When this came out by email to members I thought of trying to share it with those here who like the technical aspects of projects. I decided it was too long and complicated though, and copyright anyway.
It is now on their website and is a good illustration of intelligent engineers trying to get the best out of their kit, in this case making the best use of low river flow:
Well worth reading...The Practice So, that’s the theory and speculation but what about practice? Well, a week or so ago, the sun was shining and under a gorgeous blue sky we decided to “have a play” at only partially opening the sluice gate and see if there was any impact. The screw was running at about 3 rpm and generating about 3kW at the time.
In fact there was an impact—we did get some extra power (stable operation at 10KW instead of 3KW), hardly any water leakage and a remarkably quiet screw. So what happened? As expected, the screw speed increased to restore the water flow back to its original flow rate which had decreased as a result of the increased head loss across the partially closed gate. The operating forebay tank level dropped. However, this did not result in diminished torque. Since power is the product of screw torque and rotational speed, more power was generated.
https://www.congletonhydro.co.uk/congle ... ter-april/
... finishes with advance news of the next project: an appeal for committee members and info that it will be on the big weir at the foot of the town and also have pv on nearby buildings too.