PRODUCT INFORMATION
INDEX
DATE
Dep. 2
IC-C-D-35-001e D
September 2016
AIR FILTERS
1/4
1. AIR FILTERS. CHARACTERISTICS
It is the function of an air filter to ensure that air supplied to the engine has optimum cleanness characteristics.
Kohler
engines can include either of two types of filters: double-stage cyclonic filters and GHF high-flow
single-stage filtration filters. The cyclonic air filters used on
Kohler
engines comprise two filtering elements or
cartridges: one so-called main cartridge outside and the other so-called safety element inside. High-flow filters
are single-stage filtration systems.
Air filtering is achieved to global efficiency rates of 99.7%. Pressure losses due to filtering are less than 20mbar
with a clean filter and the engine running at rated power and full speed. Filter plugging occurs when pressure
losses exceed 38mbar.
The air filters fitted to
Kohler
engines can be used in dust-laden atmospheres of up to 15 mg/m
n
3
. In case of
greater dust concentration, it will be necessary to install mechanical air prefilters (refer to document
IC-G-D-35-001e).
In double-stage filters, this is how filtering occurs:
-
Air enters the filter tangentially to the cylindrical casing of the filter.
-
Passes through the first filtering element (main element).
-
Flows through the second, safety filtering element.
-
And finally goes out axially with respect to the filter casing.
Fig. 1 - General view of double-stage air filters
The airflow restriction created by the air filters increases as the filters get fouled.
As already mentioned, the maximum permissible airflow restriction is 38mbar for
filters on engines running at their power rating. On reaching this value, the
filtering elements are said to be clogged and must be immediately cleaned or
changed. For monitoring their fouling level, the
Kohler
filters include a
mechanical air flow restriction detector Ref. 76.50.134 with a red-coloured
indicator showing up completely when the maximum permissible pressure drop
has been reached. Alternatively, an electric detector Ref. 76.50.321 can be
installed, indicating the fouling condition of the filters by means of a light signal
or by transmitting an electric signal to the PLC.
Main
Safety
Fouled
filter
2.6.5
O&M_2.002211.810_A_10_2016
