The regulations regarding discharge of oily water in oceans are becoming stricter year after year. It is for this reason that marine oil water separators have become compulsory for every type of ship. The oily water separators are used in treating the oil-water mixture coming from the bilge spaces, compartments on the ship or oil tanks which have accumulated water before totally discharging it on the sea. According to a regulation made by a regulatory board, water that is to be discharged on the sea should only contain less than at least 15 parts per million of oil. The oily water separator is used in order to attain this.
Almost every type of oily water separator uses the gravity system when separating water from oil. This particular method will allow the system to bring the parts per million figures to 100 which is still not enough. It is for this purpose that all oily water separators are equipped with a distinct filtration system in order to bring the PPM level down. The parts per million is then measured using an instrument which is similar when working with Salinometer which is in turn used to check salt PPM.
Construction of the separator unit
The separator unit consists of two parts. The first part of the unit consists of a coarse compartment unit which has an inlet for the oil water mixture. The water mixture with oil will then enter the separating compartment through the inlet pipe. Because some of the oil molecules have lowers density, these will immediately separate and then rise to the top of the water and oil mixture towards the oil collecting compartment.
The remainder of the oil will leave the compartment. It will escape the compartment by using an outlet which is provided near the bottom of the chamber towards the second part which is a compartment that separates the particles. The compartment has different stationary catch plates which are arranged at the center of the unit’s compartment. The oil mixture will then flow slowly in between the catch plates. The oil coming from the mixture will then stick to the side of the catch plates and will then move slowly outwards to rise to the top of the oil and water mixture. The oil will then get collected inside an oil collecting space.
The clean and treated water which has a PPM of at least 100 will then be flushed out of the compartment via a pipe which is attached at the center part of the compartment. All of the compartments that collects oil are provided with steam inlets or heating coils for heating the oil in order to facilitate the substance’s free flow. The air that is produced is then released via a vent that is located at top part of the compartment.