Sustainable compressed air system keeps tunnel tube 'pressurized'

The RijnlandRoute, the new road link between Katwijk and Leiden, is taking shape. Part of the project is the construction of a 2.25 kilometer long bored tunnel. To maintain the air pressure in the tunnel during drilling, contractor combination COMOL5 is using the most energy-efficient compressed air installation currently available on the market. A design by BOGE Kompressoren.

Today's most energy-efficient solution

As an established relationship of some of the combiners within COMOL5, BOGE was asked to collaborate in putting together a compressed air system to maintain air pressure in the tunnel tube during drilling. "The technical and financial aspects of the offer were satisfactory and convincing enough for COMOL5 to choose BOGE," says Olivier Matheron, buyer on behalf of the contractor combination. Ronald Engberts of BOGE adds: "During the engineering phase, we like to think along with you in order to use our compressors as efficiently as possible based on the needs and requirements. For COMOL5, this resulted in the most energy-efficient solution currently available on the market."

BOGE commissioned and adjusted the plant in late 2019, ensuring the compressors are running at the correct range. (Image: Guus Schoonewille)

Air pressure always optimal

The setup developed by BOGE for the RijnlandRoute includes three S-4 series screw compressors, as well as two DS350 compressed air refrigeration dryers. "With this setup, we can ensure that the air pressure is always optimal during tunnel drilling," says Engberts. "COMOL5 is also assured of a highly efficient installation and always has a backup due to this setup. As a 112-year 'young' German family business, we place great value on high quality and are fully committed to energy savings." The S-4 screw compressors are characterized by an innovative design concept that makes great strides in terms of noise reduction, serviceability and power input. Engberts: "All sound-damping panels are removable and all maintenance work can be carried out from two sides. The oil separator tank, drive motor and compressor block are all elastically attached to the base frame and thus effectively decoupled from vibration."

Substantial savings

The refrigeration dryers behind the S-4 compressors also follow BOGE's mission to save as much energy as possible. "The effective control of our DS350 refrigeration dryers ensures a very economical drying process of the compressed air. Pressure loss is no longer an issue. That means we can save up to 6% on every bar of air pressure," Engberts explains. "We commissioned and tuned the installation at the end of 2019 so that the compressors are running at the right range. By the way, that can be fully monitored by us remotely. Any malfunctions can also be monitored remotely. Because we have built in an extra backup on the RijnlandRoute, online monitoring of malfunctions is less crucial for this project. The installation is currently running to the client's complete satisfaction. That obviously makes us happy too. In any case, it is a special project for us as a company, because there aren't that many tunnels being built in the Netherlands," concludes Engberts enthusiastically.