A Dynamic Technique for Particulate Removal from Automotive Air Intake Systems

The role of the Heating Ventilation and Air Conditioning (HVAC) system of passenger vehicles is to maintain the ambient environment within the vehicle at a temperature and humidity comfortable for the occupants, regardless of the external weather conditions. A commonly occurring problem in vehicles incorporating an HVAC system is that of unwanted water ingress into the cabin space. This occurs mainly in wet weather conditions, and is caused by the penetration of water through the cowl box and air filter. Large droplets are broken up by the blower motor into a fine mist that can collect in the interior of the car, causing window fogging, damage to carpets and passenger discomfort. Numerous solutions have been implemented by the automotive industry ranging from the placement of baffles within the cowl box of the vehicle to the use of variable area ducts. The aim of these devices is to separate the water phase from the air stream upstream of the blower so that the air carried into the cabin is dry. This paper describes a device that has been designed to dry the air at the blower stage with minimal pressure drop and noise generation but with a high separation efficiency.