Storm-water overflow channel for inlet to sewage works - has adjustable weir, outlet of which comprises circular aperture cut in thin cross=wall

摘要

Installation comprises open rectangular channel with a storm water overflow weir and a circular outlet aperture which is formed in a relatively thin cross-wall. This type of aperture is less sensitive to variations in impounded depths (i.e. through flow is a function of the root of the impounded depth) thus, promoting uniform feed to purificn. works. The weir is adjustable, being in the form of a slidable plate; and the outlet aperture discharges into a transition chamber. The downstream wall of the main channel may include U-notch for flow measurement, a shutter being used to bring either the V-notch or the aperture into use. The thickness of the downsteam wall may be less than one quarter of the aperture dia.