Scavenging Drain Analysis (SDA)

NIPPON YUKA KOGYO >>Scavenging Drain Analysis (SDA)

Scavenging Drain Analysis (SDA)
Cost-saving by optimizing cylinder oil feed rate and prevention of cold corrosion.

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. Detects the abnormal abrasion of cylinder liner, a sign of the blow through, and occasion of the piston rings visually / numerically.
  2. Helps to save the cost by optimizing the cylinder oil feed rate and extending the life of machinery parts.
  3. Ensures sealing performance of stuffing ring by calculating mixing ratio of system oil contained in the scavenging drain oil and prevents the system-oil-contamination.

Benefits

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.

CYLINDER LINER CONDITION

NORMAL CONDITION

COLD CORROSION

ANALYSIS RESULTS
Fe in cylinder drain →
higher than the control range
BN in cylinder drain →
lower than the control range

POSSIBLE RISKS
Wear of cylinder liner and piston rings Low neutralizing-capacity against acid

Detects a sign of cold corrosion and abnormal conditions

 

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"

Ship can reduce the cylinder oil feed rate / consumption safely !!

 

An example of calculation for cost-saving

Navigate: 200days/year
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
Cylinder oil consumption : 73,432 ltrs / year

if CFR 1.40g/kWh would be reduced to
1.20g/kWh...

Cylinder oil consumption : 62,942 ltrs / year

Cylinder oil saved : 10,490 ltrs / year

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.