Anaerobic Digester Tank Lining, Tewkesbury, Gloucestershire
THE PROBLEM – Anaerobic Digester Tank Lining, Tewkesbury, Gloucestershire
The new anaerobic digester site required the protection of its four tanks – reception tank, two digesters and one digestate store. We were also responsible for achieving gas tightness of the tanks. The feedstock for the site is food waste collecting from surrounding councils and commercial premises, creating a much more aggressive environment within the tanks.
THE SOLUTION – Anaerobic Digester Tank Lining, Tewkesbury, Gloucestershire
We proposed the application of the same tank lining system that we have used extensively throughout the biogas market. Initially all surfaces to be coated were prepared by method of high pressure water jetting to remove surface laitance and contaminants to ensure excellent adhesion of the new tank lining. The waste wash water was pumped out and the tanks heated to dry the concrete and obtain the correct climatic conditions for coating application.
Once prepared all surfaces being lined were primed using Remmers Epoxy MT100 damp tolerant epoxy primer applied by method of airless spraying back rolling.
All roof to roof joints were then bridged using a foil debonding tape and the roof to wall joints sealed using a polyurethane jointing compound. To achieve gas tightness Corrolastic HT highly chemical resistant polyurea tank lining material was applied to all joint areas to a thickness of 2mm.
Remmers epoxy universal was then applied throughout the tanks in two coats of contrasting colour by method of airless spray to a thickness in excess of 1mm. This flexible and crack bridging epoxy tank lining material has over 20 years of case histories in the biogas market.
Finally the tank linings were checked for pin holing using a DC holiday spark tester and rectified where found.
The weather conditions made the project quite a challenge due to the low ambient temperatures which meant additional indirect oil fired heaters were required on site.