Cyclonic distillation tower for waste oil rerefining process

Claim 1

A cyclonic distillation tower for treating waste oil having high boiling point impurities therein, said tower comprising: structure defining an elongated, upright, enclosed chamber presenting a substantially cylindrical upper vapor zone defined at least in part by a substantially cylindrical sidewall and a top wall, and a lower liquid collection zone, said chamber being constructed for maintenance of equal pressure conditions within said zones during operation of said tower; flowing-directing means for supplying said waste oil to said chamber, for imparting a whirling motion to the waste oil as the latter enters the chamber, and for enhancing the vaporization of a major proportion of said waste oil from said high boiling impurities to yield a recoverable product, including a tangentially disposed inlet through said sidewall defining said upper zone and in communication with the latter; nozzle means operatively disposed adjacent said inlet for tangentially spraying said waste oil into said upper zone; substantially tubular baffle structure positioned radially inwardly from and adjacent to said inlet and extending downwardly therefrom which presents an annular confining space between the baffle structure and said defining sidewall of said upper zone for directing said waste oil sprayed into said upper zone, and the major proportion vaporized therefrom along a generally circular whirling path; means for maintaining the temperature conditions within said chamber at a level for maintaining said vaporized major proportion of waste oil in the vapor state in the upper zone; means for creating negative pressure conditions within said upper zone, said flow-directing means, temperature-maintaining means and negative pressure-creating means cooperatively serving to flash vaporize from about 50 to 95% of said waste oil as the waste oil enters said upper zone for ensuring a high degree of separation of said vaporized oil from said high boiling impurities; vortex-breaking structure disposed within said chamber generally between said zone for preventing entrainment of the nonvaporized high boiling impurities into said vaporized major proportion of said waste oil, said vortex-breaking structure also being spaced from said nozzle means a distance for ensuring complete separation between the vaporizable proportion of said waste oil and said high boiling impurities; means in communication with said liquid collection zone for withdrawal of liquids collected therein; and means in communication with said vapor zone for withdrawal of the vaporized proportion of said waste oil, including a tubular outlet conduit generally centrally and axially disposed within said upper zone which extends through said top wall and into said upper zone.