Salt & Water Saving Counter Current Water Softeners
Capacity: 1200 m³/day
In some areas of the world including the UK there has been concern about excessive use of salt and water during the regeneration phase of base exchange softeners.
Traditional softening involves the supply of a substantial overdose of brine rich water to remove calcium and magnesium ions from the resin bed.
This water is discharged to drain and is often unregulated in its volume and quality. As a result excessive water and salt use is common with a resulting increase in cost.
The process by which this occurs in a normal softening plant is called co-current regeneration.
Higher efficiencies can be acheived by reversing the regeneration direction and controlling more accurately the ratio of brine and water in relationship to the softening resin.
This is called counter current regeneration.
For companies who have a genuine interest in meeting stricter environmental requirements and want to save money (the payback in water savings can be in under a year).
A large dairy has recently installed such a plant to comply with their need to minimise waste discharge off site and the payback in consumables and water is less than 18 months.
Units normally are provided with a central control panel complete with HMI touch screen controller with external communications package for MODBUS/PROFIBUS RTU communication, operating the control valves.
The softener vessels can be regenerated on the basis of volume passed as well as time elapsed. The time of the actual regeneration and also the length of the different regeneration steps can be programmed.
The display of the PLC shows:
Digital flow meters feeding the control unit with pulses for the volume controlled regeneration and totalising the water consumption.
A conductivity cell in brine drain outlet to ensure that water usage in regeneration is kept to an absolute minimum.