Unlike flow in pipes, which can be stopped by a valve, flow in open channels cannot be stopped, it can only be diverted elsewhere. 

Referring to the diagram; by rotating a cylindrical section of the drain, the portion of diverted flow can be adjusted to limit the flow allowed to pass downstream.

When flow in the pipe increases to its limit, at (2), the chute

begins to rotate to discharge any further increase (3). Further rotation (4) is required as the flow increases (this is indicated in the centre-top drawing).  As the flow decreases (5), the chute rotation is reversed and finally returns to its parked position (6).

RotoChute was developed by Hymetrics to enable precise flow-control to be achieved, with a minimum of possible length of channel.

The picture shows a small RotoChute with drain bore of 150mm.  The unit was installed at the inlet to a small works to ensure that surge flows did not destabilise the treatment process.

Construction material is of grade 316 stainless steel.

This unit was designed to maintain precise control of flow to treatment, limited to 4 litres per second, against surges of up to 18 litres per second.

Inlet Works

On a small works, for example an RBC package plant, RotoChute can be installed by direct coupling to the inlet pipe.  Flow is diverted to a storm tank to be returned when the flow has subsided to normal levels.

It can be supplied as a package with integrated flow measurement using a V-Flume, usually in a trapezoidal or half-round channel.

Sewer Overflows

The chute of a CSO version has a bar-screen (not shown)  over the chute exit to retain debris within the sewer.

Brushes or water jets positioned top-centre above the chute, clear debris off the screen when the chute is periodically reversed.

Both versions are controlled by signals from flow or velocity sensors positioned downstream of the RotoChute.