Expérience de l'E.D.F. dans le domaine des prises d'eau de haute montagne à chasses automatiques

E.D.F. experience of self-flushing high mountain water intakes

¹ Chef du G.R.P.H. Loire - Saint-Etienne.
² Chef de Division au Service Etudes et Projets hydroélectriques, Direction de l'Equipement.
³ Chef du Service Etudes et Prospections. R.E.H. Alpes-Nord, Chambéry.

Résumé

E.D.F. have acquired sufficient practical experience of automatic water intakes to be able to consider the problem as practically solved. As a water intake and its automatic system form a single homogeneous unit, automatic flushing can only be worth while if all the components from the river intake to the flushing channel are working properly. The following parts of the structure are reviewed : (i) The river intake (Figs 2 to 8) ; (ii) The settling tank (Figs 9, 10 and 11) ; (iii) The sluice gate (Fig 12) ; (iv) The flushing channel (Fig 13). The three following automatic systems of comparable efficiency are then described : System A with a conical silt detector, a rocking weir and a finely balanced sluice gate (Gigs 14 to 18) ; System B with a weighing detector, a differential pressure gauge and relay amplifier and a hydraulically-actuated sluice gate (Figs 19 to 23) ; A composite system combining A and B. Three representative water intakes are then described, all of which are based on the principles described in the article (Plans n° 1, 2 and 3). The following advantage of automatic operation in the considered case are emphasized : (i) Reduced supervision cost ; (ii) Better feasibility ; (iii) Reduced water loss.