FIELD: chemistry.
SUBSTANCE: method of hydrocarbon flow high-vacuum distillation comprises: i) passing of the hydrocarbon flow, which represents a flow of residue leaving the crude oil distillation unit (CDU) having an initial boiling point of at least 230°C and lower than 500°C, to a pre single flash drum (10) where conditions of hydrocarbon flow separation into pre single flash liquid and pre single flash vapour are maintained. The pressure ranges from 0.1 atm (abs.) To 0.8 atm (abs.) and the temperature ranges from 340°C to 360°C; ii) passing of pre single flash liquid to a vacuum furnace (20), where conditions for heating and partial evaporation of the pre single flash liquid are maintained, iii) passing of the flow heated in a furnace to a zone (50) located in the lower part of the vacuum distillation column (30), where the fractionation conditions are maintained, and iv) passing of the pre single flash vapour to the vacuum distillation column (30) in the secondary zone (40) located in the lower part of the vacuum distillation column, wherein the secondary zone (40) for injecting the pre single flash vapour is located lower at the bottom of the steam-purge zone, shich is located lower than the zone (50) for injecting the flow escaping from the furnace, so that the residue of the flow escaping from the furnace makes contact with the pre single flash vapour in the steam-purge zone under the conditions of the residue steaming. The pre single flash vapour is used for steaming the flow ecaping from the furnace in the vacuum column. The use of aqueous vapour as a steaming medium is completely excluded. The invention also relates to a high vacuum unit (HVU) arranged for performing the method of vacuum distillation.
EFFECT: energy saving due to exclusion of aqueous vapour consumption, reduced raw material supply to the furnace and increased output of paraffinic distillate.
5 cl, 2 dwg
