Centrifugal
Filtration
AEI
has a long history with handling lubricant oil soot issues in
diesel engines. High levels of soot in the oil can lead
to extensive problems with engine wear. One of the
primary reasons for establishing shorter oil drain intervals
was the need to control the total soot concentration in the
oil and prevent engine durability issues. Oil soot
became a major problem in heavy duty diesel engines in the
late 1980’s, when the levers used to lower NOx emissions had
simultaneous negative effects by increasing lubricant soot.
To address the
lubricant soot issue, AEI has developed an instrument called the
BTSA that is used worldwide by engine OEM’s to develop new
ratings. AEI also began researching a filtration mechanism for
removing soot from the oil. The commercially available barrier
filter media was not a good solution, because the soot particles
were extremely small relative to the filtration media pore size.
If the media was made tight enough to trap soot, it woul d
plug very quickly. This was a problem on both commercial and
military vehicles. The centrifugal filters that existed were
based upon a hero turbine mechanism, and could not spin fast
enough to create the gravitational
forces necessary to separate soot particles, due to the very small
difference in particle density.
AEI developed some
prototype filters based on high speed centrifugal filtration.
Soot particles have a slightly higher density than oil, thus under
an extremely high gravitational field, the soot could be made to
separate from the oil. Based on the research results from these
prototype filters, AEI was awarded a contract with the US Department
of Defense towards the development of a centrifugal filter that
would greatly extend the intervals between oil changes and
potentially provide a lifetime filtration system for certain
vehicles.
Two different types of
rotational drive mechanisms were developed, one based on an
auxiliary oil-powered turbine and the second based on an electric
driven brushless DC motor. These technologies have been tested on
customer engines in test cells and on vehicles with excellent
results.
AEI owns and has full assignment of eight issued patents in
conjunction with these technologies. Additional patents are
pending.
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