A device for preventing salt accumulation in an oil fractionation tower

Abstract

The invention relates to the technical field of petrochemical engineering, and discloses a device for preventing salt deposition of an oil fractionating tower. The device comprises a fractionating tower, a top circulating oil pump, a top circulating oil heat exchange device, and a top circulating oil purification loop, wherein the top circulating oil heat exchange device is connected with the fractionating tower and the top circulating oil pump through pipelines, so that a top circulating oil loop is formed; the top circulating oil purification loop is connected in parallel between an oil output end of the top circulating oil heat exchange device and the fractionating tower, and comprises an oil-water mixing device and an oil-water separation device which is connected with the oil-water mixing device through a pipeline; an oil input end of the oil-water mixing device is connected with the top circulating oil heat exchange device through a pipeline; an oil output end of the oil-water separation device is connected with the fractionating tower through a pipeline. The device provided by the invention has the advantages that ammonium salt, a major substance for salt deposition of the fractionating tower, can be effectively removed, so that ammonium salt accumulation in the fractionating tower is eliminated, deposition of ammonium salt crystals on the equipment is prevented, salt deposition of the fractionating tower is suppressed, and long-cycle safe and steady running of the fractionating tower is guaranteed.

Description

technical field [0001] The invention relates to the field of petrochemical technology, in particular to a device for preventing salt formation in an oil fractionation tower. Background technique [0002] Due to various factors such as the deterioration of oil products, the increase in the salt content of crude oil in the process of oilfield exploitation, and the decrease in the efficiency of the electric desalination of the atmospheric and vacuum equipment, the upper top circulation section of the main fractionation tower of the catalytic cracking unit and the coking unit often has serious failures. Due to the phenomenon of salt accumulation, the fractionation tower of some devices needs to be washed once every two months on average, which has a great impact on production. [0003] The raw material oil for secondary processing units such as catalytic cracking and coking of heavy oil comes from the wax oil or residual oil of atmospheric and vacuum units. Although the crude oi...

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Problems solved by technology

[0005] 1. The washing process must reduce the processing capacity of the device or shut down, which will affect the operating load of the air compressor

The pressure fluctuation of the fractionation tower is large, which may easily cause the air compressor to fly

If the water washing process is not properly controlled, the water entering the middle section of the circulation will cause the middle section pump to be evacuated, causing the tower to flush, posing a safety hazard

[0006] 2. After each treatment, the quality of diesel oil is temporarily controlled, and the operation tends to be stable. However, with the prolongation of the start-up time, the pressure drop of the fractionation tower will continue to increase, resulting in serious "overlapping" of the distillation ranges of gasoline and diesel oil, and the product quality hard to control

[0007] 3. The fractionation tower is treated only after salt formation occurs, which cannot guarantee the long-term safe and stable operation of the device

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