SsangYong Stavic / SsangYong Rodius (2005 year). Manual — part 111
DI04-37
CHANGED BY
EFFECTIVE DATE
AFFECTED VIN
EXHAUST SYSTEM
DI ENG SM - 2004.9
Mat
Insulation
Cover
Upper part of
converter
Plate
Monolith catalyst
Lower part of
converter
Inlet gas
Outlet gas
System and principle
Oxidation catalytic technology for diesel engine is basi-
cally the same with it of gasoline engine used before de-
velopment of 3 primary catalyst (2 primary catalyst), and
its effect and performance were already proved.
DOC (Diesel Oxidation Catalyst) reduces HO and CO con-
tained exhaust gas over 80 %, and removes SOF (Soluble
Organic Fraction) over 50 ~ 80 %, but because its portion
in total PM is low, it reduces approx, 20 ~ 40 % of TPM
(Total Particulate Material).
Because of low reducing rate for PM of DOC, in order to
guarantee safety rate of PM regulation, this technology is
being used mainly. And it should keep over 80% of PM
reducing rate, and at present it plays a role as a transition
stage.
And also it reduces diesel odor and black smoke, plati-
num or palladium are being used as a catalyst.
On the other hand, it is a problem that it makes the reac-
tion of oxidation, which SO
2
produce SO
3
and H
2
SO
4
by
reacting to oxygen in exhaust gas, if temperature of ex-
haust gas becomes over 300°C, and this produced gas is
very harmful to human body. To prevent is, previously it is
requested that the sulfur content rate of fuel should be
below 0.05 %, and in the future it is being expected to
keep it below 0.01 %.
Catalytic converter structure
The Catalytic converter of monolith type consists of 2 walled
metal bodies which is made of Cordierite.
The principal element of converter consists of the materi-
als like Alumina or oxidized Serume in order to apply to
Ceramic Monolith. Washer coat operates first, and cata-
lytic metal elements (Pt, Pd, Ph) operates to washer coat
next.
Monolith type is lighter than other types, easy to manu-
facture and quickly approaches to proper temperature.
Washer coat is used to make a contact surface with ex-
haust gas bigger by adhering closely to small holes of
inner layer.
If a lead compound or phosphorus adheres to the surface
and the temperature rises, its surface is decreased.
The total area of general monolith converter is about
45,000 ~ 500,000 ft
3
. (10 times of a football field)
Generally Alumina (AL
2
O
3
) is used as a raw material and
its 7 phases of gamma, delta, theta have big areas and
high stability for the temperature, and nowadays gamma
Alumina is used usually.
DOC (Diesel Oxidation Catalyst)
DI04-38
CHANGED BY
EFFECTIVE DATE
AFFECTED VIN
EXHAUST SYSTEM
DI ENG SM - 2004.9
Purification of catalytic converter
• Adhesion of soluble organic fraction (SOF) below 180°C
• Purification of soluble organic fraction (SOF) over 180°C
Chemical reaction formula
• SOF(HC) + O2 . . . ... O2 + H2O
• 2CO + O2 . . . . . .. 2CO2
• 2C2H6 + 7O2 . . . . . 4CO2 + 6H2O
Catalytic converter and temperature
Catalytic converter has the normal function of purification at a
range of the temperature. Because it has a weak point of de-
creasing of the purification rate in the condition of continuous
high temperature, it should keep the temperature range of 400
to 500°C for normal condition. HC purification rate becomes
better according to the increase of temperature in the normal
range of temperature. CO purification rate becomes the best
near the temperature of 450°C, and NOx does so near the
temperature of 400 to 500°C.
• Oxygen adheres to catalytic material : below 180°C
Aldehide
Aromatic HC
Catalytic Material
Catalytic Material
DI04-39
CHANGED BY
EFFECTIVE DATE
AFFECTED VIN
EXHAUST SYSTEM
DI ENG SM - 2004.9
• Catalytic material supplies each CO and HC with O2 for
their oxidation : above 180°C
Catalytic Material
Catalytic Material
PAH (Aromatic HC)
Catalyzer
• Catalytic material conversion process by DOC
Method for reduction of NOx
NOx is generated a great deal in case that combustion tem-
perature and excess air factor are high. EGR valve can de-
crease NOx (30 to 35 % decrease) by making temperature of
combustion chamber fall by means of exhaust gas re-
circulation.
DI04-40
CHANGED BY
EFFECTIVE DATE
AFFECTED VIN
EXHAUST SYSTEM
DI ENG SM - 2004.9
Exhaust Pipe
- Removal and Installation
1. Remove the upper bolts at turbo charger.
Notice
Use the universal type wrench.
2. Remove the lower bolts and gasket.
3. Remove the #1 hanger.
4. Remove the #2 hanger.
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