JP2000257731A - Flow passage selecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To switch the fluid flow passage with a high speed without generating a water hammer and a rapid pressure change. SOLUTION: This device is provided with a sealed up casing 12 installed on the branch point of a single upstream flow passage 1 and two lower stream side flow routes 2, 3 and a movable valve element 14 for gradually increasing its one side and gradually decreasing the other side, while keeping the opening area sum of two lower stream side flow routes provided in the casing to a constant. The casing 12 has a three-forked road 12a for connecting the upper stream side flow route with two lower stream side flow routes and the movable valve element 14 has an arc surface 15 for sliding while sticking to the casing 12. By swinging the movable valve element around the center axis 14a of the arc surface 15, both ends 15a, 15b of the arc surface open/close the opening of the lower stream side flow route respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow path switching device for switching a flow path while suppressing pressure fluctuation.

[0002]

2. Description of the Related Art In a liquid flow path as exemplified in FIG. 3A, for example, when a valve 4 (for example, a gate valve or a butterfly valve) is rapidly closed in order to stop the flow between the main flow lines 1 and 2. A so-called water hammer phenomenon may occur, causing excessive pressure fluctuation and damaging valves and other equipment. Therefore, close the valve slowly, check valve in the middle of the line (check valve)
In some cases, a countermeasure such as installing a liquid reservoir or providing a liquid reservoir in a line may be taken. However, there are problems such as the inability to quickly close, an excessive pressure loss, and the incorporation of gas into the liquid.

In the case of a gas flow path, particularly when a valve in a high-speed airflow line is suddenly changed or closed, a pressure wave or an expansion wave propagates before and after the valve, resulting in an excessive pressure fluctuation.
There are problems such as damage to equipment and difficulty in precise measurement with test equipment.

[0004]

In order to solve the above-mentioned problems, in order to switch the flow path of the fluid (liquid and gas), as shown in FIG. Valves 4 and 5 (for example,
In some cases, a gate valve or a butterfly valve) is provided, and the opening and closing of the two valves are synchronized by a mechanical or electrical synchronization mechanism 6. However, this means has a problem that the synchronization mechanism 6 is complicated and expensive.

The present invention has been made to solve such a problem. That is, an object of the present invention is to provide a flow path switching device capable of switching a fluid flow path at a high speed without generating a water hammer or a rapid pressure fluctuation.

[0006]

According to the present invention, a sealed casing (12) installed at a junction of a single upstream flow path (1) and two downstream flow paths (2, 3). And a movable valve body (14) provided in the casing and gradually increasing one of the two downstream flow paths (2, 3) and gradually decreasing the other while keeping the sum of the opening areas constant. A flow switching device is provided.

According to the configuration of the present invention, the movable valve element (1)
According to 4), while the sum of the opening areas of the two downstream flow paths (2, 3) is kept constant, one of the flow paths is gradually increased and the other is gradually reduced. Since there is almost no change, no water hammer or sudden pressure fluctuation occurs, and the pressure fluctuation can be suppressed.

According to a preferred embodiment of the present invention, the casing (12) has a three-way channel (12a) connecting the upstream channel (1) and the two downstream channels (2, 3). The movable valve element (14) has an arc surface (15) that slides in close contact with the casing, and has a central axis (14) of the arc surface.
a) is a fan-shaped member that can swing around the center of the arc-shaped surface.
One of the openings in 3) is opened and closed.

With this configuration, the movable valve element (14) is swung about the central axis (14a) of the arcuate surface (15) so that one of the two end portions (15a, 15b) has a downstream flow path. Can be gradually increased while it is gradually decreased. Therefore, the two downstream channels (2, 2) have a relatively simple structure.
While keeping the sum of the opening areas of 3) constant, one of them can be gradually increased and the other can be gradually decreased.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall perspective view of a flow path switching device of the present invention, and FIG. 2 is a schematic configuration diagram of FIG. As shown in FIGS. 1 and 2, the flow path switching device 10 of the present invention includes a sealed casing 12 and a movable valve element 14.

The casing 12 is a hermetically sealed (water-tight or air-tight) vessel installed at a branch point between the single upstream flow path 1 and the two downstream flow paths 2 and 3, and has an upstream flow path inside. Trifurcated channel 12a connecting channel 1 with two downstream channels 2, 3
Having. In addition, a valve seat 12b is provided on the inner surface of the three-way channel 12a so as to come into contact with an end (described later) of the movable valve element 14.

As shown in FIG. 2, in this embodiment, the movable valve element 14 has an arcuate surface 15 that slides in close contact with the casing 12. The movable valve element 14 is a fan-shaped member that can swing about a central axis 14 a of the arc surface 15. Also,
Both ends 15a and 15b of the circular arc surface 15 open and close one of the openings of the downstream flow paths 2 and 3, respectively. The movable valve element 14 can swing about its central axis 14a by a driving mechanism (not shown). This drive mechanism may be operated manually or automatically.
With this configuration, by merely swinging the movable valve body 14 about the central axis 14a, one of the two downstream passages 2 and 3 is gradually increased while the sum of the opening areas thereof is kept constant, and the other is gradually decreased. be able to.

According to the construction of the present invention described above, the movable valve element 14 gradually increases one of the two downstream flow paths 2 and 3 while maintaining the sum of the opening areas of the two downstream flow paths 2 and 3 and gradually decreases the other. Even when the flow path is switched at a high speed, there is almost no change in the flow velocity of the fluid, so that water hammer or abrupt pressure fluctuation does not occur, and the pressure fluctuation can be suppressed.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified without departing from the gist of the present invention.

[0015]

As described above, according to the flow path switching device of the present invention, one end (for example, 15a) of the valve element 14 is
When one of the flow paths (for example, the downstream flow path 2) is closed by contacting the valve seat 12b provided in the inside 2a, the other flow path is opened. Further, at the time of this switching, the passage cross-sectional areas of the two flow paths are always constant, even during the switching.

Therefore, even when switching at high speed, the switching can be performed without delay and the total cross-sectional area of the flow path can be maintained under a constant condition, so that water hammer and sudden pressure fluctuation occur. The influence on the upstream side and the downstream side can be greatly reduced without performing.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of a flow path switching device of the present invention.

FIG. 2 is a schematic configuration diagram of FIG.

FIG. 3 is a diagram showing an example of conventional flow path switching.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upstream flow path 2, 3 Downstream flow path 4, 5 Valve 6 Synchronization mechanism 10 Flow path switching device 12 Casing 12a Trifurcated flow path 12b Valve seat 14 Movable valve element 14a Central axis 15 Arc surface 15a, 15b Both ends

Claims (2)

[Claims] 1. A sealed casing (12) provided at a branch point between a single upstream flow path (1) and two downstream flow paths (2, 3); A movable valve element (14) for gradually increasing one of the two downstream flow paths (2, 3) while maintaining the sum of the opening areas thereof, and gradually decreasing the other;
A flow path switching device comprising: 2. The casing (12) has a three-way flow path (12a) connecting an upstream flow path (1) and two downstream flow paths (2, 3). ) Is a fan-shaped member having an arc surface (15) that slides in close contact with the casing and that can swing about a central axis (14a) of the arc surface, and both end portions (15a, 15b) of the arc surface. 2. The flow path switching device according to claim 1, wherein each of the openings opens and closes any one of the downstream flow paths.