State-of-the-art bitumen storage.

Bitumen tank retrofit to an asphalt mixing plant

Großmehring | Bavaria, Germany

IAM Ingolstädter Asphaltmischwerke GmbH & Co. KG has operated an asphalt mixing plant at its site in Großmehring (near Ingolstadt) in southern Germany for many years now. During this time, the company has commissioned a number of retrofit projects from Benninghoven. The most recent task to be tackled was the renovation of the bitumen tanks. With this investment, IAM was looking to boost its storage capacity while increasing the flexibility of the plant with the aim of accommodating a wide variety of customer requirements in the future. The project would also reduce operating costs and improve the company’s environmental profile.

Before

Eroded insulation and horizontal tanks heated with thermal oil: the situation before replacement is a good example of the major potential that retrofits have for an asphalt mixing plant.

After

Optimal insulation and electrically heated: modern technology from Benninghoven means more efficient operations.

Quality asphalts since 1981

The asphalt mixing plant in Großmehring has been making high-quality asphaltic mixtures since 1981. These have been used for wear courses on highways and rural roads as well as urban traffic routes. IAM is part of the Geiger Group, which is a leading member of the German Asphalt Association (DAV). “This is why we are particularly interested in producing high-quality asphalts and ensuring compliance with applicable quality standards,” says Rainer Hohenwarter, Geiger Group Co-CEO and Member of the DAV Executive Committee.

To ensure its plant kept pace with technological advances, the Geiger Group entrusted Benninghoven with a number of retrofit projects over the years. These have included exchanging the burner, installing a new dryer drum and integrating a user-friendly Benninghoven control unit.

“With a Benninghoven retrofit, we ensure that we consistently supply a high-quality product, even if recipes change.”

Rainer Hohenwarter, Co-CEO
Geiger Group

Electrical tank heating –
zero local emissions

The Ingolstadt-based asphalt mixing plant has now used the project to replace the bitumen tank – along with all its piping – to switch the heating from thermal oil to electricity and expand the varieties of bitumen stored at the plant. Calculations made by the retrofit experts at Benninghoven’s Technical Office had revealed that this type of heating, which produces no local emissions, was the most advantageous for the tank configuration selected.

“We now have tanks with greater storage capacities and some of these are now equipped with a mixing nozzle or an agitator. This makes as much more flexible, because we can now also store polymer-modified bitumen (PmB). This means we can produce a significantly larger range of recipes at the touch of a button,” explains Herbert Geiger, son of the company founder and longtime Chief Executive Officer of the Geiger Group.

Two of the new tanks have a volume of 60 m³, with three others offering a volume of 100 m³. This is considerably more than before. The increased storage capacity also benefits flexibility and production reliability in particular, since delays to inbound deliveries of bitumen can be more easily compensated for. Thanks to the improved insulation that IAM ordered for the tanks, all five tanks are now better at maintaining a constant temperature while using less heat energy. The installation uses a 300 mm-thick layer of mineral wool, shielded by an outer layer of profiled sheeting.

The prior situation clearly showed the need for modernization.

To keep the asphaltic mixture in a homogenous state and avoid the separating-out of some mixtures such as polymer-modified bitumen (PmB) in the tank, agitators and mixing nozzles are also provided.

Until the last piece is in place: a turnkey retrofit

The Geiger Group contract involved a lot more than simply producing and supplying bitumen tanks. For bitumen tank integration jobs like the one in Bavaria, the “extra work” was the biggest challenge. All of the piping had to be connected to the plant infrastructure and the cabling also needed to be wired up to the plant control. This is why Benninghoven always offers customers an all-in-one package for retrofit projects: From initial consultation and planning through to installation and commissioning, the Benninghoven team handles everything until it is all working properly, and completed to the satisfaction of both the client and their employees.

“At our site in Großmehring, any work that involves laying new foundations must be avoided as far as possible. This is also why we’ve already done a lot to optimize things with the Benninghoven Retrofit team. “Thanks to their systems, we can ensure that we consistently supply a high-quality product, even if recipes change,” comments Rainer Hohenwarter.

Highlights of the Benninghoven bitumen tanks

  • Electrical heating – no local emissions
  • Less energy consumption
  • Low operating costs
  • Highest operational reliability with state-of-the-art systems
  • Effective insulation with 200 mm (optional: 300 mm) layer of mineral wool
  • With agitator or advanced mixing nozzle
  • Nominal capacity 60 m³, 80 m³, and 100 m³
  • Versions with one or two chambers