Official dealer Bulgarcom delivers a Linden Comansa 21LC290 tower crane to build two tall chimneys in a sulphuric acid plant.
The Aurubis Group, one of the world’s leading copper producers, owns a plant near the Bulgarian town of Pirdop. As well as copper, this plant also produces sulphuric acid as a bi-product. This chemical compound is highly used in the petrochemical and metallurgic industries, and mostly on the Fertilizer Industry.
The new outgoing gas cleaning facilities, each one formed by a tall fiber-glass pipe and a supporting steel structure, are part of “Aurubis Bulgaria 2014”, a € 44.2 million worth project launched by the company in 2011. The main goal of the project is to improve the environmental protection and increase the productivity. For such a special development, Bulgarcom Ltd., Linden Comansa’s official dealer, delivered a new 21LC290 tower crane from the Spanish manufacturer, with maximum load capacity of 18 tons.
Linden Comansa 21 LC 290
At the beginning of April 2014, Bulgarcom’s technical team finished the initial assembly of the 21 LC 290. With a freestanding height of 63.1 meters and jib length of 40 meters, the crane was ready to start working on the construction of the steel structure of the tallest chimney, with a final height of 125 meters. This structure was assembled on the ground in modules of up to 14 tons that the crane lifted to be easy connected at the top.
In June, as the construction gained in height, the crane was tied to the steel structure with a bracing at the height of 49 meters. Bulgarcom’s erectors team then used a Linden Comansa J2-10 cage to climb the crane to a height of 101.6 meters. These manoeuvres were not easy for Bulgarcom’s team, as the plant is close to the Balkan mountain, where the weather conditions change relatively fast. “We had many thunders, and the constant changes of the wind were a big challenge for all of us”, said Tenko Tenev, Chief Technician of Metalik AD, the contractor company that is using the tower crane for assembling the chimneys.
In July, another tie-frame was added at the height of 88 meters and the crane was climbed again to reach the final height under hook of 134.6 meters. At such height, the 21LC290 18t was able to finish with the construction of the chimney’s steel structure and with the installation of the heavy modules of the pipe by August. “The construction of the chimney was very fast, partly because of Linden Comansa’s Effi-Plus system”, says Nikolay Nikolov, Managing Director at Bulgarcom. “The standard 50kW hoist winch works at a high speed, up to 150 meter per minute, which allowed us to accomplish a very efficient job, especially during the hoist down procedures”.
In October, for the second stage of the project, the 21LC290 tower crane was disassembled and erected at another part of the plant to build the second chimney, with a height of 120 meters. The crane is currently working with the same jib length (40 meters) at a height of 101.6 m and will have a final height under hook of 123.6 meters.
Bulgarcom Ltd. was established in 2002. It is one of the leaders of the Bulgarian market for renting lifting equipment, scaffolding and formwork systems. Bulgarcom has a rental fleet of more than 70 tower cranes (up to 48 t lifting capacity), mobile cranes (up to 200 t lifting capacity), hoists and work platforms.