10 Important Factors for Oil Water Separator Operation On Ships

Optimal performance of the Oil Water Separator depends on the knowledge of certain factors like design, operation, bilge management and maintenance etc. In this article we shall discuss the varied operational factors influencing performance of the Oil Water Separator.
Operational Factors
Correct operational knowledge is required for all machinery on ships to run properly and therefore the Oil Water Separator  is not any exception. Marine engineers work with differing types of Oil Water Separators through their sea career and every type has its own unique features.

Equipment specific knowledge is important for the right operation of Oil Water Separator and may be learnt from the operational manual on board. However, a generic knowledge is additionally required because the basic working rule is actually an equivalent.
An idea taken from existing shore technology, the Oil Water Separators for ships are designed to identify properly under ideal conditions. However, ships don't have ideal conditions, and thus ship’s staff should consider the subsequent operational factors which affect the performance of Oil Water Separator on ships.

1. Avoid Emulsions: Emulsions are formed when the inter-facial tension between two liquids is reduced by certain means sufficiently to permit droplets of 1 liquid to disperse in another. Mechanical agitation, shearing forces, solvents, chemicals, surfactants and therefore the presence of particulate can all reduce inter-facial tension and end in formation of emulsion.

2. Avoid Chemical emulsions: The chemical emulsion is made by the addition of some chemicals within the water. These chemicals act as surfactants and that they hold the oil drops together in emulsified state. The surfactants could also be the detergents used for cleaning, alkaline chemicals used for boiler cleaning and conditioning etc.

3. Avoid secondary diffusion: Mechanical mixtures are of first and second types. the first emulsions are larger drops of oil dispersed in water and are generally separated within 24 hours. The secondary emulsions are fine droplets of oil that are thermodynamically stable and don't separate. The secondary dispersion is caused by turbulent conditions.

4. Avoid suspended solids: Suspended solids cause steadiness of emulsion and create complications in separation of the oil from the bilge water. Suspended solids are often mud, boiler soot and cargo residues sucked from the blowers. The suspended solids get coated with oil and stabilize the emulsion. Neutrally buoyant solids that neither rise nor fall are most troublesome because it is difficult to get rid of them. They also generate the high ppm alarm.

5. Avoid Turbulence: OWS needs streamline flow to work optimally as per their design. Avoid using OWS in times of heavy rolling and keep all line valves fully hospitable avoid generating turbulence. Sometimes thanks to turbulence a number of the oil droplets subsided than 8 microns and are suffering from the random motion of the water particles. This random motion is named as Brownanian motion and it nullifies the forces of buoyancy and therefore the oil drops fail to rise.

6. Avoid Particulate Matter: Fine particulate like soot, rust, microbial contamination of bilge water etc. also act as emulsifying agent. Although most of the soot of the boiler washing settles down within the bilge holding tank, fine soot particles (1μm or less) will give the bilge water a blackish appearance. These particulate won't only fool the ppm meter into activating the high ppm alarm but also will physically act as emulsifying agent

7. Optimal use of Chemicals: Sometimes it's required to use special chemicals called emulsion breakers to separate the oil from the water and release free oil.

8. Restrict Drainage of Chemicals: Lot many chemicals are utilized in engineering for special purposes like water conditioning, corrosion inhibition, rust removal, cleaning, degreasing etc. However, care should be taken to gather these chemicals and disposing them properly. Allowing all quite chemicals to run free into the bilges isn't good housekeeping.

9. Avoid prolonged storage: Prolonged storage of the bilge water causes modification within the nature of free oil. Normally oil water mixture when allowed to face for a few time (say 24 hours) separates into a layer of oil on top of water called as free oil. This free oil is straightforward to get rid of but long retention of the bilge water can cause modification within the properties of free oil thanks to oxidation and microbial action. If this modification occurs then it's difficult to get rid of the oil.
10. Do Proper Filtration: If there's great deal of solid particles, floating media, jute etc. within the bilge water, it should be properly removed using strainers to avoid fouling of the filter media.