Salt deposition problem in atmospheric pressure columns?

It shouldn’t happen; this process generally involves online cleaning. Salt deposits usually form in the upper layers of the tower, and since salt dissolves in water, fresh water can be introduced via the top reflux stream. Once the fresh water enters the tower, the salt dissolves in it, and it is then extracted through one of the side outlets and sent to the reject stream. Therefore, the brine from normal washing generally does not reach the Changsan line, nor does it accumulate there. However, attention must be paid to the method of water washing and its control. When water is injected at the top of the tower, it is essential to keep the temperature at the top below 100 degrees to prevent water from vaporizing. Additionally, the temperature at the outlet where the water is discharged must be strictly controlled between 103 and 105 degrees; if the temperature is too high, the water will vaporize and it will not be possible to remove the salts. If the temperature is too low, the water will flow down to the trays just below the discharge point, and it is possible for it to reach the third stage of the column, resulting in salt deposits forming there as well.

As the quality of oil deteriorates, the salt formation in atmospheric distillation columns, which used to be rare, is gradually emerging. Salt deposition on the trays mainly reduces their porosity, thereby deteriorating the mass and heat transfer efficiency. The operational issues mainly manifest in the following aspects: 1. The top pressure and the temperature at which the side streams are extracted are not well controlled, showing regular fluctuations ； 2. The side-line products have increased in weight ； 3. Due to the increased pressure drop inside the salt formation tower, the difference between the pressure in the vaporization section and the pressure at the top of the tower has become larger than before.

Salt generally dissolves in water, vaporizes along with the water to the top of the tower, and is then separated out through distillation

Does the atmospheric tower in a vacuum distillation unit form salt deposits? What is the mechanism behind the formation of these salt deposits? Has anyone detected salts in the wastewater from washing processes? We have had this unit in operation for one and a half years, and the atmospheric tower has been washed three times – it’s costly and time-consuming. Where does all that ammonium salt come from? What is the purpose of the electrodesalination process in your unit? The deterioration of crude oil is due to its complex composition, which can lead to operational fluctuations; therefore, relatively high levels of operational expertise are required to deal with this issue. It would be unwise to equate the deterioration of crude oil with salt deposit formation in the atmospheric tower. It’s better to mix low-quality crude oil with high-quality crude oil in appropriate proportions for processing