ROD AS 2066662 - Caterpillar

Single Stage Air Cleaner (Air Filter)
A single stage air cleaner does not have a precleaning feature designed into the housing. This air cleaner typically has a primary and a secondary elements. Single stage air cleaners are commonly used for low dust applications.Two Stage Air Cleaner (Air Filter)
A two stage air cleaner contains a precleaning feature. The precleaning feature is typically designed into the housing. This design allows the incoming air to spin in the housing, which causes the separation of the large particles before the air enters the filter element. The large particles are then discharged from the housing through a built in discharge port. Typically, the two stage air cleaner has primary and secondary air filter elements. Two stage air cleaners are commonly used for high dust applications.Precleaner
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Example of a precleaner
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Example of a plenum that connects the precleaner to the filterA precleaner can be separate or integrated into the air cleaner. The precleaner is designed to clean the intake air before the air flows through the primary filter element. Precleaners extend the life of primary filter elements by removing large particles of dust and dirt before the particle reach the primary filter element. There are two main types of precleaners, turbine and separator tube. Use of a built-in dust discharge port in the precleaner housing is recommended in order to limit dirt accumulation and maintenance.Turbine precleaners use a rotating impeller to separate primarily large particles from the airstream. The rotating impeller forces most of the larger particles towards the outer edge of a single inlet airstream. The particles are then discharged through a diverter feature built into the edge of the housing. Turbine precleaners do not typically require scavenge, although the turbine performance can be enhanced if scavenge can be used.Separator tube precleaners use specially designed tubes to separate large and small particles from the airstream. Separator tube precleaners use several smaller fixed vane cyclonic tubes to force the dirt particles out of the divided airstreams by centrifugal motion. The dirt particles are then discharged through gravity fed or vacuum driven scavenge port.Precleaners can be used with single or with two-stage air cleaners. However, the use of precleaners with two stage air cleaners is not generally recommended. Housing
Air filter housings can be metallic, non-metallic, or a combination. Housings can have various shapes and sizes. Air filter housings are designed to be vibration, corrosion, chemical, and impact resistant. Filter housings should be designed to fit the machine or engine application. The filter element is designed to fit precisely into the housing to ensure a good seal so that only clean air enters the engine.Primary Filter Element
The primary filter element is designed to remove the dirt from the airstream before entering the engine. The primary filter element media may be synthetic, cellulose, or a combination. Filter media may also contain resins and binders. The media could be of various designs including but not limited to pleated and fluted. A high-quality filter media allows high separation efficiency and