Novel water hardness monitoring
For the production of soft water, ion exchange units with sodium chloride regeneration have been increasingly used for more than 50 years. The course and dynamics of the softening process depend on the ion exchange resins used, the proper regeneration processes, the removal quantities and their dynamics.
These processes do not run constantly in practice, which is why resin capacities are not exhausted in all water softening systems for reasons of variability and the lack of process monitoring. For this reason, the softening plants are traditionally regenerated in quantity or time. Investigations on this revealed capacity reserves of 20% to 50% of the resin capacity used.
It would be desirable to constantly monitor the softening process. The aim is to detect the desired degree of exhaustion and to perform the regeneration control of the water softening system dependent on the hardness. However, this is not possible with today's largely traditional and known photometric measurement techniques.
Process-safe continuous soft water monitoring
By means of a novel soft water monitoring process, which was developed with the product line 'Softcontrol' of the OFS GmbH, a measuring and control device with potentiometric measuring procedure for the permanent monitoring of the soft water is presented. This not only monitors the residual hardness and the measurement functionality very sensitively in cyclic circumstances, but also has intelligent self-monitoring.
Previous problems and obstacles of conventional measuring techniques are solved and a high reliability and economically continuous measuring functionality is ensured over long periods of time.
The process principle is based on a calcium-magnesium-selective electrode, which constantly determines the difference in water hardness between hard and soft water and evaluates to a predetermined limit.
The applied differential method offers the possibility to exclude sensor drift and to monitor the sensor quality. Thus, the soft water hardness is monitored, so that a high process and control security is given. According to these possibilities not only limit value monitoring in soft water, but also optimal conditions for a quality controlled regeneration of softening plants are proven. Thus, a premature regeneration release is prevented by hardness and the soft water capacity is optimally utilized.
Effective capacity utilization
For the first time, this principle, with sensor life independent of the measuring cycles and lacking indicator means, enables continuous monitoring of water softening systems under economically effective conditions.
Thus, according to different practical conditions, 20% to 50% fewer regeneration cycles could be achieved when switching from batch to quality-controlled operation of the water softener. This reduced regeneration costs, kept the amount of soft water constant and the quality of the water high.
The new measurement process provides an economical, process-safe alternative to monitoring the softening process. This ensures the full utilization of the capacity of the softening plants, so that resources are saved. So rinse and salt water are significantly reduced and increases the amount of soft water. The device family leads to a high level of process reliability and, at the same time, ecological operation.