JPH0218466B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a cage valve equipped with a cage having windows in its peripheral wall.

[Prior art]

Generally, control valves also start and stop the flow, but
Since the main purpose is to change the flow rate, it is necessary to have a certain relationship between the displacement of the movable part and the flow rate, that is, a flow rate characteristic. For this reason, cage valves are widely used as control valves because they can change the flow rate characteristics to the desired value by changing the shape of the window provided in the cage, are resistant to vibrations, and operate smoothly even at high differential pressures.

As shown in FIGS. 1 and 2, the conventional cage valve has a valve main body 1 having compartments 3 and 4 that are partitioned vertically by a partition wall 2, and an inlet 5a on both sides of each compartment 3 and 4, respectively. and the outlet 5b is opened. On the partition wall 2 of the valve body 1, a cylindrical cage 7 having a plurality of windows 6a to 6d on the peripheral wall is provided with a lid body 8.
Fixed by A plug 10 supported by a valve shaft 9 is inserted into the cage 7 so as to be movable up and down, and the plug 10 is raised and lowered by the valve shaft 9 to increase and decrease the opening area of the windows 6a to 6d to adjust the flow rate. It is composed of

However, in conventional cage valves of this type, the flow rate per unit time, that is, the capacity of the valve, is
There was a problem that the _CV value was limited. This is because the windows 6a to 6d of the cage 7 are provided radially from the axis of the cage 7, and as a result, fluid flows centripetally into the cage 7 as shown by the arrows. As a result, they violently collide with each other near the center of the cage 7, and the fluid flow is greatly disturbed, which affects the flow velocity of the fluid passing through the cage valve.

[Summary of the invention]

The present invention has been developed in view of the above circumstances, and is extremely unique in that the opening side edge of the window of the cage is inclined in a certain direction, and the flow path from the inlet to the cage is formed with its center offset from the axis of the cage. To provide a cage valve that can increase the capacity of the valve with a simple configuration. Furthermore, the present invention provides a cage valve in which the capacity of the valve can be further increased by forming the flow path formed by the valve body and the cage into a spiral shape that gradually becomes narrower. Hereinafter, its configuration and the like will be explained in detail with reference to embodiments shown in the drawings.

〔Example〕

FIG. 3 is a cross-sectional view showing a cage valve according to the present invention, and FIG. 4 is a longitudinal cross-sectional view. In these figures, the same or equivalent members as shown in FIGS. 1 and 2 are designated by the same reference numerals. , and its explanation will be omitted. 11 are four windows 6a~ opened at equal intervals.
Among the opening edges forming 6d, these opening side edges 11, 11...
is set to be inclined in a constant direction with respect to a plane that includes the axis of the cylindrical cage 7 and extends in the radial direction, and in this embodiment, is inclined counterclockwise when viewed from above. In other words, the windows 6a to 6d of the cage 7
is opened so as to face a surface in contact with the outer peripheral surface of the cage 7 in a direction inclined clockwise when viewed from above. These opening side edges 11, 11 are provided in the thick cage 7, so they have a width in the direction of fluid flow, and can guide the fluid flowing into the valve body 1 along its surface. can. That is, the opening side edges 11, 11... are the window 6.
They are averagely inclined at an angle that changes the flow of the fluid flowing into the cage 7 through points a to 6d, causing it to swirl clockwise. The shape is preferably a curved surface along which a spiral curve follows, or a plane close to it, and may be either a plane or a curved surface as long as it has an average inclination.

Reference numeral 12 denotes a flow path from the inlet 5a to the cage 7, and the flow path 12 is formed in the compartment 3 of the valve body 1 with its center shifted laterally by a predetermined distance D from the axis of the cage 7. This predetermined distance D is such that the flow path 12 faces substantially one side of the cage 7, in other words, the fluid is allowed to flow into the flow path 13 formed by the inner circumferential wall of the valve body 1 and the outer circumferential wall of the cage 7. In the constant circumferential direction embodiment, it is set to flow clockwise.

In the cage valve configured in this way, the fluid that flows into the compartment 3 of the valve body 1 from the inlet 5a is
After passing through the flow path 12, a part of the fluid flows into the cage 7 through the window 6a, and the other fluid flows into the flow path 13 in a constant circumferential direction. The fluid flowing into the cage 7 is guided in a constant clockwise direction when viewed from above by the opening side edges 11, 11 of the window 6a. Also, flow path 1
The fluid flowing into the cage 3 sequentially flows into the cage 7 through the windows 6b to 6d while rotating clockwise, and is guided clockwise by the opening side edges 11, 11, . . . . At this time, since the flow direction in the flow path 13 and the direction in which the fluid is guided are the same clockwise direction, the fluid can smoothly flow into the cage 7. Inside the cage 7, the fluid flows in a spiral manner along the inner peripheral wall surface of the cage 7, and the circumferential velocity of this flow increases as it approaches the center, so the pressure naturally decreases near the center, and the fluid flows around the cage 7. It is pushed downstream due to the pressure difference with the external pressure. That is, the center is attracted toward the lower circular opening of the cage 7.

Therefore, the fluid passing through this cage valve is prevented from violently colliding with each other in the cage 7 as in the conventional case, and there is no flow disturbance due to this collision, and moreover, the fluid flows smoothly into the cage 7. , it draws smoother streamlines than before. As a result, energy loss can be reduced and the speed of fluid passing through the cage valve can be made faster than in the past.

FIG. 5 is a cross-sectional view showing another embodiment of the cage valve according to the present invention.
Components that are the same or equivalent to those shown in the figures are given the same reference numerals, and their explanations will be omitted. In this embodiment, the flow path 13 formed by the inner circumferential wall of the valve body 1 and the outer circumferential wall of the cage 7 is formed in a spiral shape whose cross section gradually narrows in the circumferential direction, that is, clockwise. The configuration is similar to that shown in FIG. 4 and FIG.

Also in the cage valve configured in this manner, fluid can flow smoothly into the cage 7 and can be rotated clockwise within the cage 7 to prevent fluid collision. Furthermore, since the flow path 13 is formed to become gradually narrower, the fluid is guided toward the cage 7 by the inner circumferential wall of the valve body 1.
As a result, the fluid can flow smoothly and efficiently into the cage 7, so that the speed at which the fluid passes through the cage valve can be further increased.

It goes without saying that the openings of the windows 6a to 6d may have any shape, such as a rectangular shape, that can provide the desired flow characteristics.

〔Effect of the invention〕

As explained above, according to the present invention, the opening side edge of the window of the cage is inclined in a certain direction, and the flow path from the inlet to the cage is formed offset from the cage.
Fluid can flow into the cage and be guided in a swirling manner.

Therefore, since it is possible to prevent the fluids from colliding with each other and to increase the speed of passage through the cage valve, there is an effect that the capacity of the valve can be increased.
Further, since the flow path formed by the valve body and the cage is formed to gradually become narrower, it is possible to efficiently and smoothly flow the fluid into the cage. Therefore, the speed of fluid passing through the cage valve can be further increased, and the capacity of the valve can be further increased.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view showing a conventional cage valve;
FIG. 3 is a cross-sectional view showing the cage valve according to the present invention, FIG. 4 is a vertical cross-sectional view,
FIG. 5 is a cross-sectional view showing another embodiment. 1...Valve body, 5a...Inlet, 6a-6d...Window, 7
... Cage, 11... Opening side edge, 12, 13... Channel.

Claims (1)

[Scope of Claims] 1. In a cage valve equipped with a cylindrical cage having a plurality of windows on a peripheral wall and fixed to a valve body, the opening side edge of the window is inclined in a certain direction, and the opening side edge of the window is inclined in a certain direction, and A cage valve characterized in that a flow path leading to the cage is formed so that its center is offset laterally from the axis of the cage. 2. In a cage valve equipped with a cylindrical cage having a plurality of windows on the peripheral wall and fixed to the valve body, the opening side edge of the window is inclined in a certain direction, and the flow path from the inlet to the cage is formed. The center is formed so as to be shifted laterally from the axis of the cage, and the flow path formed by the inner circumferential wall of the valve body and the outer circumferential wall of the cage is formed in a spiral shape that gradually narrows in the circumferential direction. cage valve.