The solution of noise problem in the selection of regulating valve

The noise on regulating valve is the main pollution source in petrochemical production. Control valve noise should be prevented from three aspects.

01. Noise caused by vibration

Vibration noise generally comes from the vibration of the spool. For example, when the spool moves horizontally in the sleeve, the gap between the spool and the sleeve can be small or the sleeve with hard surface can be used. Such as spool or other components, they have a natural vibration frequency, which can be changed by special casting or forging treatment of the characteristics of the spool, if necessary can also be replaced with other types of spool. Such as the noise generated by the fluid pressure fluctuation caused by the oscillating displacement of the spool, this situation is generally caused by the damping factors such as the actuator of the adjustment loop, which can be adjusted to adjust the damping coefficient or add damping facilities in the direction of the spool displacement.

02. Aerodynamic noise due to high velocity airflow

There are currently three ways to avoid aerodynamic noise. First, eliminate noise sources and limit fluid velocity through the regulator; Secondly, the use of special structure of the valve body, so that the fluid through the valve core seat of the tortuous flow path gradually decelerate; Third, the porous flow limiting plate should be used, which absorbs part of the pressure drop after the regulator, so as to reduce the flow rate through the regulator, so as to achieve the purpose of noise reduction.

03. Prevent fluid dynamics noise

Cavitation is accompanied by noise and vibration. This noise, also known as hydrodynamic noise, has been described before how to avoid cavitation.