Blockage in the packed tower
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I have a question for the experts here: Our company uses packed towers in the production process, and product A tends to crystallize inside Tower A. This crystallization causes blockages at the top of the tower – probably at the distributor area – which hinders backflow (in an internal reflow distillation column, not an external one). As a result, there is an excess of product A in the bottom of the tower, which affects the distillation process in Tower B. Additionally, the A product obtained from the top of Tower A is of poor quality, as it contains other components that were not separated properly. Is there any effective way to prevent substance A from crystallizing inside the tower? This substance belongs to the category of organic amine salts. Thank you!
Add two solvents that can dissolve organic amine salts; adjust process parameters such as temperature without affecting production.
Adding a heat exchanger appropriately increases the temperature of the mixture, such as in the tower.
The choice of tower type you’ve made is fundamentally wrong; a packing tower cannot be used for media that tend to form crystals. It is recommended to eliminate the packing and other internal components of the tower, and instead use the existing shell to design a tray structure, in order to resolve the problem at its root.
For the purification of materials that crystallize easily, a distillation tower must be used at a temperature above the crystallization point; otherwise, normal operation is not possible, and a crystallization process must be employed instead.
We have encountered similar situations as well; we regularly disassemble it for maintenance. There is a backup tower
Medium crystallization occurs under certain conditions; check your process parameters and consult relevant materials to see if they match the design parameters
I wonder what the crystallization temperature of the material harvested by the original poster is? The top temperature of the tower should be maintained above the crystallization point of the material. It is possible to increase the top temperature of the tower or reduce the reflux flow!
Half of the medium is crystallized: 1. The medium is operated at conditions close to its crystallization temperature； 2. The medium is operated under conditions close to its crystallization pressure.
Can substances that crystallize easily be recrystallized using a solvent? If a packed tower is to be used, it is recommended to install a heat exchanger at the top of the tower to heat the outlet stream and prevent crystallization
It is recommended that you consider distillation under negative pressure; if you are already operating under negative pressure, then think about the level of that pressure and add a heat exchanger to appropriately raise the temperature of the mixture in the tower
Thank you to all the sea friends for their answers. Previously, this substance was produced using a floating valve tower, but the production capacity was low. The setup now is another one; all of them have a larger production capacity than float valve towers. The tower pressure is 0.42 MPa, and the temperature of the product at the top of the tower is around 66 degrees; temperatures above 67 degrees are considered unacceptable. 66 degrees is the temperature at the first point at the top of the tower; the temperature at the second point is usually around 67 as well. There is a significant difference between these temperatures, which can reach up to 90 degrees. As long as the temperature remains within this range, the product is considered qualified. If the temperature exceeds this level, other components in the tower bottom are extracted, and the product becomes unqualified. We washed it once, but we had to stop and fill the tank with water and heat it with steam in order to remove the dirt. Crystallization occurs not only inside the tower but also in the production pipes, and this phenomenon is particularly severe during intermittent production. Dear sea friends, please analyze again and suggest any good ways to solve this issue. Thank you! Our tower has internal flow back.