Fluid flow control valve with maximized noise reduction

• US 4,397,331 A
• Filed: 09/29/1978
• Issued: 08/09/1983
• Est. Priority Date: 09/29/1978
• Status: Expired due to Term

• Current Assignee: GS Development Corporation
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: Medlar, Lewis A.
• Primary Examiner(s): Rosenthal, Arnold
• Application Number:
  US05/947,265
• Time in Patent Office: 1,775 Days
• Field of Search: 137/625.37, 137/625.38, 137/625.3, 137/375, 251/127
• US Class Current: 137/375
• CPC Class Codes: F16K 47/02 for preventing water-hammer or noise
• CPC Class Codes: F16K 47/08 for decreasing pressure or noise level and having a throttling member separate from the closure member , e.g. screens, slots, labyrinths
• CPC Class Codes: Y10T 137/7036 Jacketed
• CPC Class Codes: Y10T 137/86734 With metering feature
• CPC Class Codes: Y10T 137/86799 With internal flow passage

Abstract

The valve includes a perforated cage and a perforated closed end tube operating as two sequential stages of restriction and pressure drop for the fluid flowing through the valve. A movable plug cooperates with the cage to control the net amount of flow restriction presented to the fluid, and hence to control the pressure drop across the valve and the rate of fluid flow through the valve. The tube perforations are sized to turn back the practical maximum of the first stage noise into the tube, and the latter is lined with material which absorbs a maximum of the turned-back noise. As a result, the level of the noise passing downstream of the valve is minimized.

Claims

1. In a fluid flow control valve having a fluid path, means for controlling the effective area of said path, and a perforated member having its perforations located in fluid pressure dropping relationship in said path, the improvement for minimizing the noise produced by the passage of fluid through said perforations, comprising

a perforated wall located in cooperative relation to said perforated member to form a chamber on the downstream side of said member perforations, the wall perforations in said wall being of a size to establish a maximized noise cutoff frequency to cause that portion of said noise having frequencies below said cutoff frequency to be reflected back into said chamber and to follow a noise path through the solid parts of said wall, thereby to maximize the separation of the path of said noise from the path of the fluid through said wall perforations, and

a noise absorbing lining located on the interior surface of said wall within said chamber to absorb said reflected noise along said noise path and thus minimize the transmission of said noise downstream of said chamber.

2. In a fluid flow control valve having a fluid path, means for controlling the effective area of said path, and a perforated member having its member perforations located in fluid pressure dropping relationship in said path to provide a first pressure dropping stage, the improvement for minimizing the noise produced by the passage of fluid through said perforations, comprising

a second pressure dropping stage located along said fluid path downstream of said first stage, said second stage including a perforated wall having wall perforations and forming with said perforated member a chamber between said member perforations and said wall perforations, the latter being of a size to minimize the passage of said noise through said wall perforations, whereby a maximum of said noise is reflected back into said chamber by said wall perforations and is forced to follow a noise path through the solid parts of said wall, and a maximum separation between the path of said noise and the fluid path through said wall perforations is thus produced, and

a noise absorbing lining located on the interior surface of said wall within said chamber to absorb said reflected noise along said noise path and thus minimize the transmission of said noise downstream of said second stage.

3. In a fluid flow control valve including a body having a fluid inlet passageway and a fluid outlet passageway, including a cage having a cage wall and seat and a set of perforations passing through said cage wall, said cage being secured with said body to place said seat and said perforations in series in a fluid path between said passageways, and including a plug slidably fitted within said cage and having a plug seat, said plug being axially movable in said cage between a first position wherein said plug seat engages said cage seat and interrupts said path, and a second position wherein said plug seat is separated from said cage seat to open said path, the improvement for minimizing the noise produced by the passage of fluid through said perforations, comprising

a closed end tube secured to said cage and having a wall which cooperates with said cage wall to form a chamber on the downstream side of said cage perforations, said tube wall containing wall perforations which are sized to minimize the passage of said noise therethrough and to reflect a maximum of said noise back into said chamber to cause said reflected noise to follow a noise path through the solid parts of said tube wall, whereby a maximum separation is produced between the path of said noise and the path of the fluid through said wall perforations, and

noise absorbing means associated with said tube to absorb said reflected noise along said noise path and thus minimize the transmission of said noise downstream of said chamber, wherein said noise absorbing means consists of a noise absorbing lining located on the interior surface of said wall within said chamber to absorb said reflected noise along said noise path.