The Problem
The operator of a large public building was experiencing cooling issues resulting from low flow and blockages in the chilled water network. Water quality samples indicated high levels of suspended solids.
The facility was live, therefore traditional flushing methods would have led to disruption to the facility’s operations.
Solution
A Dosafil Duo S+ side-stream water conditioning device was installed using a 5 micron filter bag. This was combined with a chemical treatment programme designed to clean the system online, without system shutdown or unnecessary water waste.
Water quality sample points were selected at the Dosafil Duo unit and in a sensitive equipment storage room, which had been identified as an area experiencing low flow and poor performance.
After 4 Weeks
- Chemical analysis and visual inspection indicated that large amounts of fouling had been mobilised and removed from the system.
- Water quality samples at the Dosafil unit showed significant improvement in visual quality and reduced iron levels and settleable solids.
- Water samples in the storage room initially showed a visual improvement after 1 week but deteriorated and indicated a high level of suspended solids. This was to be expected, with the application of dispersant chemicals to mobilise the solids.
- Microbiological results did not raise concern.
- The filter bags were reduced to 1 micron to further increase the rate of suspended solids removal and improve water quality.
After 6 Weeks
- Significant improvements were identified in visual and water quality analysis.
- Humidification units which had been in alarm for 3 years due to poor water quality, had not been in alarm since the Dosafil Duo S+ was installed.
- A solid-paste molybdate inhibitor was added to offer increased protection.
- The Dosafil Duo S+ installation was made permanent.
- A maintenance programme was agreed to replace the filter bags every quarter.