Separator Performance

One effective way to accurately determine oil separator performance is to ask vendors to provide:

• Oil droplet size Vs Separation efficiency curves for the oily water separator being considered. This curve should not be some generic curve but one for the exact conditions for the application. Note that many manufacturers cannot provide such a curve, but the reputable suppliers should be able to do so.

• Ask the vendors if they can carry out performance tests to prove the separation curves provided.

How clean the water will become depends mainly on the nature of the oily water to be treated. Some of the critical oily water parameters for determining the oil separation efficiency of separators are: 

• Oil droplet size

• Oil and water densities

• Oil and water viscosity

In most typical applications the Spinifex Separator can produce a results as follows:

• Less than 10 mg/l oil & grease

• Less than 100mg/l suspended solids

• Less than 30mg/l petroleum hydrocarbons.

In many cases Spinifex can give this guarantee. It is important to note however that for any guarantee to be credible it must contain at least the following information:

• Performance curve of the separator (see above)

• Characteristics of the oily water mixture to be treated (see above).

The term “emulsion” is often used to describe an oily water mixture with a lot of very small oil droplets. However there is no universal definition of what is a “small” oil droplet. It is therefore better not to use this term in performance specifications but to refer back to oil droplet size data curves as mentioned above. Spinifex separators can usually deal quite effectively with oil droplets above 15 micron in size.

Detergents and cleaning agents are often responsible for producing oily water mixtures with a lot of small oil droplets. This makes the separation more difficult for gravity based oil separators but usually does not cause any appreciable loss in oil separation efficiency with Spinifex separators.  

The standard Spinifex modules are only supplied with air operated diaphragm pumps.  The reason for this are explained on the Spinifex Oil separator page. Engineered systems can be supplied with electric pumps.

Cost

Yes. Spinifex has a variety of spreadsheets available for detailed cost comparisons. These spreadsheets allow you, the customer, to enter your own data to determine what option gives the least ownership cost.

Spinifex makes these sheets available at no cost. Simply email your requirements and we will send the appropriate spreadsheet.

Oil Collection Tank  

You will probably not be able to save money in the medium term by using budget oil collection tanks when consideration is given to the following factors:

• Occupational health and safety

• Handling spillage and cleanup

• Site appearance

• Cost of collection

 In addition the Spinifex system needs an oil storage device with automatic water decant and the Spinifex oil tank forms an integral part of the effectiveness of our systems.

Yes. The Spinifex oil collection tank can be fitted with an optional 2” concentrated oil outlet. This outlet can be connected to a smaller waste oil drum.

Debris / Strainers and Blockages  

How often the basket needs cleaning depends on the amount of debris and rubbish collecting in the pit. For most of our installations the basket should be inspected and cleaned about every 6 months, but this can vary.

The strainer basket is installed on the suction side of the pump to protect the system from larger pieces of debris that could potentially block the separator oil outlet (reject orifice) or damage the pump. The mesh size or hole size of our baskets is typically more than 3 mm.

When installed and operated correctly the Spinifex separator never blocks and it never needs cleaning. This is one of the great attractions with the Spinifex system.

Spinifex would recommend a recycle valve and recycle timer when:

• The system is likely to operate very infrequently, say only once per week. In these circumstances there is likely to be a build up of an oil layer.

• The system is in a critical application, like a fuel site where larger oil spills are more likely.

• The site is likely to have large oil spills greater than 200 litres.

• If it was a very difficult separation with say small oil droplets, highly emulsified mixture and recycle was needed to achieve the discharge specification.

• The very clean water is required.

Skimmer

The skimmer removes free-floating oil from the effluent water collection pit. This has many advantages including:

• Keeps the pit free of stagnant, smelly oil layers

• Makes the pit “flood-proof” (minimising any oil spillage should the collection pit accidentally flood)

• Removing the free floating oil also allows any dissolved oil in the water to liberate into the atmosphere instead of being “locked in” by the oil layer.