Spirax Sarco has launched a Turbidity Monitoring System for detecting non-conductive contaminants such as fats, oils and greases in condensate, enabling steam system operators to recover substantial amounts of energy that would otherwise be lost.
Such contaminants, if accidentally released into condensate, could cause the boiler to overheat, requiring a lengthy shutdown for chemical cleaning, or at worst, causing boiler failure.
To eliminate this possibility, some operators may discard hot condensate rather than recycle it as boiler feedwater. With condensate containing around 25 per cent of the useful energy in the original steam, recovering it can substantially reduce water, energy, effluent and chemical treatment costs.
The Spirax Sarco Turbidity Monitoring System helps operators to re-use condensate by providing real-time monitoring, raising an alert if contamination rises above a set level, allowing the tainted condensate to be diverted to drain immediately rather than fed into the boiler.
The Turbidity Monitoring System can also be used to monitor the quality of other water sources, such as mains, demineralised and reverse osmosis supplies. This makes it suited to applications where water quality is paramount, such as cleaning-in-place and sterilisation-in-place stations in hospitals or food and drink manufacturing.
The Turbidity Monitoring System comprises a turbidimeter and a converter. The turbidimeter uses light in the visible and ‘near infrared’ range to penetrate the fluid medium. Four sealed photodiodes detect any light scattered by contaminants. A fifth photodiode measures unscattered light to provide a reference measurement. This innovative ‘dual channel’ method compensates for colour and other variations in the water to provide more accurate and more reliable results than conventional single channel systems.
The converter comes with four fixed and one variable measuring range, allowing operators to tailor turbidity levels to specific process parameters. Two independent set-points can be configured to determine when the required turbidity thresholds are reached, to control the diverting and discharging of condensate when contamination is detected. The converter has a three-digit LED indicator that displays the turbidity level as a percentage of the selected measuring range. Contamination can be displayed in parts per million (PPM).
Steam system operators can also use the system to free up valuable resources as it helps to meet national and international standards for unmanned boiler operation. For example, all shell boilers operated in the European Community must comply with the harmonised standard BS EN 12953, which specifies maximum contamination levels for boilers running unsupervised for periods of 24 to 72 hours.