According to John Gaither, director of Heavy-duty Engineering, Luber-finer, precleaners are able to remove the majority of the bigger particles (usually 30 micron or larger) found in the air flow. “In conditions with high airborne dust concentrations, a precleaner will remove the most massive particles before they have a chance to build up on the air filter,” he says. “Keeping [larger particles] away from the air filter increases service intervals and overall system efficiency.”
Precleaners are able to separate and remove 75% to 96% of incoming dust and debris from the air, says Anderson. Because they can remove so much of the initial particulate that can get trapped in air flows, precleaners have been shown to increase filter life up to 20 times. A precleaner’s ability to capture higher amounts of large particulate pieces makes it well suited for use in off-highway equipment working in high-dust environments.
The greater a precleaner’s efficiency, Anderson adds, the smaller an air filter can be, which is especially important for vehicles with space limitations.
Tighter Space constraints
One of the biggest challenges for air filter manufacturers is creating a filter that will fit into the ever-tightening space allotments of vehicles and equipment. In the past, the air filter was simply mounted to the top of the hood or close to where the engine was located. But with today’s more streamlined designs, filters are being placed under the hood where space is at premium.
“It’s always a challenge to be able to make an air cleaner smaller, yet still accommodate the high air flow rates required by the engines,” says Wake.
The implementation of Tier 4 engine systems has reduced available space due to the larger cooling and exhaust aftertreatment systems the engines require. The space constraints have prompted air filter manufacturers to focus their research and development efforts on creating technologies that can fit into the smaller machine footprints while still providing the same, or better, filtration performance.
For its PowerCore filtration technology, Donaldson was able to design compact yet efficient air filters that can reduce the air intake system size by 60%, says Anderson.
The use of plastic housings for filters is becoming more prominent within the filtration industry. Both Wake and Anderson say the shift away from metal housings is due to the weight and cost savings plastic can provide.
However, the choice of housing material depends on the application in which the filter will be used. While a plastic housing can offer weight savings, a metal housing can be more beneficial for severe-duty applications, where the amount of vibration could affect filter performance if it is not protected by a more durable housing.
Filtration media and how it’s packaged will also be a focus for future research and development efforts. Wake says some companies are moving away from traditional pleated filter media packaging — designed to provide more filter media area — to a fluted arrangement. A fluted design looks similar to a honeycomb, and allows air to flow straight through the filter from one end to the other. “It’s [a way to] package the filter media into the housing to optimize the air flow and the collection of dust, and try to reduce the filter restriction itself... in the smallest package possible,” says Wake.
Overall, improved efficiency and dirt-holding capacity will continue to be the key drivers for engine air filter design now, and far into the future, to ensure optimal engine and vehicle performance.