The final step in the oily sludge separation process involves a crucial three-phase separation to oil, water and solids, and there are two primary options available for achieving optimal results, as recommended from the Separation specialist – GN Solids Control.
Option 1: GN Solids Control Two-Phase Decanter Centrifuge + Three-Phase Disc Centrifuge
This option employs a combination of two-phase decanter centrifuge followed by a three-phase disc centrifuge for fine separation. The decanter centrifuge is initially used to separate the bulk solids and liquids, while the disc centrifuge performs the critical three-phase separation, separating oil, water, and solids with high efficiency.
The disc centrifuge offers a significant advantage by achieving cleaner outputs for both oil and water. It is particularly effective in reducing the Base Sediment & Water (BS&W) content in the oil. BS&W is a key parameter in defining the quality of the oil, and the lower the BS&W, the higher the oil quality. With the disc centrifuge, the output oil typically has a BS&W of 2-3%, ensuring higher purity and quality.
The water output from the disc centrifuge ranges from 1000 to 3000 RPM, depending on the specific settings and operational conditions, ensuring that the water is effectively separated from the oil. Additionally, the solids content in the output oil from the disc centrifuge is typically between 1-3%, maintaining the quality and clarity of the oil while efficiently removing contaminants.
Option 2: Three-Phase Decanter Centrifuge
The second option utilizes a single three-phase decanter centrifuge for all three-phase separation. This centrifuge directly separates the oil, water, and solids in one step. It is a simpler, more compact solution, which may be ideal for certain operational setups where space or equipment complexity is a concern.
The three-phase decanter centrifuge is effective in producing the three separate outputs—oil, water, and solids—though the quality of separation may not be as refined as with the combination of a decanter centrifuge and disc centrifuge. This option is suitable for applications where a balance of performance and operational simplicity is desired, but it may not achieve the same level of oil purity as the multi-stage separation process.
Each option offers distinct advantages, and the choice between them depends on factors such as the desired oil quality, operational conditions, and system requirements. Operators can contact GN Solids Control engieers to ask for more suitable solution.