The P-SLF sterile air unit is a multi-stage filtration system that offers a solution for low pressure, high volume, sterile air in critical processed food and beverage applications.
The compact mobile unit consists of a pre-filter and a sterile filter with a low pressure blower. Various sizes with flow rates of 30 to 910 m3/h / 17 to 536 scfm are available.
The blower draws ambient air (1) into the filtration chamber (2). The air is cleaned with a prefilter on the upstream side of the blower. The retained particles will cause an increase in differential pressure over time. To protect the blower (4), a vacuum relief valve (3) is installed. The blower compresses (4) the air to about 1.5 psi. The compressed air is fed into the sterile chamber (5) where a sterile filter retains bacteria and other contaminants. To protect the blower, a pressure relief valve will open if the sterile filter is blocked. At the outlet (11) the sterile air is fed to the tank or other point of use.
During sterilization of the upper chamber and filter elements, the disc valve (7) needs to be closed to prevent steam from entering the blower. To maintain good steam quality, a steam filter (8) is standard on the P-SLF box. After sterilization the condensate can be drained out the discharge valve (9) (10).