Regeneration of the alkali scrubber tower
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How often is it appropriate to replace the absorbent solution in the alkali scrubber tower? What criteria are used to determine when it’s time to replace the absorbent solution? Taking my family’s setup as an example, the alkali scrubber located after the RTO in my home serves both to cool the air and to absorb acidic gases; it requires frequent replenishment of water and alkali. But what is the appropriate standard for replacing the absorption solution? Replacing it too frequently results in a large amount of wastewater, while on the other hand, the filler in the scrubber is prone to forming salts
It is recommended to add an alkali replenishment pump, set the pH value to >12, and operate it automatically
The problem now is determining the most appropriate time to replace the absorbent solution. I’m not sure if anyone has any experience in this regard. Generally, the absorbent solution is replaced when its pH reaches a certain level. The RTO’s alkali scrubber consumes a lot of water, so it needs to be replenished continuously, as does the alkali used. This raises the question of how to replace the absorbent solution
Add a level gauge for automatic water replenishment, and adjust the addition of alkali automatically based on pH. A solvent tank can be set up to manually add caustic soda for preparation.
This post was last edited by Liu Yi84 on 2021-6-19 at 14:10. Create an automatic control system to add alkali and water automatically; it’s possible to calculate the amounts of alkali and water to be used in order to save resources
The problem description is still not detailed enough; whether it’s controlling the pH value or the alkali concentration, it all depends on the manufacturing process. Two points need to be carefully considered: 1. Process requirements, such as which substances need to be removed and what pH level is required for the components in the exhaust gas to meet the specified standards ； 2. Are there any requirements regarding the material of the equipment after alkali washing, with regard to certain components in the exhaust gas? It is through these two points that the requirements for the alkali in the alkali washing cycle can be determined!
The amount of base should be calculated based on the amount of acid absorbed, and then determined using the concentration of salts precipitated. I’m not sure if this is right!
It should be like this, but isn’t it appropriate to discharge it when the salt content is at a certain level? Should it be discharged when saturated, or only after a certain amount of salt has accumulated in the absorption tower?
The poster is asking when it’s time to replace the absorbent solution entirely Under normal circumstances, in an alkali scrubber tower, it is necessary to monitor the pH (or alkalinity) and conductivity. During normal operation, the pH (or alkalinity) is controlled in order to add water and alkali; when the conductivity of the absorption solution rises to a certain level, it needs to be replaced, and this is determined based on empirical values.
In other absorption towers, the quantity used keeps increasing, and when the liquid level rises, part of it or all of it is replaced. This is the first time I’ve encountered a situation where water needs to be added continuously
Water needs to be added due to the issue of gas-liquid entrainment; normal-designed absorption towers generally do not experience this problem, unless the exhaust volume is particularly high or the temperature is high.