Noske-Kaeser's New Ventilation System Protects Offshore Foundations

Hamburg based Noske-Kaeser, provider of innovative system solutions in air conditioning, ventilation, refrigeration, piping, firefighting and CBRN protection, has developed a new ventilation system to protect offshore wind turbine foundations from explosive gas mixtures. Several systems are currently in successful long-term tests with a renowned wind turbine operator.

Offshore piles are facing corrosion in saline sea water and need to be protected. Therefore special coatings based on galvanic anodes or external current (cathodic corrosion protection enriches the metal with additional electrons to prevent corrosion) are commonly used.

“By using cathodic corrosion protection systems up to 600 liters of hydrogen per day can arise in the lower, gas-proof areas of the foundation”, says Udo Habermann, responsible Senior Sales Manager at Noske-Kaeser. “Since the foundations experience no natural ventilation, an explosive mixture of gases can arise in the long term, which endangers not only the wind turbine itself but also the service crew working in the piles.” So far, there exists no other explosion prevention solution.

“To avoid the formation of such a dangerous accumulation of gases and for the simultaneous protection of man and material, we have developed an innovative ventilation system, which is intended particularly for retrofitting existing wind turbines”, Habermann explains.

Noske-Kaeser has developed the system in compliance with existing explosion endangered areas (Ex protection zones), the monitoring of the facility and the gas concentration in the foundation, the determination of the required air exchange and using existing openings in the pile. The low-maintenance ventilation system can easily be installed with an adhesive technology without any welding work. It consists of energy saving synthetic materials that are protected from strong wave actions. The technology is flexibly adaptable for all pile types such as monopiles or tripods. “Aeration rate and possibilities are calculated individually for each facility”, Udo Habermann says. The reliable monitoring and ventilation with the Noske-Kaeser technology lowers the Ex zone level for those piles from 1 to 2.