Designing filtration to protect the world’s largest engines is what Donaldson, the filtration specialist, does. These diesel behemoths, whose working environment is the rugged, persistent dust and dirt sites of the mining and heavy construction industries, represent some of those sectors’ largest capital investments. Donaldson’s leading-edge technology more than meets the filtration requirements of these vehicles in every key area – air, lube, fuel, coolant and hydraulic.
One of the biggest challenges on high dust and sand particulate sites is the avoidance of engine dust ingestion. Designed with this in mind, the SRG Donaclone air cleaner stands at the top of the Donaldson S Series lineup. The SRG features a two-stage design. The first stage is that where the incoming air is pre-cleaned and consists of patented Donaclone pre-cleaner tubes, with over 130 tubes in the SRG 20 and over 250 tubes in the SRG29 units. As the incoming dustladen air makes contact with the vanes in the Donaclone tubes it starts a cyclonic twist with a centrifugal force that separates up to 95-97% of the dust and dirt in the air stream, allowing it to fall into a dust cap.
Since it is the air that spins, not the Donaclone tubes themselves, there are no moving parts in the filter unit, so there is nothing to break down or maintain beyond periodic cleaning. The tubes perform their function whenever the engine is running and the dust from the pre-cleaner stage is automatically ejected from the dust cup through the vacuator valve located below the Donaclone tubes.
This leaves a much lighter task for the second filtration stage, which is itself broken into two stages comprised of a primary and safety filter.
The safety filter’s key function is to prevent any service dust entering the clean air side on removal of the primary filter during filter change-out or incorrect fitment of primary element (i.e. loose wing nut). Incoming pre-cleaned air first must face the large Donaldson primary filter and then the safety filter. The Donaclone pre-cleaning efficiency in the SRG and STG air cleaners means fewer stops for air filter servicing in environments where airborne particulate is hostile to engines. Additionally, longer filter cartridge life can be anticipated as well as the main prize – extended engine life.