The dehydrated oil along with additive is pumped at a controlled rate to the vaporizer by feed pump. The oil vaporizes during its passage through vaporizer. The heating is accomplished by burning gas oil in the vaporizer, which is generated in the plant. The heating is done by convection alone by re-circulating flue gases over the tubes by flue gas circulation blower in the convection section of the vaporizer.

The vaporized oil along with bitumen, carbon and other non vaporizing matter enters the separator where the vapors disengage from the non vaporized bituminous type residue material which is directly pumped into barrels by bitumen pump to be disposed of for blending with bitumen. The level in the separator is controlled.

The vapors from the separator enter the direct contact heavy base oil condenser, where the vapors partially condense and the temperature of condensation is controlled by refluxing the condensed heavy base oil. The viscosity of the condensed heavy base oil is thus controlled.

The heat of condensation in the heavy base oil condenser is utilized to generate steam in the steam drum by circulating hot water through heavy base oil circulation cooler by hot water circulation pump. The steam generated is used in booster ejector.

Part of the condensed heavy base oil is pumped through a level controller to the heavy base oil cooler as recovered heavy base oil. Cooling water is used in heavy base oil cooler.

The non-condensable along with uncondensed oil vapors enter light base oil condenser. The temperature and level control on this condenser is similar to that of heavy base oil condenser, except that the condensing temperature is set at a lower value to allow the condensation of light base oil. The viscosity of the light base oil is thus controlled. The heat of condensation of light base oil is utilized to preheat feed through light base oil circulation cooler.

Part of the condensed light base oil is pumped through a level controller to the light base oil cooler as recovered light base oil. Cooling water is used in light base oil cooler. The non-condensable along with remaining oil vapors enter gas oil condenser. The temperature and level control on this condenser is similar to that of light base oil condenser except that the condensing temperature is set at a lower value to allow the condensation of maximum gas oil and allow only non-condensable to go to vacuum system.

Part of the condensed gas oil is pumped through a level controller on the gas oil circulation cooler as recovered gas oil. Cooling water is used in gas oil circulation cooler.

The entire operation is carried out under vacuum which is maintained by a combination of booster ejector, inter cooler and a two stage vacuum pump in the system. Steam required for booster ejector, is produced in the plant itself.