Water for industry
Decarbonisation & softening
In weakly acidic cation exchangers the raw water is decarbonised. In this process carbonic acids form compounds with the available carbonic acids of the raw water. The carbonic acids are removed in the CO2 deaerator fitted downstream.
The exchange of the remaining carbonates is made in the following sodium exchanger.
The finished water is softened and only contains a low volume of carbonic acids and has a lower salt content due to the exchanged cations which were bound to the hydrogen carbonates.
If a CO2 deaerator is not used, the sodium exchanger must have a correspondingly larger design. The capacity of the sodium exchanger will be utilised to a certain extent by the carbonic acids.
The removal of the carbonic acids resulting from the splitting of the hydrogen carbonates in the cation exchanger can be made in a strongly alkaline exchanger. The large amount of chemicals required to do this mean that the removal of CO2 through deaeration of the decarbonised water is more economic.
The water flows into the upper part of the deaerator and flows through a nozzle floor which has a reverse airflow.
The number of the nozzles is matched to the CO2 content and the water which must be deaerated.
The air intake is made through a blower unit with a filter upstream to ensure that the air blown in is free of dust.
The air leaving the upper part of the deaerator is directed into the atmosphere.