The oily water enters the corrugated plate interceptor via a specially designed slotted cross pipe that distributes the flow over the width of the separator basin. Due to the sudden decrease of flow velocity, a certain number of solids that may be contained in the liquid will settle in the inlet compartment. Depending on the solid’s concentration, a sludge suction device may be included in the design for intermittent removal of accumulated solids.

The oily water continues its way towards the plate packs wall and enters the plate pack from the top on a counter-flow direction. In the laminar flow in each channel (i.e., the distance between two subsequent plates), the minute oil droplets rise by their density is lower than that of the carrier medium and attach themselves to the underside of the upper plate.

The build-up oily layer that is thus constantly being formed at the underside of each plate creeps slowly upwards. The oil film is assisted in its upward movement by the counter-current laminar flow.

At the top of each plate the oil film is concentrated (coalesced) by the plates and leaves the plate at the ‘highest point’ as a thick stream or rising chain of large globules.

The treated water flows through the overflow baffle between the plates towards the outlet; thus, there is no interference between the separated oil and the clean water. The separated oil collects as a layer on top of the liquid surface and can be removed intermittently via the adjustable oil skimmer.

Compact Flotation Systems are used to remove oil and solids from produced water to ensure that it is safe for disposal and re-use. Based on design flow rate and footprint available, Peerless can offer Vertical Compact Flotation Units as secondary treatment systems.

Technology Description

The Peerless Compact Flotation Unit (CFU) is the latest generation compact flotation unit available on the market. The philosophy of compact flotation is the combination of multiple separation technologies including cyclonic and flotation principles. Peerless Compact Flotation Units are available as a single or two stage system, combined or separate oil/gas outlets, the CFU is adaptable to the wide variety of oil industry process conditions and applications.

Advanced Oil-Water Separator “CompacSep” is a next generation Oily Water Separation product which offers technological advantage of Corrugated Plate Interceptor and Flotation technology combined in single vessel or tank. This is used to remove oil and solids from produced water to ensure that it is safe for disposal and re-use.

Process Description

1. Corrugated Plate Interceptor Section

Oily water enters the unit from the top of the vessel through an inlet device. The coalescence section is provided with plate packs which ensure effective separation of all three phases from each other. The plate pack offered by Peerless is the counter- current plate pack technology which removes bulk oil from water in a much smaller footprint compared to other technologies.

An additional feature is that the plate packs will suppress any re-circulation and the motion of waves. In the counter-current design, the small oil droplets rise by virtue of the fact that their density is lower than that of the carrier medium and attach themselves to the underside of the upper plate. The oil film that is thus constantly being formed at the underside of each plate creeps slowly upwards along the plates. The oil film is assisted in its upward movement by the concurrent laminar flow.

At the top of the plates, the oil film is coalesced into a thick stream of oil that quickly rises to the upper part of the tank. The oil then forms a layer, which can be removed by the oil skimmer to an integral oil holding sump.

The water flows through an underflow weir to the treated water section and flows down to the flotation section. The light oil floats to top of the liquid layer and flows to bucket type skimmer provided on underflow weir. The recovered oil will flow to recovered oil chamber of IGF Section.

2. Dissolved Gas Flotation Section

Water enters the unit through flotation section and flows down the length of the vessel through four flotation cells. Each flotation cell is separated from the next by an underflow baffle which is designed to maintain uniform flow through the flotation cell. The recycle stream is taken from treated water section of the flotation unit using microbubble-generating pumps and pumped back to through the whitewater (gas-containing water) distributors. Each flotation cell contains a set of manifold responsible to uniformly distribute the microbubbles.

The entrained gas bubbles have the effect of sticking to the oil droplets and bringing them to the liquid surface where they form an unstable foam/scum layer. The foam and oily water scum are removed using an overflow weir into an oily water collection compartment.

Water leaving the final flotation cell passes around the underflow/overflow weir to the Treated Water Section.

Because the flotation gas is recycled, no additional gas is required. A small gas bleed is often included to refresh the gas in the flotation unit during times of low flow.

Our absorption media is designed for the removal of total hydrocarbons from water, including amongst many, Phenols, PAH and BTEX.

The media is a non-swelling organoclay granular media that removes hydrocarbons from water by means of chemisorption.

Absorption Media Filters are typically used downstream of a hydrocyclones, flotation unit, media filtration as a final stage polishing filter to ensure guaranteed oil in water outlet conditions are met. This can be for an upset condition where performance can deteriorate in upstream process equipment.

The media is supplied in a cartridge form for easy removal and replacement but can also be supplied in bulk beds for upflow and downflow operation.

The vessels can be linked up to oil in water analysers on a bypass line to only come into service when poor outlet quality of upstream processes are detected.

The media works by chemically absorbing hydrocarbons, and this is a bonding process, therefore no release can occur.