How to remove salts from the coking top cycle reflux system
Thread Content
Salts in the coking top circulation system
The washing process of the catalytic cracking fractionator can be used as a reference for carrying out the operations! Specific keywords related to this can be found in the forum; there are also detailed implementation processes and plans available!
Note: Use demineralized or deoxygenated water for washing. Normally, control the temperature of the top circulation draw and the return to the tower so that it is not too low, in order to prevent clogging of the tower trays
Generally, washing with water is sufficient, using deoxygenated water for this purpose, but care should be taken.
It is necessary to control the salt content of the feed so that it does not exceed the specified limits. If it is difficult to control the quality of the raw material and salt accumulation occurs in the fractionation tower, online washing is the only option. The washing procedure is the same as that used for catalytic fractionation towers
Design plan for adding an online desalination system to the top circulation of the coking fractionation tower
Rinse with deoxygenated water; use the minimum processing volume. Inject deoxygenated water from the top circulation system, gradually increase the water volume, and control the temperature carefully to prevent tower flooding as well as fluctuations caused by the entry of deoxygenated water below the middle section. Cut off the water supply at the inlet of the top circulation pump until the water becomes clearer
Properly carry out the electrodesalination process for raw material pretreatment, increase the temperature at the top of the distillation tower appropriately, and perform water washing – water washing is the key step. Keep the load between 60-70%; add deionized water or deoxygenated water after the top circulation control valve. Fresh water should not be used. This is something everyone knows, so no further details are needed. . . . . . . . . One issue to note is that salt deposition in the top circulation system not only damages the pipelines (requiring regular thickness measurements), but it also causes damage to the mechanical seals of the top circulation pumps. Special attention is required.
1. Continuous ammonia injection on a regular basis. 2. When top-loop salt formation occurs, use crude gasoline for water washing of the tower.
Your coking units inject ammonia, while we here only inject corrosion inhibitors