How to calculate backwash regeneration water for demin plant?

[9415]

Does anyone know how to calculate backwash regeneration water for demin plant? How do I know that how often does the water treatment plant need to be regenerated? What would be criteria? Is there any significant waste water released from or water added in demin plant apart from regeneration?
Thank you in advance

 

[bimr]

The backwash rate selected is subject to the type of resin and the backwash water temperature (check the backwash expansion curves in the manufacturer's literature). Typical is 4-10 gpm/ft2 for 10 minutes.

The regeneration frequentcy depends on the concentration of ions in the water and the amount of resin in the tank.

The significant wastewater loadings derive from the acid and caustic regeneration steps and the initial stages of the rinsing the reagents out of the bed.

 

[jmj5152]

The way you phrase your question implies that you are new to regeneration of resins. It is common for people to refer to the entire regeneration process as "backwash". If you pick up any ion exchange resin specification sheet, it will give you the flow rates, chemical concentrations, and times required for each stage of the regeneration process. The flow rates are different for each stage.

 

[GarySCWSVI]

The criteria for knowing when to regenerate a demineralizer is what is the quality of the feed water, how much demineralized water needed, what will be the resulting water quality you want and when it gets less than that is when you want to regenerate it. You should have a Water Quality Monitor on the system that allows you to see what water quality it is producing. As jmj5152 mentioned "backwash" is just one (the first) part of the cycles of a process called "Regeneration".

Additionally, all of this is affected by the quantity and type of ion exchange resin in the system. Your question is basically too general to give you any more specifics.

Gary Schreiber, CWS VI
The Purolite Co.