Hawk Measurement Systems recently provided a 3 crystal sonar transducer with automatic scum cleaning impact plate for a customer that had multiple coal types that they processed through the coal prep plant.
Some coal types had different settling characteristics and this affected the tailings thickener efficiency and the "clarometer" instrument that tested settling rates in the incoming feedwell. The instrument failed from time to time, meaning that the floccing rate changed and the suspended solids increased, decreasing the quality of the return water back to the prep plant.
Hawk Measurement Solutions provided a high powered 3 crystal sonar transducer with automatic scum cleaning impact plate as a solution for this problem.
The two outputs of the Sonar transducer system provided:
- BED Level (Heavy density compacted interface)
- Hindered/fluffy layer (low density interface)
The hindered/fluffy layer was used to monitor the deviation distance between it and the heavier compact bed. As the deviation moved greater than a set distance flocculent dosing increased. As the deviation decreased flocculent dosing decreased.
The high powered 3 crystal array sonar transducer is able to penetrate suspended solids, even under poor settling conditions. The hindered/fluffy layer output could also be used, in the floc dosing control loop to automate this function if the "clarometer" failed.
Hawk manufacturers a large range of sonar transducers to provide optimised performance for all bed level thickener applications, for example concentrate thickeners.