| 摘要 |
In solvent de-waxing of lube oil, a stream (3) of chilled waxy oil and solvent is introduced into a centrifugal separation device (2) which separates a quantity of wax from the waxy oil and solvent. The dewaxed oil (DWO) and solvent leaving the centrifuge (2) contains a small proportion of wax fines. By introducing free excess charge which is net unipolar into the stream (3), for example by injecting the charge into a stream (9) of cold solvent introduced into stream (3), enhanced deposit of wax on the centrifuge bowl is achieved, thereby substantially removing the wax fines from the dewaxed oil (DWO) and solvent. Alternatively, a bead separator (22), itself employing charge injection with a charge injection (26) for enhanced wax separation, is used for substantially removing the wax fines in the dewaxed oil and solvent from the centrifugal separation device (2). Preferably, both introduction of free excess charge into the stream (3) admitted to the centrifugal separation device (2) and a bead separator (22) are employed, which can lead to higher throughput in the equipment with minimal wax content of the dewaxed oil and solvent leaving the bead separator.
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