Fan Silencer for Car Parks and Tunnels

The process

Basement car parks and tunnels use jet fans and extract fans rated for smoke extract, with silencers at the discharge. The fans run on carbon monoxide sensors in normal operation and at full speed in a fire.

The gas at the fan

Ambient air with vehicle exhaust, moved by jet fans and extract fans, with the smoke extract case setting the high temperature rating of the motor.

Selection for this duty

Construction	Absorptive annular design in mild steel; stainless steel where the gas is wet or corrosive
Density at the fan	At about 35°C the gas density is close to 1.15 kg/m³, 95% of standard air. Pressure developed and power drawn fall in the same ratio, so the selection is made at this density and the motor is checked at cold start.

An absorptive silencer at the fan inlet, outlet or in the duct, cutting fan noise with minimum pressure loss. Client-stated blade types for the Fan Silencer in general: Silencer.

Industries

Other fans in car parks and tunnels

Fan Silencer in other processes

Information needed to select or quote

1. Gas volume and temperature. Actual flow at the inlet, normal and upset temperature, moisture.
2. Dust or pollutant. Inlet loading, particle size distribution, whether it is abrasive, sticky, hygroscopic or combustible; for gases, the species and concentration.
3. Required outlet. The emission limit or clean gas concentration the unit must meet.
4. Site. Available space and height, material of construction preferences, and how the collected material is to be discharged.