MANN+HUMMEL Air filters

The term “complete air filter” refers to the air filter element including the housing. Additional components, such as brackets, secondary elements, maintenance switches or indicators, intake and clean-air lines, discharge valves and pre-separators are often either integrated or available separately. 

The housings are typically made of plastic, usually talc or glass fiber-reinforced polypropylene or polyamide. For applications subject to fire protection regulations, such as ships or locomotives, a metal housing is used. Depending on the requirements, the main filter elements may consist of a cellulose medium or – if maximum separation efficiency is required – a glass fiber medium. In terms of elastomers, EPDM / foam rubber are commonly used. 

Pre-separation either takes place via a separate cyclone connected on the air-intake side or via one that is integrated into the housing. High efficiency separators include several small cyclones in front of the filter element; the dust is removed via a discharge valve. Depending on the number of cylinders and degree of turbocharging, the engine either pulsates strongly or weakly. Different discharge valves are available depending on this pulsation intensity. If the machine is serviced in a dusty environment, e.g., agricultural machinery in a field, an additional, secondary element is provided to protect the clean side during servicing, which remains inside the complete filter while the main filter is being changed. The air-intake side of the air filter must be protected to keep the inside of the filter free from water, foreign bodies, and insects. If the air filter is not installed inside a housing, an additional rain cap is available to protect the air-intake side. Mounting brackets are also available for the filter. Depending on the installation space, brackets for front or rear mounting may be available. For the clean side, pipes made from elastomers and sheet metal are used in conjunction with nozzles, pipe elbows, and flexible hoses made from elastomers.