Because of the nature of the environment, it was more efficient instrumenting the coupling and assembling the torque measuring equipment at Datum Electronics, converting the coupling into a custom torque transducer.
The Datum Torque Measurement System was installed onto the shaft along with an inductive power coupling. A stator unit was engineered to fit the envelope around the coupling, which provides power for the shaft unit and acts as a receiver for the torque signal. This design is completely non-contact. Torque and Shaft speed signals are transmitted from the stator, as RS485 data to the control room. The data is displayed and recorded in the control room as either torque or power.
Datum utilised a spare coupling spacer to replace the existing one in line as an exact fit replacement. The Torque monitoring solution provided highly accurate data relating the consistency and performance of the concrete mix.
Data supplied from the shaft provided raw data, indicating how the mix was performing, as it was being mixed. The data transmitted from the shaft showed the sharp rise in torque, as the load is added to the mixer and the drop off in torque (viscosity) as the mix becomes more consistent. Operating staff are able to “tune” the mix by the addition of fluid to attain the desired consistency in the shortest time. The repeatability of the data from the torque signal has allowed a reduction in
the time required to achieve this.
Analysis of the logged data shows that not only does the data revealed the change of viscosity, but it also shows the consistency of the mix in term of the lumps within it. Once the mixture was at the right consistency as indicated by the data, it could be dropped and the next load made ready. The display of data for the operator wasoptimised to show the exact performance of the mixing process.
Due to the fluctuations in the mixing process, the data was smoothed in a software programme, giving an averaged torque level, allowing the user to know the exact performance of the mix.
Following successful proving trials on the first mixer, a second system was ordered and installed. Once the first unit was installed, a second Torque measuring system was installed on the second batcher, due to the successes of the first.