The bottom reflux oil enters the vacuum furnace (Furnace-102) after being exhausted by the pump and pressurized. Then it enters the vacuum tower (Tower-104) through the low-speed transfer line for separation after heating up to 380℃. Vacuum overhead oil gas is led from the vacuum overhead volatilizing line and passes through the first, second and third level vacuum water cooler and evacuator. Then it is cooled down to 50℃. The condensed oil and water flow into the vacuum overhead separate tank (volume-105), and the vacuum overhead oil is pumped out of the equipment, with the vacuum degree remaining about 99.32KPa (745mmHg). Vacuum tower equipped with three padding sections, three layers of the oil sump tank, three combined liquid distributors, and metal mellapale packing on the first two layers and metal intalox saddle in the under layer.
The first vacuum side stream is exhausted from the first layer of the oil sump tank and cooled down to 80℃ after heat exchange, some of which flows out as product and some of which returns to the upper part of the first padding section as vacuum overhead reflux oil after being cooled down to 40℃ by the condenser.
The second vacuum side stream is exhausted from the second layer of the oil sump tank, one line of which is cooled down to 80℃ after heat exchange and flows out as a product, one of which returns to the upper part of the second padding section as vacuum overhead reflux oil and the other of which returns to the upper part of the third padding section as light wash oil with no need to be cooled.
Excess vaporization oil (third vacuum side stream) is exhausted from the third layer of the oil sump tank, some of which returns to the upper part of the third padding section as heavy wash oil, some of which mixes with the second vacuum side stream, enters into the integrated heavy oil line which is cooled down to 80℃ after heat exchange and flows out as product. Before heat exchange, lead a branch to the inlet of the oil pump, which can be used in the equipment wire in case of furnace tube coking when the production reduces or the flow of bottom oil fluctuates.
The vacuum residue is extracted from the bottom of the vacuum tower by the pump after it is cooled to 120 ℃, one of which flows out, one of which mixes with the second and third vacuum side stream into the integrated heavy oil line and flows out.