3.2
Treatment of detergent type
lubricating oils
3.2 Treatment of detergent type
lubricating oils
? The main function of detergent lubricating oil is
to keep solid contaminations in suspension and
prevent both their agglomeration and deposition
in the engine.
? This function reduces ring sticking,wears of
piston rings and cylinder liners,and generally
improves the cleanliness of the engine.
agglomeration
3.2 Treatment of detergent type
lubricating oils
? Other functions include reduction of lacquer
formation,corrosion and oil oxidation.
? These functions are achieved by the formation of
an envelope of detergent oil round each particle
of solid contaminant.
? This envelope prevents coagulation and
deposition and keeps the solids in suspension in
the oil.
lacquer coagulation
3.2 Treatment of detergent type
lubricating oils
? In engines of the trunk piston type with a combined
lubrication system for bearings and cylinders,in addition
to the deposition of the products of incomplete
combustion which occurs on pistons,piston rings and
grooves,some of these products can be carried down into
the crankcase,contaminating the crankcase oil and
causing deposition in oil lines,etc.
? Detergent oils are,therefore,widely used in this type of
engine.
3.2 Treatment of detergent type
lubricating oils
? The detergent additives used today are,in
most cases,completely soluble in the oil.
? There may,in certain instances,be a
tendency for the detergent to be water
soluble,or for emulsion to be formed,
particularly if a water-washing system is
incorrectly used during separation.
3.2 Treatment of detergent type
lubricating oils
? Manufacturers of centrifuges have carried out a
considerable amount of research work in
conjunction with the oil companies on the
centrifuging of detergent lubricating oil using
three different methods of centrifuging,i.e.,
purification,clarification and purification with
water washing.
3.2 Treatment of detergent type
lubricating oils
? The following is a summary of the findings and
recommendations based on results which were
obtained:
– When operating either as a purifier (with or without
water washing) or as a clarifier all particles of the
order of 3 - 5 microns and upwards are completely
extracted,and when such particles are of high specific
gravity,for example iron oxide,very much smaller
particles are removed.
3.2 Treatment of detergent type
lubricating oils
– The average size of solid particles left in the oil
after centrifuging are of the order of only l - 2
microns (One micron is a thousandth part of a
millimeter).
– No particles are,therefore,left in the oil which
is of sufficient size to penetrate any oil film in
the lubricating-oil system.
penetrate
3.2 Treatment of detergent type
lubricating oils
– A centrifuge should be operated only with the
bowl set up as a purifier when the rate of
contamination of the lubricating oil by water is
likely to exceed the water-holding capacity of
the centrifuge bowl between normal bowl
cleanings.
Set up as
3.2 Treatment of detergent type
lubricating oils
– When the rate of water contamination is negligible,
the centrifuge can be operated with the bowl set up as
a clarifier,
– Any water separated will be retained in the dirt-
holding space of the bowl,
– Purification with water washing can be employed to
remove water soluble acids from the oil,in addition
to solid and water contaminants,
– This method can be used with most detergent
lubricating oils but it should not be used without
reference to the oils suppliers,
3.2 Treatment of detergent type
lubricating oils
– Normally it is not desirable to water wash detergent
oils because one of their functions is to prevent the
formation of acid in the oil.
– If it is decided to use water washing the quantity of
wash water used must be strictly limited and should
not be in excess of 1 per cent of the oil flow.
– If too much water is used emulsion troubles may
occur.
Treatment of detergent type
lubricating oils
3.2 Treatment of detergent type
lubricating oils
? The main function of detergent lubricating oil is
to keep solid contaminations in suspension and
prevent both their agglomeration and deposition
in the engine.
? This function reduces ring sticking,wears of
piston rings and cylinder liners,and generally
improves the cleanliness of the engine.
agglomeration
3.2 Treatment of detergent type
lubricating oils
? Other functions include reduction of lacquer
formation,corrosion and oil oxidation.
? These functions are achieved by the formation of
an envelope of detergent oil round each particle
of solid contaminant.
? This envelope prevents coagulation and
deposition and keeps the solids in suspension in
the oil.
lacquer coagulation
3.2 Treatment of detergent type
lubricating oils
? In engines of the trunk piston type with a combined
lubrication system for bearings and cylinders,in addition
to the deposition of the products of incomplete
combustion which occurs on pistons,piston rings and
grooves,some of these products can be carried down into
the crankcase,contaminating the crankcase oil and
causing deposition in oil lines,etc.
? Detergent oils are,therefore,widely used in this type of
engine.
3.2 Treatment of detergent type
lubricating oils
? The detergent additives used today are,in
most cases,completely soluble in the oil.
? There may,in certain instances,be a
tendency for the detergent to be water
soluble,or for emulsion to be formed,
particularly if a water-washing system is
incorrectly used during separation.
3.2 Treatment of detergent type
lubricating oils
? Manufacturers of centrifuges have carried out a
considerable amount of research work in
conjunction with the oil companies on the
centrifuging of detergent lubricating oil using
three different methods of centrifuging,i.e.,
purification,clarification and purification with
water washing.
3.2 Treatment of detergent type
lubricating oils
? The following is a summary of the findings and
recommendations based on results which were
obtained:
– When operating either as a purifier (with or without
water washing) or as a clarifier all particles of the
order of 3 - 5 microns and upwards are completely
extracted,and when such particles are of high specific
gravity,for example iron oxide,very much smaller
particles are removed.
3.2 Treatment of detergent type
lubricating oils
– The average size of solid particles left in the oil
after centrifuging are of the order of only l - 2
microns (One micron is a thousandth part of a
millimeter).
– No particles are,therefore,left in the oil which
is of sufficient size to penetrate any oil film in
the lubricating-oil system.
penetrate
3.2 Treatment of detergent type
lubricating oils
– A centrifuge should be operated only with the
bowl set up as a purifier when the rate of
contamination of the lubricating oil by water is
likely to exceed the water-holding capacity of
the centrifuge bowl between normal bowl
cleanings.
Set up as
3.2 Treatment of detergent type
lubricating oils
– When the rate of water contamination is negligible,
the centrifuge can be operated with the bowl set up as
a clarifier,
– Any water separated will be retained in the dirt-
holding space of the bowl,
– Purification with water washing can be employed to
remove water soluble acids from the oil,in addition
to solid and water contaminants,
– This method can be used with most detergent
lubricating oils but it should not be used without
reference to the oils suppliers,
3.2 Treatment of detergent type
lubricating oils
– Normally it is not desirable to water wash detergent
oils because one of their functions is to prevent the
formation of acid in the oil.
– If it is decided to use water washing the quantity of
wash water used must be strictly limited and should
not be in excess of 1 per cent of the oil flow.
– If too much water is used emulsion troubles may
occur.
