Fractionating column feed method for improving distillate yield

Abstract

Disclosed is a fractionating column feed method for improving distillate yield, which comprises the following steps: preheating petroleum hydrocarbon raw oil to be fractionated by a heating furnace; spraying the preheated raw oil into a atomization container under the pressure of 100.0-1000.0kPa higher than the pressure of the atomization container and atomizing into small droplets with the particle size of 0.0001-10 millimeters and vaporizing partly; and introducing the small droplets into a fractionating column for distillation separation; leading out the distillate products from the top ofthe fractionating tower and/or the lateral line and the residues from the bottom. In the method provided by the invention, the vaporization process of the raw oil is accelerated through atomization in order to fully vaporize the distillate in an extreme short period of time, minimize the distillate content in the residual oil to the great extent and increase the yield of distillate oil.

Description

technical field [0001] The present invention relates to a method for increasing the yield of distillate in a distillation unit, more particularly, to a method for increasing the yield of distillate in a distillation column where the feed is partially vaporized in the petroleum refining industry. Background technique [0002] Fractionation tower is a unit equipment widely used in petroleum refining industry. For the fractionation of some heavy oil products, such as when fractionating light distillate oil from crude oil, wax oil and other oil products, the temperature of the distillation tower and the bottom of the fractionation column are high, and the heat source of the reboiler has a high temperature, which is not easy to obtain, and the heavy oil The product is prone to thermal cracking at high temperature, so the general fractionation tower does not have a reboiler. Therefore, the heat source of the tower depends almost entirely on the preheated raw material. After the r...

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Problems solved by technology

[0009] Through the expansion of the furnace tube diameter and the large-diameter oil transfer line, the pressure of the oil product in the furnace tube and the oil transfer line can be continuously reduced to promote the vaporization of more raw materials, but there are also restrictions on expanding the furnace tube diameter. The expansion of the furnace tube must be reasonably designed according to the properties of the raw material oil and the characteristics of the heating furnace, and the variety of raw materials makes it very difficult to design the precise furnace tube

The second is that with the increase of the amount of vaporization, the density of the raw material in the tube decreases continuously, especially in the condition of the vacuum furnace, the density of the oil product drops even more, so that the heat transfer coefficient of the medium in the furnace tube is greatly reduced, resulting in the total heat transfer in the furnace. thermal coefficient drop

In order to achieve the same heat transfer intensity, the temperature difference must be increased, that is, the temperature of the furnace and the furnace tube should be increased. As a result, the temperature of the tube wall will be too high locally, the tube wall will be coked, the furnace tube will be damaged, and the heat transfer efficiency will decrease.

[0010] In addition, the insufficient height of the vaporization section of the fractionation tower will lead to excessive mist entrainment, which will affect the product quality of the tower top and side line, and affect the yield of distillate

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