Ion-exchange plants
In order to meet the requirements for their process waters, many water users apply ion-exchange technologies for water demineralisation. For these systems the regeneration of ion-exchangers is critical and a periodically repetitive part of the operation of the entire plant. In this context, the key indicators in view of the utilization are the consumption of chemicals for regeneration, the consumption of water for own needs, the amount of post-regeneration waste water, especially if they are related to expenses for waste management, and regeneration time, which is usually equivalent to the down-time of the plant or demineralisation line. All these aspects relate to both conventional cocurrent and older countercurrent regeneration plants. At present, there is a new technology available which uses the regenerating chemicals more efficiently, significantly reducing the amount of waste water and reducing the negative post-production impacts.
Upcore system – the countercurrent ion exchanger regeneration plant with a top to bottom water flow. A leading, more efficient and cost-effective ion exchange demineralisation plant. UPCORE system is a countercurrent ion exchanger regeneration plant with a bottom to top flow, the way for which was paved by The Dow Chemical Company.
Advantages of UPCORE system:
- simple structure,
- easy to operate and automate,
- inexpensive,
- ideal for upgrading,
- easy creation of layered bed systems,
- optimum use of ion-exchange unit’s volume,
- insensitive to changes in flow rate,
- self-cleaning.
The ion-exchange technology is used for water softening and demineralisation to obtain a highlevel of water purity. The ion-exchange system enables the complete removal of cations and anions from water.
UPCORE and layered bed:
Layered beds are an efficient and cost-effective alternative to separate exchange units used for strong and weak ion exchangers in a demineralisation line.
When using layered beds, less ion-exchange columns are required and the chemical efficiency of the regeneration is increased.
The system with a layered bed is a highly cost-efficient way to obtain benefits in relation to the high exchange capacity of ion exchangers and the removal of organic compounds by the weakly basic anion exchanger to secure and optimise the exchange capacity and the lifetime of the strongly basic anion exchanger. This enhances the system due to the ability to remove silica.
Advantages of layered bed system:
- fewerexchange columns required,
- high total chemical efficiency (85%-95%),
- high exchange capacity of weakly basic anion exchanger,
- optimum silica removal by strongly basic anion exchanger,
- extended life of ion exchangers as the weakly basic anion exchanger protects the strongly basic one against irreversible contamination by organic substances,
- ability to adjust the ratio between the volume of ion exchangers and the variable quality of feed water,
- easy modification of existing exchange columns for UPCORE layered bed system.
All the benefits from using countercurrent technology in terms of water quality, economics and process efficiency, without the issues pertinent to older countercurrent technologies.
Reduction of system’s sensitivity to feed water flow rate fluctuations with no risk that the exhausted ion exchanger will contaminate the highly regenerated secondary treatment zone at the outlet of the ion-exchange column.
Fewer problems with the occurrence of undersize and other small particles because, in contrast to systems with a working flow from bottom to top, the ion-exchange bed is self-cleaning and fine particles collect on the end opposite to the outlet of the exchange column.
Greater utilisation of the tank to obtain the maximum exchange capacity, because space requirements are far lower than for systems with beds maintained with water and air.
The option with layered beds for improving the demineralisation efficiency increases the lifetime of ion exchangers and enables top quality water to be obtained.