JP2018141481A - Valve element of butterfly valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent attachment of marine organism by preventing lowering of a flow speed on a downstream side of a boss portion by delaying separation of flow near the boss portion.SOLUTION: A valve element 10 of a butterfly valve includes a boss portion 12 extended in a direction of a turning shaft of a disc portion 11, in which the disc portion 11 is gradually thickened from an outer peripheral side toward a central side, and the boss portion 12 is projected to a thickness direction from a surface of the disc portion 11. A fillet portion 13 of which gradient is gradually increased from the disc portion 11 toward the boss portion 12, is disposed on a boundary part between a downstream side of the boss portion 12 and the disc portion 11. A projection dimension from the disc portion 11 and a width dimension of the fillet portion 13 are large on an outer peripheral side of the disc portion 11 and gradually reduced toward a center side. Further, the fillet portion 13 is not disposed on a boundary part between an upstream side of the boss portion 12 and the disc portion 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a valve body of a butterfly valve provided in instrumentation equipment such as petroleum and chemical plants, power generation equipment, and piping for industrial water and hydroelectric power generation equipment.

  In general, as shown in FIG. 6, a valve body 50 of a butterfly valve, which is widely used in various fields, is used for a turning operation in which the center is a turning shaft toward the radial direction of a disk portion 51 that opens and closes a flow path. A cylindrical boss portion 52 for inserting the valve rod 62 is provided, and the boss portion 52 has a shape protruding from the surface of the disk portion 51 in the thickness direction.

  In such a valve body 50 of the butterfly valve, the flow separation occurs near the downstream side of the boss portion 52 in a state where the flow path is opened, and a region where the flow velocity is reduced is generated. In such a case, marine organisms S such as barnacles may adhere to the portion, and damage to the valve seat or the like may occur as the valve body 50 rotates.

  As a countermeasure, Patent Document 1 below discloses that the shape of the cross section in the radial direction of the disk portion is a rhombus shape so that the boss portion does not protrude from the surface of the disk portion, thereby reducing pressure loss and preventing flow separation. However, it describes what is intended to prevent the attachment of marine organisms.

  Further, in Patent Document 2 below, although the strength is improved, the cross-sectional shape of the boss portion in the radial direction of the disk portion is a hexagonal shape, a connecting R portion is provided at the boundary portion between the boss portion and the disk portion, and the connecting R There is a description in which the width dimension of the portion gradually increases from the outer peripheral side to the center side of the disk portion.

  Moreover, in the following Patent Document 3, a nozzle member having a large number of nozzle holes is attached along the side surface of the peripheral portion of the portion that is the downstream side of the disk portion, and each nozzle hole has a large diameter on the upstream side and a downstream side on the downstream side. A taper shape having a small diameter has been proposed to suppress adhesion of marine organisms by a sweeping effect of a jet that is ejected at a higher flow velocity from a nozzle hole.

JP 61-105373 A JP2012-47205A JP 2006-94993 A

  However, even if the valve body is shaped as described in Patent Documents 1 and 2, separation of the flow in the vicinity of the downstream side of the boss part cannot be sufficiently suppressed, and the boundary part between the downstream side of the boss part and the disk part Marine organisms may adhere to the surface.

  In addition, as described in Patent Document 3, when a nozzle member is attached to the disc portion of the valve body, marine organisms can be prevented from adhering to the downstream peripheral portion of the disc portion. Marine organisms cannot be prevented from adhering to the boundary of the disk.

  Accordingly, an object of the present invention is to delay the separation of the flow in the vicinity of the boss portion, prevent a decrease in the flow velocity on the downstream side of the boss portion, and prevent adhesion of marine organisms.

In order to solve the above problems, the present invention includes a boss portion extending in the direction of the pivot axis of the disk portion, the disk portion gradually increases in thickness from the outer peripheral side to the center side, and the boss portion includes the disk portion. In the valve body of the butterfly valve protruding in the thickness direction from the surface of
At the boundary portion between the downstream side of the boss part and the disk part, a fillet part having a gradually increasing gradient from the disk part to the boss part is provided,
The overhang dimension and the width dimension of the fillet part from the disk part are large on the outer peripheral side of the disk part, and gradually decrease toward the center side.
The fillet portion is not provided at the boundary portion between the upstream side of the boss portion and the disk portion.

  In the valve body of the butterfly valve according to the present invention, the step between the downstream side of the boss part and the disk part is smoothly eliminated according to the direction orthogonal to the turning axis of the disk part as the gradient of the fillet part changes. Therefore, the flow of the flow path follows along the fillet portion on the downstream side of the boss portion without peeling off to the surface side of the disk portion, and the flow velocity on the downstream side of the boss portion is prevented.

  For this reason, when it uses for the channel through which seawater flows, adhesion of marine organisms to the boundary portion between the downstream side of the boss part and the disk part is prevented.

  In addition, even when used in a flow path other than seawater, the accumulation of contaminants at the boundary between the downstream side of the boss and the disc portion is prevented, so damage to the valve body and valve seat due to the inclusion of contaminants Is prevented.

The partially cutaway perspective view which shows the butterfly valve provided with the valve body which concerns on embodiment of this invention Longitudinal side view showing a state in which the flow path is opened Cross-sectional plan view Schematic diagram showing the flow near the valve body Schematic diagram showing the flow near the valve when a fillet is provided on the upstream side in addition to the downstream side of the boss Schematic diagram showing the flow near the conventional general valve body

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  The butterfly valve shown in FIGS. 1 to 3 includes a valve body 10 according to the present invention. The valve body 10 is provided with a cylindrical boss portion 12 for inserting the valve rod 2 for turning operation so as to extend in the direction of the turning axis of the disk portion 11 that opens and closes the flow path of the valve box 1. The boss part 12 has a shape protruding from the surface of the disk part 11 in the thickness direction.

  In order to reduce pressure loss, the disk portion 11 is gradually convex from the outer peripheral side to the center side so that the surfaces on both sides form a bulging curved surface, and has a convex lens shape.

  The boss portion 12 has a projecting dimension in the thickness direction from the surface of the disk portion 11 that gradually decreases from the outer peripheral side to the center side of the disk portion 11. In addition, the boss portion 12 does not protrude from the disc portion 11 at the center of the disc portion 11.

  At the boundary between the downstream side of the boss portion 12 and the disk portion 11, a fillet portion 13 is provided that smoothly curves and projects from the disk portion 11 to the boss portion 12 so that the gradient gradually increases. The fillet portion 13 is not provided at the boundary portion between the upstream side of the boss portion 12 and the disk portion 11.

  The width of the fillet portion 13 at each position in the radial direction of the disk portion 11 is large on the outer peripheral side of the disk portion 11 and gradually decreases toward the center side. The width of the fillet portion 13 is eliminated at the center of the disk portion 11.

  In the valve body 10 of the butterfly valve as described above, the step between the downstream outer peripheral surface of the boss portion 12 and the surface of the disk portion 11 is perpendicular to the swivel axis of the disk portion 11 as the fillet portion 13 changes in gradient. Since it is eliminated smoothly according to the direction, the flow of the flow path passes along the downstream side of the boss part 12 without peeling to the surface side of the disk part 11 as schematically shown in FIG. As a result, a decrease in the flow velocity on the downstream side of the boss portion 12 is prevented.

  For this reason, when it uses for the flow path through which seawater flows, attachment of marine organisms to the downstream side of the boss part 12 and the boundary part of the disk part 11 is prevented.

  Further, even when used in a flow path other than seawater, the accumulation of contaminants at the boundary between the downstream side of the boss portion 12 and the disk portion 11 is prevented. Seat damage is prevented.

  By the way, the fillet part 13 as described above is provided not only on the downstream side of the boss part 12 but also on the boundary part between the upstream side of the boss part 12 and the disk part 11 as schematically shown in FIG. The flow is accelerated by the upstream fillet portion 13, and on the other hand, the flow is easily separated from the surface of the disk portion 11 on the downstream side of the boss portion 12, and the marine organism S adheres. The part 13 is provided only on the downstream side of the boss part 12.

  In the above embodiment, the valve body 10 is exemplified by a concentric structure valve in which the central axis of the valve stem 2 passes through the center of the disk portion 11 and is positioned on the central axis of the flow path. The structure of the valve body provided with the fillet portion 13 is also applied to an eccentric structure valve that passes through a position where the central axis of the valve stem 2 is deviated from the center of the disk portion 11 and through a position deviated from the central axis of the flow path. it can.

DESCRIPTION OF SYMBOLS 1 Valve box 2 Valve stem 10 Valve body 11 Disc part 12 Boss part 13 Fillet part S Marine life

Claims (1)

The disc portion (11) includes a boss portion (12) extending in the direction of the turning axis, the disc portion (11) is gradually thickened from the outer peripheral side to the center side, and the boss portion (12) is the disc In the valve body (10) of the butterfly valve protruding in the thickness direction from the surface of the section (11),
A fillet portion (13) having a gradually increasing gradient from the disc portion (11) to the boss portion (12) is provided at the boundary portion between the downstream side of the boss portion (12) and the disc portion (11),
The projecting dimension and width dimension of the fillet part (13) from the disk part (11) are large on the outer peripheral side of the disk part (11), and gradually decrease toward the center side,
The valve body of a butterfly valve, wherein the fillet portion (13) is not provided at a boundary portion between the upstream side of the boss portion (12) and the disc portion (11).

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