The importance of oil water separator system in marine operations
It ensures that ships and other marine vessels do not discharge oil into the ocean. Local and international regulations have become Oil Water Separator System stringent on the release of untreated bilge water in an effort to protect marine life. Clean water that is suitable for discharge should contain less than 15 parts per million of oil. The gravity system which is used for the separation of oil from water can only achieve about 100 parts per million so that the use of a filtration system is advised by experts. Bilge water is part of a ships operation but oil coming from generators, air compressors and the propulsion engine can contaminate water. Aside from oil, water must be cleared of all contaminants before it is allowed to be discharged into the ocean otherwise it can be harmful to marine life.
How the oil water separator system works
It can only be operated when the ship is sailing and when en route. The equipment consists of catch plates placed inside a coarse separating compartment and an oil collecting chamber. Since oil has a density that is much lower than water, it rises to the oil collecting compartment while the rest of non-flowing oil mixture will settle down into a fine settling compartment after passing between the catch plates. After a certain period of time has passed, more oil will separate which will be collected in the oil collecting chamber. Oil content of water as it passes this stage will be 100 parts per million of oil. A pneumatic control valve will release oil that has been separated from water into a designated OWS sludge tank. Modern OWS sludge tanks include an alarm and automatic closure device that activate when the oil storage content of wastewater exceeds the limit.
The filtration unit is separate from OWS. The filtration unit consists of the filter stage, coalesce stage and collecting chamber. The filter stage separates impurities so that they can settle at the bottom for collection. The second stage includes the process of coalescence where oil droplets are joined to increase their size. When large oil molecules rise at the top of the water, they can be easily removed. The output from the filtration should satisfy the discharge requirements of MARPOL where water contains 15 parts per million of oil. If the oil content exceeds the allowed limits, maintenance work must be undertaken like filter cleaning or the replacement of filters.