Kiln Line, Cement Plant

In its cement plants in Lengerich, North Rhine-Westphalia, the Dyckerhoff Zement GmbH had the new “Ofenlinie 8” (Kiln Line 8) constructed between 1999 and 2001. It replaces the three old cement kilns and achieves a daily output of 3,700 t of cement clinker. The new technology requires about 15 percent less energy than the old facilities; furthermore, the exhaust emissions of the kilns were reduced by approx. 25 percent.

The “Ofenlinie 8” ensemble consists of numerous single structures, including an aggregates storage, a ballast silo, a raw meal silo, a conveyor belt tower, a raw mill building, a heat exchanger tower, a clinker cooler building, two clinker silos and rotary kiln foundations. As the cement plants borders on a residential area and is located close to the Teutoburg Forest, the architectural design of these buildings as well as noise protection were of particular importance. That is why primarily closed buildings as solid construction were planned, which are characterised by recurring stylistic features like protruding pilaster strips, rounded corners or slanted roofs. The most distinctive building of the facility is the 24.70 x 17 m large heat exchanger tower with its four circular corner towers. Its load-bearing structure consists of two U-shaped, 107.50 m tall reinforced concrete sections constructed using the slip-form method, between which steel platforms are positioned.

Four reinforced concrete ceiling plates distributed over the entire height of the tower connect the two U-sections with open sides and brace the structure. The 93.80 m high bucket conveyor tower and the 84 m tall cylindrical raw meal silo are interconnected via two above-ground passages and an underground channel. The silo consists of two separate levels for storing and mixing the raw meal, whereas two bucket conveyors in the adjoining tower ensure the transport of raw meal respectively stone dust to the blending silo respectively the kiln. Both buildings were also primarily constructed using the slip-form construction method.