appropriately to changes in the flow in the pipe after the pump is stopped, and the check valve is seated during the backflow process, a water hammer phenomenon occurs on the downstream side of the valve at the moment the valve closes. Depending on the pipeline conditions, water column separation may also induce water hammer, leading to serious accidents.

Conventionally, check valve devices to deal with this problem,
For example, Special Publication No. 40-3654 "Non-water hammer pumping device",
It is well known that there have been a series of inventions such as Japanese Patent Publication No. 51-25930 ``Improvement of non-water hammer pumping device'' and that these inventions have been widely utilized.The present invention is based on the technical idea of this non-water hammer pumping device. It is based on

(c) Problems to be solved by the invention The above-mentioned non-water hammer pumping device, which is a prior art technology, is based on a technical idea that escapes the ambiguous concept regarding the occurrence of water hammer effect, which had been common since then. ,
The check valve has undergone fundamental improvements, such as making the flow path in the valve box wider and smoother, making the valve lift more appropriate, and making the structure of the valve body more movable. However, the invention (Japanese Patent Publication No. 51-25930)
This can be easily seen from the description in the specification of ``Improvement of non-water hammer pumping device'' published in the official gazette.

However, even in such a swing type non-water hammer check valve device, for example, when one of the adjacent pumps suddenly stops during parallel operation, the severe backflow acceleration seen at the pump outlet side can occur. If this happens, the valve seating delay will be severe,
However, it had the disadvantage of inducing water hammer effect.

In order to eliminate these shortcomings, it was found that the following problems needed to be solved.

A: As can be seen in Figure 3, swing-type check valve devices originally have a tendency for the flow to flow toward the front of the valve body, forming a dead zone in the flow path on the back side of the valve body. This dead area may cause a delay in the valve seating movement and induce water hammer.

B In addition, in a swing type check valve device, the valve body tends to be opened wide, as if it were a door opened toward a passage, and the opening angle of the valve becomes too large, causing the valve body to open wide. The displacement distance from the fully open position to the valve seating became longer, and there was a growing resentment that it took too long for the valve to seat.

The problems mentioned above in A and B are instantaneous events that are intertwined with complex conditions, and until now, in fact, it has been considered difficult to appropriately resolve them. And it is based on the Tokko Showa, which has been widely used as a check valve device to prevent water hammer.
The swing type non-water hammer check valve device according to "Improvement of non-water hammer pumping device" described in Publication No. 51-25930 was still an undeveloped technology.

C. Conventionally, in an attempt to shorten the valve closing time of a swing type check valve device, a palliative measure has been easily used in which a stopper is provided on the valve box side to keep the opening of the valve small.

However, in such a swing type check valve device, during steady operation, that is, at a predetermined maximum flow rate, the valve opening force received from the flow increases significantly compared to when the valve begins to open, and the valve body strongly pushes against the stopper. The half-open state is stabilized by the balance of the three acting forces: the drag force (which does not contribute to the valve closing movement), the valve opening force, and the valve closing force that is pressed against the stopper and generated on the stopper contact surface (which does not contribute to the valve closing movement).

Therefore, even if the forward flow begins to decrease and the valve opening force begins to decline, it will continue for a while, that is, until the valve opening force becomes competitive with the valve closing force (until the resistance at the stopper becomes zero). The valve body cannot initiate a closing movement.

Therefore, from this news, it is natural that the valve closes late, but no matter how high the stopper is and the valve opening is kept small, it will not improve the valve closing delay in any way. It also turns out that it is of no use in preventing water hammer, and merely increases valve loss pointlessly.

Moreover, a check valve that suppresses the valve with a stopper and increases valve resistance actually causes negative pressure to grow downstream of the valve in the event of a sudden pump stop, resulting in a water hammer effect due to water column separation. There is even a potential risk of causing an unexpected accident.

This invention fundamentally solves the cause of the delay in valve seating, which was a major problem in preventing the water hammer effect of swing-type check valve devices installed in non-water hammer pumping devices, by universal and principled means. The purpose of this invention is to improve the non-water hammer pumping device by solving the problem and making the valve device a check valve device that has less valve loss and responds accurately to changes in flow.

(d) Means for solving the problem In order to achieve the above object, the swing type non-water hammer check valve device of the present invention has a valve body whose opening position is
When the valve body is in the middle of the flow path in the valve box, that is, the downstream end of the valve body is in the valve fully open position reaching near the pipe axis, which is the flow path in the valve chamber, and the valve receives a predetermined maximum flow of pumped water. It is equipped with a valve closing force member configured to apply a valve closing force that is counterbalanced to the opening force.

In the above case, the valve body part is stably maintained in a floating state in the flow of the structure that hugs its outer peripheral surface, and even when there is a sudden change in the flow,
There is no obstruction to valve seating movement.

Next, the present invention will be described in more detail based on examples and with reference to the drawings.

The drawing shows a sectional view of the swing type non-water hammer check valve device of the present invention in a state where the valve body is opened to a fully open position at a predetermined maximum flow rate.

In the first embodiment shown in FIGS. 1 and 2, 1
3 is the inlet flow path portion of the valve box 2, and 3 is the outlet flow path portion thereof, where the inlet flow path portion 1 has an inlet flow path a, the outlet flow path portion 3 has an outlet flow path b, and the pipe portions are respectively It is constructed almost concentrically with the center of numbers 8 and 9. Reference numeral 4 denotes a valve seat provided at an end of the inlet flow path a, inclined with respect to the horizontal plane, and includes a valve seat opening 11 which is the entrance to the valve chamber.
is provided. Reference numeral 17 denotes a valve chamber outlet located near the downstream end 7 of the valve body portion and formed to face this, and serves as an entrance to a converging flow path of the branch flow paths 14 and 15. The downstream end portion 7 of the valve body portion is located near the pipe axis of the valve chamber outlet 17 when the valve is fully opened.

The shape of the entrance of the collective flow path 17 is set based on the width of the valve seat opening 11, which is the entrance of the valve chamber, but in this embodiment, for simplicity, its diameter is approximately the same as that of the valve seat opening 11. formed equally.

Reference numeral 5 denotes a valve body portion, which is a general term for a valve member comprising a valve closing member 5a, a valve closing force member 5b integrally formed therewith, and a connecting portion 5c.

The valve body portion 5 is rotatably supported by a pivot shaft 6 at its upstream end via a coupling portion 5c.

The valve closing force member 5b always acts with respect to the valve body portion 5.
It is made of a member that applies a predetermined external force (referred to as valve closing force, consisting of gravity, spring force, etc.) in the closing direction, and is formed in a structure that does not disturb the flow as much as possible.

The magnitude of this valve closing force is set to be equal to the acting force in the opening direction received from the flow of the predetermined maximum flow rate when the valve body portion 5 is in the fully open position, that is, the force balanced with the magnitude of the valve opening force. shall be set.

The specific procedure includes, in a pumping state with a predetermined maximum flow rate, adjusting the acting force (weight in the illustrated example) of the valve closing force member 5b as appropriate to balance the valve body 5 to a floating state at the fully open position. etc.

The valve opening force at the above-mentioned predetermined maximum flow rate is called the predetermined maximum valve opening force, and the valve closing force set to counteract this is called the predetermined valve closing force, but both of these are fundamental components of the present invention. This is an important element.

Reference numeral 16 denotes a buffer device that appropriately suppresses rocking due to irregular flow rate fluctuations when the valve body 5 is held in opposition at a predetermined maximum flow rate, and is interposed between the valve box and the valve body. It is an elastic body with a suitable shape.

In the above configuration, the flow that flows into the flow path 12 in the valve chamber from the valve seat opening 11 flows out into the flow path 14 in the valve chamber from the valve opening 13 in the fully open state. At this time, the valve body portion 5 is stabilized in a floating manner with its downstream end 7 facing approximately the center of the collective flow path 17, which is the valve chamber outlet, and dividing the valve chamber diagonally. , a branch channel 15 is formed on the back side of the valve body, and a branch channel 14 is formed around the side surface of the valve body part to the lower valve opening 13, and the flow has a flow structure that hugs the valve body part from the side face to the back face. Form.

(E) Effect In the swing type non-water hammer check valve device configured as described above, at a predetermined maximum flow rate, the valve body portion 5 adjusts the balance between the valve opening force and the valve closing force in the middle of the flow in the valve chamber. Because the valve is originally held in a floating state, even if severe backflow acceleration is suddenly applied to the flow near the valve and the flow velocity begins to decrease, the valve can be caused to begin its seating motion almost at the same time. .

Thus, the present invention has solved the problem of the valve seating delay, which has conventionally been considered extremely difficult to eliminate, as a problem at the moment of the start of movement, and has achieved the problem of eliminating the start delay. This method is a fundamental and fundamental method that can be universally applied to all types of water pumping equipment, and its significance is enormous.

In the present invention, the flow in the valve chamber embraces the valve body portion 5 and is forced toward the collecting flow path 17, so there is no problem of obstruction of valve movement due to stagnation or stagnation. It has been resolved.

(F) Examples As explained above, the swing type non-water hammer check valve device of the present invention has a remarkable effect on preventing water hammer in a pumping device, and in accordance with the gist of the present invention, various structural changes have been made. In addition, it is possible to meet universal implementation requirements. That is, depending on the circumstances of manufacture and use, for example, in the embodiment shown in FIG. 1, a part of the acting force of the valve closing force member 5b may be borne by the buffer member 16.

For example, even if the angle of inclination of the valve seat is approximately 90 degrees, that is, approximately perpendicular to the inlet flow line, a certain effect can be obtained. The valve seat with an inclination angle of 60 degrees, as shown in Figure 1, has a general-purpose structure and is superior in terms of performance and manufacturing, and has enormous industrial effects.

In addition, as this angle of inclination is further reduced and the opening of the valve seat is made into an elliptical, rectangular, or trapezoidal shape, etc. (of course, the valve body shape and flow path shape will become suitable structures). , it is possible to make the valve lift small for a predetermined valve opening area.
In this case, the ratio of the width and length of the valve body and the valve body can be reduced, which is convenient for strong structural design and manufacturing. It has characteristics that make it extremely suitable for water pumping equipment.

FIG. 4 shows an embodiment of the present invention in which the valve seat inclination is reduced to near zero as described above. Similarly, add 30 to the numbers shown in FIG.
It was displayed as 4.45. Note that 46 is a shock absorber made of an elastic member.

(G) Effects of the Invention As explained above, this invention has a simple structure, and is particularly suitable for large-diameter check valve devices installed at various locations in large-scale water supply facilities, etc. It can produce excellent effects in all aspects of performance, maintenance, and management, and its implementation effects are extremely large compared to conventional techniques.

[Brief explanation of drawings]

Fig. 1... A vertical sectional view showing the first embodiment of the present invention, Fig. 2... A plan view showing the first embodiment of the invention, Fig. 3... A longitudinal sectional view showing the conventional example, Fig. 4... This FIG. 7 is a vertical cross-sectional view showing a second embodiment of the invention. 1, 31... Inlet channel section, 2... Valve box, 3, 3
3... Outlet flow path section, 4, 34... Valve seat, 5, 35
...Valve body part, 5a...Valve closing part, 5b...Valve closing force member, 5c,...Choice coupling part, 6, 36...
Rotation shaft, 7, 37... Downstream end, 8, 9,...
... Pipe section, 10, 40... Valve box lid, 11, 41...
... Valve seat opening, 12 ... Channel, 13 ... Valve opening, 1
4, 15, ... branch flow path, 16, 46 ... buffer device, 17, 47 ... collective flow path, a ... inlet flow path,
b...Exit flow path.

Claims (1)

[Claims] 1. When a swing type check valve device is provided in a water pumping device, the valve body portions 5, 35 of the check valve device are
At the time of the predetermined maximum flow rate of pumped water, the valve closing force member exerts an external force in the closing direction that is almost equal to the force in the opening direction received from the flow, that is, the predetermined maximum valve opening force, i.e., the predetermined valve closing force. The valve is held in a fully open position where the side ends 7 and 37 are near the pipe axis, which is the flow path in the valve chamber, and a valve body is disposed between the outer peripheral surface of the valve body and the corresponding inner wall of the valve body. A branch channel 1 having a shape that extends from the side to the back and embraces the part.
4, 15, 44, 45 to form the valve body portion 5,
The collecting flow paths 17, 47 of the outflow flows from the front side, side side, and back side flow paths of the valve body portions 5, 3
5. A swing type non-water hammer check valve device configured to face downstream ends 7, 37 of 5. 2. The shock absorbers 16, 46 are operated when the valve bodies 5, 35 are held in the open position by a valve closing force member that has a force that counteracts the valve opening force received from the flow at a predetermined maximum flow rate. The swing type non-water hammer check valve device according to claim 1, which is provided between the valve box and the back surface of the valve body part. 3. The swing type non-water hammer check valve device according to claim 1, wherein the angle between the closing surface of the valve seat 4 and the streamline in the inlet flow path a is approximately 60 degrees. 4. The swing type non-water hammer check valve device according to claim 1, wherein the shape of the valve body portion 35 is longer in the flow direction than the width thereof.