High temperature resistant geomembrane in New Zealand
Water pipes rely on high temperature resistant geomembrane
The Lake Taupe with a length of 40km and a depth of 400m is located in the middle of the northern island of New Zealand. Near the lake there are wells which bring boiling water to the surface. This water is pumped to a nearby power station and is used to generate electricity. Afterwards the water has a temperature of 80°C. Due to the high temperature it cannot be released into a river or a lake because all animals would die. Therefore it is pumped into an artificial lagoon and kept there until it reaches a temperature in the range of 25°C. The lagoon has a surface area of about 7000m².
Normal HD-PE is not suitable for this application due to the high temperature of the water. Consequently a high temperature resistant PE material was selected to produce geomembranes for this special application.
Multi layer sealing system
- Earth work
- Geotextile (protection)
- Regular geomembrane made from HD-PE (1.5 mm)
- Swell-able geotextile
- Geomembrane made from high temperature resistant material (1.5mm)
PE material for elevated Temperature
Special PE materials have been used for hot water pipes for many years. This technology has now also been applied for geomembranes. Compared to standard HD-PE geomembrane this new type of material has an increased life-time at elevated temperatures. Consequently this material was selected for lagoons with a water
temperature of up to 80°C.