New flume tank
Cedre’s flume tank or “polludrome” is designed for pilot-scale simulation of conditions in the open sea, rivers or on the shoreline. This unique experimental tool also aims to recreate different phenomena which are liable to occur in the natural environment. These simulations are dedicated in particular to the study of the behaviour of chemicals and petroleum products during the first hours after they are spilt, but other applications have also proved to be interesting. The flume tank can thus be used to assess response strategies such as treatment by dispersants, the use of sorbents in rivers or recovery systems at the prototype stage through small-scale testing. The flume tank or “polludrome” which Cedre acquired in 1997 was used to conduct many different behaviour studies on chemicals and oils, in particular in the event of real spills such as that of the Erika in 1999. After fifteen years of intensive usage, this tool was in need of replacement. The opportunity was taken at this point to conduct an investigation in order to improve simulation conditions and facilitate its use.
Installation of the flume tank on Cedre's premises
Characteristics
This experimental tool, made entirely of stainless steel, is installed in an air conditioned room, where the temperature can vary between 1 and 30°C. The volume of seawater contained in the tank is 7 m3 and the water depth 90 cm (the flume is 140 cm high by 60 cm wide). The frequency and height of the waves generated by the system can be altered (typical conditions: 3 second frequency, 15 cm in height). Sunshine is simulated by two 2000 W units which recreate the spectrum of natural light, and surface slicks are regularly exposed to this light during their circulation in the ring (creation of current with a propeller on the tank floor). Air circulation at the water surface is simulated by a wind generator and harmful vapours are evacuated from the air-conditioned room by an extraction system.
Usage
Since 1999, over forty different petroleum products of all origins have been analysed in the flume tank in order to study their weathering. A database was thus created in a bid to predict the behaviour and fate of a petroleum product spilt at sea according to its initial properties. In the event of a spill, the flume tank can be immediately mobilised, as soon as a sample of the product in question is received, to study its behaviour and establish response strategies. This mobilisation was necessary for example during the Erika and Prestige spills. Furthermore, specialised tests have been conducted in the flume tank to evaluate new inventions, such as model oil spill response vessels, or to assess the behaviour of bulk solids (coal) or acids (for example phosphoric acid during the Ece incident).
Ring tank
View of the inside of the tank
Release of heavy fuel oil in the flume tank
Emulsion in the flume tank.
Photo source: Cedre
Last updated: 20/10/11