Anti-salt formation method, anti-salt formation system and application of refinery unit

Abstract

The invention provides an oil refining device salt deposition prevention method and a salt deposition prevention system and application and relates to the technical field of salt deposition prevention. According to the oil refining device salt deposition prevention method, a salt washing process is implemented outside an oil refining device, that is, a corrosive medium is moved outside the oil refining device before ammonium salt is crystallized, then influence of ammonium salt to main body equipment is eliminated to the maximum extent, the operation period and the service life of the device are prolonged, and the defects in the prior art that equipment is internally corroded and failed as generated ammonium salt is directly washed and dissolved with water fed into a tower, and stable operation of a later device is affected if an ammonium salt solution is sucked out from a side line, are alleviated. The invention further provides an oil refining device salt deposition prevention system which comprises a gas-phase sucking pipeline, a gas-liquid mixer, a hydrocyclone, a separation tank and a backflow main tube, wherein a corrosive medium is moved outside an oil refining device by using a gas-phase sucking pipeline and is sequentially separated into a gas phase, an oil phase and a salt-containing solution through the gas-liquid mixer, the hydrocyclone and the separation tank; the gas phase and the oil phase are fed back into the oil refining device; and the salt-containing solution is discharged out.

Description

technical field [0001] The invention relates to the technical field of anti-salt formation, in particular to a method for anti-salt formation of an oil refinery, an anti-salt formation system and its application. Background technique [0002] According to incomplete statistics, since 2005, my country's petrochemical industry (such as oil refining units) has had an average of more than 10 unplanned shutdowns per year due to ammonium salt crystallization and corrosion leakage caused by crystallization, often occurring in atmospheric and vacuum towers, catalytic Parts such as the top of the fractionation tower and the coking fractionation tower seriously affect the safety, stability, and long-term operation of the device, and have a strong negative effect on the economic benefits of the refinery. The existence of this problem makes the internal mass transfer and heat transfer effect of the equipment decrease, and then it is forced to shut down due to temperature and pressure out...

AI Technical Summary

Problems solved by technology

During the washing process, the ammonium salt dissolves in water to form a highly acidic aqueous solution to corrode the environment, which will cause serious corrosion to the equipment over time.

The undissolved ammonium salt washed away is easy to deposit in the low flow rate area, forming an occluded environment and under-deposit corrosion

In addition, increasing the amount of water injection to alleviate the deposition of ammonium salts will easily cause erosion and corrosion due to the increase of water injection flow rate, resulting in failure

[0004] In order to solve such problems, American API Association, NACE Technical Committee, UOP Association and other institutions and organizations have successively conducted a large number of investigations on the corrosion failure of petrochemical systems. According to the analysis, the equipment structure is unreasonable and the process anti-corrosion method is unscientific. Main cause of failure

At present, the countermeasures adopted by my country's refineries mainly focus on directly injecting water into the tower to wash and dissolve the generated ammonium salt. This method not only cannot prevent the interior of the equipment from being affected by salt formation and corrosion, but also has the side line to draw out the ammonium salt solution. Potential hazards affecting the smooth operation of subsequent devices

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