초록 ▼

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 t

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.

대표청구항 ▼

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 sa

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.