Patent ID: 8784648

Claim:
A method for producing vacuum in a vacuum oil-stock distillation column, said method comprising: pumping a gas-vapor medium out of the vacuum column by a gas-gas ejector by feeding a high-pressure gas thereto with generation of a gas-vapor mixture at an outlet of the gas-gas ejector with a pressure higher than that of the gas-vapor medium at an inlet of the gas-gas ejector; feeding the gas-vapor mixture into a condenser followed by cooling thereof and generating a gas mixture and a vapor phase condensate; feeding the gas mixture and the high-pressure gas into a second gas-gas ejector with generation a gas-vapor mixture at an outlet thereof with a pressure higher than that of the gas mixture at an inlet of the second gas-gas ejector; feeding the gas-vapor mixture from the second gas-gas ejector into a second condenser followed by cooling thereof and generating a gas mixture and a vapor phase condensate at an outlet of the second condenser; and discharging the gas mixture out of the second condenser for a designated purpose, said method further comprising directing the vapor phase condensate generated in the condenser and in the second condenser into a separator where the vapor phase condensate is separated into a water-containing condensate and a hydrocarbon-containing condensate; discharging the hydrocarbon-containing condensate out of the separator for a designated purpose while feeding said water-containing condensate by a pump into a steam generator where heat from a hot distillate discharged out of the vacuum oil-stock distillation column or an oil refining column is supplied to the water-containing condensate and obtaining a steam from said water-containing condensate, and feeding said steam as a high-pressure gas into the gas-gas ejector and the second gas-gas ejector from the steam generator.