Interview: New energy-efficient compressor installation for voestalpine Polynorm

Saving energy through sustainable and intelligent solutions

ALUP GrassAir has delivered an energy-efficient compressor installation at voestalpine Polynorm in Bunschoten. Because of the long customer relationship with GrassAir Compressors and the products of ALUP, voestalpine Polynorm chose for a new ALUP GrassAir compressed air system that delivers significant benefits. These benefits include heat recovery, lower maintenance costs and lower energy consumption. The compressed air system supplies the entire plant with 6 and 10 bar compressed air via a central pipeline system.

Compressor installation

Screw Compressor installation at Voestalpine Polynorm

Upgrade compressed air system

The new compressed air system replaces the 4 old compressed air stations: 2 stations for 6 bar compressed air and two stations for 10 bar compressed air. These 4 stations contained a total of 12 compressors of which some were older than 25 years. Given this age, the reliability decreased and the maintenance and operating costs increased. Besides that due to the arrival of a new press line and the expansion of the assembly department there was a need to expand the capacity of compressed air.

Heat recovery

The result is a new compressed air system consisting of a total of 7 compressors, 4 machines for the supply of 6 bar compressed air and 3 machines for the supply of 10 bar compressed air. The choice has been made to place the 7 new compressors close to each other so the control units can be adjusted as optimal as possible. Due to the central positioning, maintenance can be carried out more efficiently. Furthermore, this solution offers the possibility to make maximum use of the heat released during the production of compressed air. This heat is used to feed the boiler, which is placed next to the new compressed air system, through the heat exchangers. This boiler heats among other things the production halls and the offices. The system is also built in a way that, if necessary, the 10 bar machines can supply air to the 6 bar air network via an air regulator.

Energyrecovery installation Voestalpine Polynorm

The new installation pays for itself within three years.

voestalpine Polynorm

Payback period of 3 years

When installing a new compressed air network, ALUP GrassAir also always looks at the TCO (Total Cost of Ownership) and potential payback period of the compressed air system. Because of the re-use of the heat released during production of compressed air, the lower maintenance costs and the 7 new compressors consuming considerably less electricity than the 12 old compressors, the investment in the new compressors by voestalpine Polynorm pays for itself within 3 years. On an annual basis, expressed as the number of cubic meters of natural gas equivalents, over 192,000 m3 of gas is saved. The project is therefore granted an environmental subsidy by the Dutch government as it meets the requirements of a so-called CIP Eco-Innovation project. With this investment also a reliable central compressed air system was realised with sufficient capacity for the recent enlargements.