| 摘要 |
<p>A wax-containing mixture which has been cooled to form wax crystals is separated in a primary hydrocyclonic zone into a primary underflow stream comprising at least a portion of the wax crystals and a primary overflow stream, the primary underflow stream is treated in at least one secondary hydrocyclonic zone, solvent being introduced into the (or the last) secondary hydrocyclonic zone, to yield a wax product, and/or the primary overflow stream is treated in at least one tertiary hydrocyclonic zone, to yield an oil or a lighter wax product. Mixtures which may be thus treated include the waxy distillate or waxy residual oils, oily paraffin or oily microcrytalline waxes obtained from distillate and residual oils respectively, or a mixture of paraffin and microcrystalline waxes. Cooled waxy oil 5 is separated <PICT:1073809/C4-C5/1> in primary hydrocyclone 7 into a predominantly liquid overflow 9 and wax-containing underflow 11. The halves of the Figure above and below 7 illustrate the subsequent de-waxing of the oil and de-oiling of the wax respectively. De-oiling is carried out in three secondary hydrocyclones 15, 27, 31 and a separator 41 from which crude wax is obtained. De-waxing takes place in three tertiary hydrocyclones 55, 61, 65 and a separator 75 from which oil is withdrawn. Arrowed lines indicate recycling &c. The solvent is propane. Other solvents are specified.</p> |
