Tuesday, May 8, 2018

Calculation of Fuel Oil Separator

Fuel Oil Separator image
 
GENERAL
The fuel cleaning process is designed to overcome the harmful effects of fuel oil contaminants, primarily water, water soluble salts, and solid particles.  
From DNV-GL rule, Fuel oil separators shall comply with the relevant requirements.
- Class rule of ships RU SHIP Pt.4 Ch.6

The Fuel oil separators shall be so designed that they will remove an acceptable percentage of the particles (cat fines) in the fuel oil at the certified flow rate. To estimate the ability to remove particles, the separator shall be tested by using a standardised test rig and test medium composed of an unambiguous mixture of synthetic oil and spherical particles.

The separator shall be fitted with necessary monitoring, shut-down and safety functions to prevent critical operational conditions.
The material used shall be resistant to all applicable fuel oil characteristics. Metallic materials shall be used in parts containing oil.


FLOW RATE CAPACITY
However, in this time we will talk about flow rate capacity of separator that relevant to Main Engine.

The required flow rate (Q) can be roughly determined by the following equation:



Where :
Q (l/h)           = Separator  Flow rate
P (kw)            = Total Engine output
be (g/kWh)        = Fuel consumption
ρ (g/l)           = density at separating temp. (approx. MDO at 870 g/l, HFO at 930 g/l)

With the evaluated flow rate, the size of the separator has to be selected according to the evaluation table of the manufacturer. The separator rating stated by the manufacturer should be higher than the flow rate (Q) calculated according to the above formula.

By means of the separator flow rate, which was determined in this way, the separator type, depending on the fuel viscosity, is selected from the lists of the separator manufacturers.

For determining the maximum fuel consumption (be), increase the specific table value by 15 %.

This increase takes into consideration:
▪ Tropical conditions
▪ The engine-mounted pumps
▪ Fluctuations of the calorific value
▪ The consumption tolerance

The freshwater supplied has to be treated as specified by the separator.


Hopefully helpfully 😊
marinengcalc.blogspot.com


No comments:

Post a Comment