Engines are used in a variety of different environments, many in areas where high or extreme amounts of dust are present. Dust and other contaminants needs to be removed before the air reaches the engine to prevent premature engine failure. Engines are fitted with air cleaners to remove this contamination from the incoming air. Sometimes the amount of contamination or dirt being removed from the incoming air is so great, the air cleaner reaches capacity very quickly and requires servicing. It is possible to extend this service interval greatly by using a pre-cleaner.
A pre-cleaner is a device which is installed in the intake system of an engine before the air cleaner. It removes most of the contamination and dirt from the incoming air. Pre-cleaners are effective at removing the larger dirt particles and water droplets. As a result, they will greatly reduce the dirt reaching the air cleaner, resulting in extended filter life.
There are many different types of pre-cleaners available. Most of them use some form of inertial separation process to remove dirt without using a replaceable filter.
Dirt particles are heavier than air and will try to continue traveling in the same direction even if the air flow is made to change direction. Effectively, the flow of dirt splits from the flow of air. The heavier the particle, the more effective this process is.
Yes. Apart from the different types of pre-cleaners, all pre-cleaners need the air flow to be moving at a reasonable speed for the separation process to work effectively. If the pre-cleaner is too large for the engine’s air flow, the air will not be traveling quickly enough for the dirt to separate. The dirt will stay mixed with the incoming air. If it is too small, the level of restriction of the intake system will be too high for the engine.
Strata tubes are often used as an integral part of air cleaners used in high dust environments but are also available in a newer type of pre-cleaner called a Strata Cap. These contain small, vaned tubes that cause the air to spin very rapidly. These operate at a very high 95% efficiency, however they need to be used in conjunction with a scavenge system such as an exhaust ejector to clear away the separated contamination.
This all-metal pre-cleaner is a durable solution for punishing conditions. TopSpin HD will extend primary air filter life, boost system efficiency and extend engine life in medium to heavy dust environments. TopSpin HD is self-scavenging and operates at up to 80% separation efficiency.
This style of pre-cleaner works in a similar way to Full View except they are self emptying. Working at up to 85% efficiency, they have a rotating vane that expels the separated dust out the side of the pre-cleaner. While the TopSpin can be used on high speed vehicles, when used at highway speeds there will be an increase to the level of incoming air restriction. TopSpin pre-cleaner is best suited to slower moving and stationary equipment.
Full View Pre-Cleaners
Full View pre-cleaners have angled vanes that cause the incoming air to spin rapidly around the pre-cleaner. Dirt and water is collected in the outer bowl, while the cleaner air passes down the center of the unit to the air cleaner. Once the bowl is full it needs to be emptied. Full view style pre-cleaners operate at about 75% efficiency, and are suitable in low speed and stationary applications. While they can be used on high speed vehicles, full view pre-cleaners will increase the level of restriction to the incoming air.
Often used as a second pre-cleaner for on-highway vehicles, these are effective at removing larger dirt particles and water at faster speeds. They have a set of vanes that cause the air to spin as it passes through the unit with the cleaner. Dryer air continues onto the air cleaner, with the dirt and water being expelled. Inline separators do not requrire scavenge air flow.
The Donaspin™ extends the life your air filter by removing up to 90% of the dirt and contaminant before it reaches the filter and ejecting it automatically via the exhaust system. Donaspin requires an exhaust ejector and is designed especially for equipment operating in very heavy dust/debris environments.
Air Rams are the simplest form of pre-cleaner and is effective in removing dust and water at high speeds and is most suited to highway operation. They have the added advantage of reducing restriction to the air system at high speeds, however it is important that they are installed correctly. Air rams are ineffective at low speed and on stationary equipment.
Pre-Cleaners are a great way to extend your filter life, but they are not a substitute for an air cleaner. They must not be used in place of an air cleaner.