Flow Weir/Divider - Discharge-Channel flow-meters

FLOW WEIR/DIVIDER

When there is the need to accurately measure the flow-rate of large streams of dirty effluents, no traditional metering system is reliable enough. When predictive control technology needs to be employed to boost heat recovery efficiency, a metering system for dirty effluents is a must. Furthermore, there might be the need to subdivide the total flow into many separate, proportional streams.
POZZI has developed a special stainless-steel AISI 316, boxed-structure weir designed to be mounted inside any concrete channel.

It comes with the following accessories:

600mm weir blade with adjustable height and 45° chamfer;
embedded pressure trasmitter;
temperature compensating device;
flow converter/calculator.

Optionally, the unit can also be used as a proportional flow divider with up to:

5 vertical flow-divider blades with adjustable lateral positioning to obtain 6 proportional streams out of one nappe.
6 pipe stub spigots of appropriate diameter for connection to 150mm HD polyethylene piping.

Flow measurement is accomplished by a transmitter programmed to convert a pressure reading into units of volume per time, as liquid passes through a flume or weir in an open channel. The flume is a specially shaped portion of the open channel, with an area or slope that is different from the channel’s slope or area. The weir resembles a dam placed across the effluent channel, positioned so that liquid can flow over it.

In this way, flow-rate measurement is much less expensive than with other methods.
Upstream the weir blade, a quiet pool is created to guarantee sub-critical flow conditions. The pressure measuring gage will give a reading of the height of the drop-off which, in turn, is used to derive a quite accurate reading of the instant flow-rate.

Optional flow divider:
Downstream the nappe, up to 5 vertical blades can be mounted in the receiving pool, thus creating up to 6 confined spaces which convey water to the 6 outlet spigots to be connected to different exchangers. This arrangement creates a rather accurate proportional flow divider, quite adequate for our purpose of conveying a proportionally equal flow-rate to each exchanger in case the total flow-rate decreases.