NIPPON YUKA KOGYO >>Scavenging Drain Analysis (SDA)
What is SDA ??
Scavenging Drain Analysis (SDA) is a major oil analysis to estimate the iron (Fe) content and residual alkali (BN) content in the cylinder drain by analyzing the scavenging drain and system oil.
It can help to determine the condition of the piston rings and the liner visually / numerically, as well as calculating the mixing ratio of system oil contained in the scavenging drain.
1. Early detection of COLD CORROSION
Cylinder liner and piston rings in Ship's main engine are in the risk of corrosion caused by H2SO4 (sulfuric acid),which comes from the reaction with sulfur content in the combustion gas and water.Besides, troubles by cold corrosion have been reported due to the slow steaming operation and technological /advanced type of main engine nowadays.
NORMAL CONDITION
COLD CORROSION
ANALYSIS RESULTS | |
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Fe in cylinder drain → higher than the control range |
BN in cylinder drain → lower than the control range |
POSSIBLE RISKS | |
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Wear of cylinder liner and piston rings | Low neutralizing-capacity against acid |
2. COST-SAVING obtained by SDA
Cylinder oil is normally "overfed" to the system due to the concern - abnormal wear down of cylinder liner and piston rings. a "visualized condition" by SDA successfully assists reducing cylinder feed rate safely, results insaving cost for cylinder oil consumption..
ANALYSIS RESULTS | |
---|---|
Fe in cylinder drain → lower than the control range |
BN in cylinder drain → higher than the control rang |
CONDITIONS | |
---|---|
Low risk of cylinder liner and piston rings wear | Neutralizing-capacity against acid has "safety allowance" |
Navigate: | 200days/year |
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Ave. engine load: | 10,180kW |
Density of cylinder oil: | 0.9316g/㎤ |
Cylinder oil feed rate: | 1.40g/kWh |
Cylinder oil price: | US$1.30/ltrs |
Currency: | US$1.00/JPY 112 |
if CFR 1.40g/kWh would be reduced to
1.20g/kWh...
10,490 ltrs (oil saved) ×US$1.30 / ltr (price) = US$13,637 / year (cost saved)
Above example shows that optimizing the cylinder oil feed rate with Scavenging Drain Analysis results in cost-savingby reducing cylinder oil consumption safely and helps to extend the life of the cylinder liners and piston rings.