Pipe flush using the HB150

Siltbuster responded rapidly to an urgent callout to a hydro-electric power generating facility in North Wales. The facility produces green energy by harnessing the power of water flowing naturally from a hilltop lagoon, down the hillside, and into turbines which spin to generate electricity. The water then discharges into a nearby river.

On this occasion, due to low water levels in the lake, the flow had begun to draw down sediment and other contaminants which collected in low sections of the pipeline. The contaminated water was not safe to be released into the environment, and needed to be treated before it could be discharged.

There was a need for an urgent response, because the clogged pipes were limiting the facility’s capacity to generate electricity. Siltbuster Area Sales Manager James Baylis attended the site to scope the job, taking and testing samples to determine the most appropriate solution.

A high flow of around 110m3/hr was needed to flush the pipe properly. Because of the need to deploy quickly and with minimal impact on the environment, the Siltbuster team looked for a solution with the smallest possible footprint, minimal construction on site, and reduced transportation requirements.

Field sample testing indicated gravity-settlement alone would provide sufficient improvement to the water quality and provide the client confidence to safely release the treated water to the environment. This meant there was no need to add flocculants or coagulants into the process to help particles settle.

Pumps provided by Selwood, Siltbuster’s sister company in the Workdry International Group, were used to transfer the contaminated water into the treatment system from a single six-inch diameter hose.

The water was treated in Siltbuster’s new HB150 lamella clarifier unit, designed and manufactured at Siltbuster’s headquarters in Monmouth. In a lamella clarifier, water flows upward between inclined plates. The solids settle on the plates and slide down into hoppers in a sludge collection area where they can safely be removed.

The HB150 is essentially three clarifiers in one, giving effective treatment with high capacity, with advantages including:

• Faster deployment and installation
• A single lift for the unit and single lift for the walkway
• No manifold or interconnecting pipework required – a neater solution, fewer trip hazards
• A single sludge pump is needed to service three hoppers
• Fewer vehicles needed for transportation
• The solution featured actuated valve sludge hoppers, controlled by intelligent sensors,
• which automatically open and close valves to automatically de-sludge the system, reducing the need for manual intervention.

Before treatment, the water contained total suspended solids of 2,753mg/l.

After treatment, the system achieved 707mg/l – while maintaining 110m3/hr flowrate!

Following the process, the treated water was combined with clean sluice water, which further diluted the low levels of solids remaining, before being safely returned to the river.