Maintenance

• Many oily water separators, such as the plate pack type require regular cleaning and maintenance to continue functioning. It is important for customers to fully understand cleaning and maintenance requirements before committing to a purchase.
  
  Typical Cleaning periods

• Plate pack; also known as Corrugated Plate Separators (CPS), Vertical Gravity Separators (VGS), Tilted Plate Interceptors (TPI); Typically every month

• API and Gravity Pits: De-sludge and clean perhaps twice per year

• Ultraspin Separators: Typically every 4 to 6 months

To accurately determining the 'real" cleaning and maintenance requirements for oily water separators:

• Read the full installation and operating manuals from the vendors. They can sometimes be downloaded from the internet.

• Speak to actual users of the equipment.

• Contact local government regulators.

• The pictures on the right show that cleaning of Plate Pack type separators can be a messy affair!

• Note: The plate pack contains only a 20 l oil drum. This has filled and is now overflowing creating a mess and non- compliance with discharge. Ultraspin supplies a 500 l oil drum as a minimum to avoid these problems.

Flow rate

For most conventional oily water separators, like plate packs, the separation efficiency reduces as the flow increases.

But for the Ultraspin system it is the opposite! Increased flow increases the strength of the centrifugal forces increasing the oil separation force.

Reject Ratio

The ‘reject ratio’ is the ratio of the oily reject stream leaving the Ultraspin separator to the inlet of feed flow rate of fluid to the separator. This is an important parameter in the operation of the separator. Typical reject ratios are from 1 to 20% subject to design requirements.

A minimum reject ratio exists below which the efficiency of the separator can be impaired. This depends on the size of the reject orifice. A high reject ratio does not affect the performance of the separator. However, it leads to excess water in the separated oil reject and can result in unnecessary recirculation of water. Hence, the optimum reject ratio is just above the minimum reject ratio. The reject ratio is usually set by the Ultraspin design engineers and should not require any further adjustment by clients.

Underflow Recycle

A proven method of increasing the power of separation of the Ultraspin separator is to recycle part or all of the treated underflow back to the inlet for further treatment. This is a feature unique to the Ultraspin separators. In this way very small oil droplets that missed being separated in the first pass have a second chance at being recovered in the second pass. This can greatly improve separation efficiency with emulsified oily water mixtures.

This can be illustrated by an example:

• One pass (no recycle): 85% of 20-micron droplets will be removed.
• Two passes (or 50% underflow recycle): 98% of 20-micron droplets will be removed.

Separator Configuration

• There are many methods to configure a system including:
• Batch Treatment Mode
• Continuous Operation
• Other methods including demand activation etc