Effluent discharge at chocolate factory

RS Hydro has been granted a contract to install MCERTS approved flow monitoring equipment at a chocolate factory. The project is based on the flow of discharge from three pipes on the site carrying trade waste. RS Hydro has also been asked to install temperature and chlorine sensors.

The objective is to provide a continuous water monitoring system for all three points, which feed into a brook. Field engineers have elected to install Siemens Milltronics open channel flowmeters. The HydroRanger 200 open channel flowmeter was used in the first two and the Siemens OCM III open channel flowmeter in the other.

The Siemens HydroRanger 200 flowmeter provides an economical, low-maintenance solution. It uses proven continuous ultrasonic echo ranging technology to measure any water or wastewater up to 15 m in depth. The resolution is 0.1% and accuracy is 0.25% of range. This water flowmeter is set apart from other contacting devices, because it is immune to problems caused by suspended solids, harsh corrosives, grease or silt in the effluent. This all enables high accuracy and easy set-up, and minimises the time required for maintenance. These factors make the Siemens HydroRanger 200 an attractive water flowmeter for busy industrial applications.

Both the Siemens OCM III and the HydroRanger are high accuracy non-contact flowmeters for open channels. They calculate flow rate from the level of the head of the water, as it passes over a structure. RS Hydro has therefore suggested a stainless steel plate, which will sit inside the pipe. As the water passes over the plate, the flowmeters will be able to define the flow rate from the level of the top of the water using a pre-calculated formula.

The OCM III boasts adjustability - with logging facilities available from one log per minute, to one per day - and intelligence, taking daily recordings of minimum/maximum of temperature and flow rates, and the time they occurred, as well as the daily total.

Both the Siemens HydroRanger 200 and the Siemens OCM III are also certified for MCERTS. MCERTS is the Environment Agency's Self-Monitoring Certification Scheme: to provide a framework for consent holders under the Water Resources Act 1991 (WRA '91) to measure the flow of sewage or trade effluent to controlled waters and collect and report the monitoring data. Any flow over 50 m3 per hour must be monitored under this scheme, and the Siemens products have been proven to be reliable and accurate for this purpose.