Oil Removal Systems

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The API separator, or American Petroleum Institute separator, is a gravity separation device designed using Stokes Law to determine the rise velocity of oil droplets based on their density and size. The separator's design relies on the specific gravity difference between the oil and wastewater, as this difference is smaller compared to the specific gravity difference between suspended solids and water.

According to this design criterion, most suspended solids settle to the bottom of the separator, forming a sediment layer. Meanwhile, the oil rises to the top of the separator, creating a distinct layer above the wastewater, which occupies the middle layer between the oil and the solids at the bottom. This gravity-based separation process allows for the effective removal of oil and suspended solids from wastewater, facilitating the treatment and purification of the water.

Dissolved Air Flotation (DAF) is a physio-chemical treatment method in which air is closely contacted with an aqueous stream under high pressure, causing the air to dissolve in the liquid. The pressure on the liquid is subsequently reduced through a back pressure valve, leading to the release of micron-sized bubbles. These bubbles efficiently capture suspended solids and oil present in the polluted stream, transporting them to the surface of the air-flotation unit. This process aids in the separation and removal of contaminants from the water, contributing to the overall treatment and purification of the liquid.

API and CPI (Corrugated Plate Interceptor) separators are commonly utilized for the separation of free oil from produced or effluent water, as well as for the removal of suspended solids in oily water treatment systems (OWS). These systems rely on the fundamental principle of gravity separation, taking advantage of the difference in density between the phases involved, whether it's liquid-liquid or solid-liquid.

The phenomenon of gravity separation dictates that the phase with higher density will settle, while the one with lower density will float to the surface of the fluid. In OWS, the effectiveness of this technique depends on various factors, including the density difference between phases, oil viscosity, properties of the medium, temperature, turbulence, and the nature of impurities present. By leveraging these factors, API and CPI separators facilitate the separation and removal of oil and suspended solids from water, contributing to the purification of the liquid.

Induced Gas Flotation (IGF) is a water treatment process designed to clarify wastewaters or other waters by removing suspended matter, such as oil or solids. This removal is accomplished by introducing gas bubbles into the water or wastewater within a flotation tank or basin. The small bubbles adhere to the suspended matter, causing it to float to the surface of the water. Once at the surface, the suspended matter can be efficiently removed using a skimming device.

IGF finds extensive application in the treatment of industrial wastewater effluents from various facilities, including oil refineries, petrochemical and chemical plants, and natural gas processing plants. This process is particularly effective in separating and removing suspended particles, contributing to the purification of water in industrial settings.