TFL JUL
16
FREIGHT AND LOGISTICS
FUELS AND FILTERS
TODAY’S ENGINES
use what is called ‘high pressure common rail’ (HPCR) fuel injection
systems that operate upwards of 40 000psi (2800 bar). These systems require very clean fuel
to operate as-designed for their entire service interval. Unfortunately in most cases, new fuel
does not mean clean fuel.
Fuel contamination can be separated into two broad categories: inorganic and organic.
Inorganic contaminant is typically hard particulate (dirt) picked up throughout distribution.
From the refinery, fuel is typically clean, but as it gets transported throughout distribution
(which can include pipelines, terminals, and delivery trucks) it becomes increasingly dirty. Once
onsite, as it’s stored in bulk tanks and moved for distribution and use, it picks up contaminant
from the infrastructure as well as ambient conditions.
Organic contaminant represents anything carbon-based, typically longer hydrocarbons with
various chemicals attached.These organic contaminants can come from a variety of sources at,
or downstream from, the refinery, including: lubricity improvers; cold flow improvers; biodiesel;
corrosion inhibitors, etc. It is important for fuel additives to be dosed at the correct levels and
under the right conditions to ensure the best overall fuel stability, otherwise additives can
become insoluble and therefore ‘filterable’.
Generally speaking, hard particulate (inorganic contaminant) will cause permanent damage to
the injector system, while softer particulate (organic contaminant) will cause fouling, namely,
deposits build up on the injectors. In both cases the engine does not run as-designed and
can result in a decrease in fuel economy, an increase in emissions, and a decrease in power.
Most fuel is delivered to storage tanks 500 to 1000 times dirtier than what is allowed in
these injection systems. Traditionally, only on-engine filters would be used to remove the
contamination in the fuel to meet injection system fuel cleanliness specifications, but the
requirements for HPCR fuel are so high, that a two-step approach is needed to achieve
consistent cleanliness: first filter fuel in the bulk storage tank, prior to use in the equipment
and then with the on-engine filters.
Bulk filters should remove contamination in the fuel down to a cleanliness level of ISO
14/13/11, whether the contaminant present is hard or soft. It should be noted however, that
all fuel filters are designed with the goal being to remove the hard inorganic particles, so
while they will also filter the soft organic materials, life may be greatly reduced in comparison.
Besides meeting HPCR fuel cleanliness requirements, the use of bulk filtration also provides the
necessary protection against any highly contaminated fuel that may be delivered (ongoing or
as a one-time occurrence). By filtering prior to use in the equipment, the bulk filtration system
will stop excess organic and inorganic particulate from being delivered into your equipment’s
tanks, ensuring the onboard filters can meet the expected service intervals. If a fuel problem
should exist, it may plug up the bulk filters, but not the on-engine filters. This eliminates costly
unscheduled downtime and makes operation and maintenance much more predictable.
Today’s engines are more sophisticated and require cleaner fuel than before. Investing in a
bulk fuel filtration system will protect your equipment against dirty fuel, eliminate unplanned
downtime, and keep you running optimally.
The need for
clean fuel
in
new engine technology
By
Deena Kasavelu,
Sales Manager – Donaldson Clean Fuel & Lubricant Solutions
Welcome to the Clean Fuel
Corner. This column is an
opportunity to learn more
about how evolving diesel
engine technology is driving
the need for cleaner fuel.
While that may seem to
be fairly straightforward,
delivering clean and dry fuel
consistently to the engine’s
fuel injection system can be
a challenge. On a monthly
basis we’ll explore these
challenges and how they
can be overcome, with a
focus on handling fuel prior
to being pumped into the
vehicle. Written from the
angle of a global filtration
company, the focus will be
on the role of filtration in
achieving the necessary OEM
specifications, but we’ll also
mix in some important info
on other topics like storage
tanks, pumps and engines.
CLEAN
FUEL
CORNER
