Large tanks installed for a paper mill

The Progroup Group is building one of the largest paper factories in Germany in Sandersdorf-Brehna/Saxony-Anhalt. The factory is also taking ownership of a large boiler plant for the reprocessing of recycled paper. The necessary equipment for this was delivered by Viessmann Industrial Boiler Solutions GmbH from Dillenburg/Hessen. SCHOLPP took on the task of bringing in the 82-metric-ton boiler plants, which called for a powerful mobile crane to be prepared as well as the special preparation of the crane site.

For economic and environmental reasons, modern paper production tends to be combined with the reprocessing of waste paper. And this concept is also followed by Progroup AG at its new factory construction project in Sandersdorf-Brehna. Hot water is used to soften the waste paper for the recycling process. The thermal energy needed to heat the water will in future be provided by four large superheated steam boilers. Progroup ordered these plants from Viessmann Industrial Boiler GmbH in Dillenburg, a company specializing in the economical supply of steam, power, heating and cooling for industrial systems. Viessmann offers comprehensive system solutions for efficient energy systems that make an important contribution to the reduction of operating costs and pollutant emissions, thereby helping to create competitive advantages.

Heavy installation near an embankment: Lifting capacity of up to 82 metric tons

Thanks to its many years of experience with large tanks and energy systems for industrial plants, SCHOLPP was commissioned to bring in the boiler plants. The project involved bringing in a total of four boiler plants, each weighing 82 metric tons and consisting of an economizer and a superheater, and two feed water tanks weighing in at eight metric tons each. With a diameter of three meters and a height of nine meters, the plant dimensions weren’t actually much of a challenge. All of the lifting was carried out via the opened roof of the paper mill building shell. This required the crane to be set up in the vicinity of an embankment. In order to absorb the resulting ground pressures, the ground firstly needed to be professionally prepared. Due to the huge weight of the crane and the lifting gear, it was absolutely essential to ensure that the crane site remained completely stable over multiple days and regardless of the weather conditions.

Time-saving bringing in: Mobile crane with luffing fly jib

A 700-metric-ton mobile crane with luffing fly jib was used for this project. The SCHOLPP engineers opted to use this crane so as to avoid having to convert the 500-metric-ton crane that had been planned and that was adequate for the work being performed. This option required less preparation work and saved a lot of time. All four boilers were lifted in via the open roof and then precisely positioned onto the designated support structure. The feed water tanks also entered the building via the roof. They were placed onto a platform at a height of around 15 m, and were then pushed horizontally underneath the closed building roof using trolleys and grippers.

Risk of wind susceptibility minimized thanks to clever maneuvering solution

The bringing-in process, however, was not as simple as it first appeared. The components had to be threaded into the building structure at a height of around 20 meters, with longitudinal roof beams to contend with. The available space was tight in relation to the size of the components. The main difficulty when performing this maneuver is always the wind susceptibility of this type of large vessel. Even the gentlest airflows can cause large boilers to rotate during lifting or pivoting. To minimize this risk, the SCHOLPP fitters attached 60-meter-long special cables to the boiler tanks. This made it possible to manually stabilize the tanks during the lowering process – a safe solution combining crane and operator with minimal cost. The project was successfully completed within a week.