Twin-shaft batch mixer from BHS-Sonthofen proves its worth in a major project.
Europoles delivered 618 supports made from white, high-strength spun concrete for the third largest mosque in the world in Algiers. The pole manufacturer from Neumarkt produced the concrete for the up to 34 m high and up to 34 t columns with twin-shaft batch mixers from the BHS-Sonthofen DKX range.
At present, a Muslim community in the Algerian capital is erecting the Great Mosque of Algeria at a cost of around 1.1 billion euro. The prayer room is a vast cube with a capacity of up to 35,000 people. The production of in total 618 octagonal concrete supports for the imposing structure was not an every-day project even for Europoles.
The 32 largest of the 618 octagonal spun concrete supports made from high-quality white concrete have three parts, a total length of 34 m and a diameter of 1.62 m. By September 2015, Europoles will have sent the last columns on their way to Algeria.
For this project, Europoles needed a new mixer, since the mixing times with the existing planetary mixers would have been much too long. Furthermore, a separate mixer needed to be used for the extremely delicate white concrete in order to avoid contaminants.
However, the new mixer was not required just for the mosque project: The interest in high-strength and ultra high-strength concretes is rising constantly and Europoles wanted to use the investment in the new mixer to ensure that it is well prepared for future projects. High-strength concretes need to be mixed particularly intensively to achieve good homogeneity. For this reason, the focus is on a short mixing time as well as the correct mixing procedure, since the new system needs to be able to produce up to 20 m³ of concrete per hour.
Due to the high mixture homogeneity requirements, several mixing procedures were straight away out of the race already during the market research phase. In addition, the new mixer needed to be integrated into the current building without any need for significant conversion work. This meant that a compact mixer was the only option – but it still needed to offer a high throughput. Some machines were ruled out because the available installation space was insufficient and extensive conversion work would have been required.
Thus, the twin-shaft batch mixers from BHS-Sonthofen reached the shortlist. The Europoles plant technology department finally decided upon the most powerful and fastest mixer that could be accommodated in the existing installation space – a DKX 1.25 with a rated output of 1.25 m³ of hardened concrete per batch. Due to its high filling degree, this mixer type is extremely compact while providing the required throughput. As a result, little alteration was required to the existing facility.
One reason for the decision in favor of the BHS mixer was also the recommendation of the adjacent concrete plant, which has been using a twin-shaft batch mixer to manufacture UHPC concrete to construct bridges and wind turbines for quite some time now.
Because the schedule for the delivery of the columns for the mosque was already fixed, the time line for the delivery and commissioning of the mixer was extremely short. Europoles placed the order with BHS-Sonthofen in April 2013, and just six months later, the new facility had supplied the first lot of concrete.
On a normal production day, the new facility mixes up to 16 batches of this challenging concrete per hour, achieving an output of just under 20 m³ in this time. For the mosque project, up to four columns per day have left the plant at peak times, each of them with a weight of up to 30 t.
Experiences from the mosque project indicate that the quality of this high-grade concrete recipe is extremely good. Even at peak times, the requirement for short mixing times is met.
Bernhard Matschiner, responsible for the upgrading of the mixing plant for the mosque project, is pleased with the results so far: „Beforehand, we were only able to produce white concrete in very limited quantities, since the mixing times using planetary mixers were much too long. The homogeneity of the concrete produced with the BHS mixer is excellent and it works extremely reliably with high availability. We can now also reliably produce large quantities of high-grade UHPC. Thanks to the new mixer, we’ve been able to significantly improve our market position – especially with regard to our competitor material, steel. In the future, we will be offering products whose quality and price are superior to those of steel.“
Unlike pan mixers and planetary mixers, which mix in two dimensions only, BHS twin-shaft mixers generate the three-dimensional movement of the entire mixture. In addition, intensive material exchange takes place in the turbulent overlap area of the two mixing circuits. Furthermore, these mixers offer high production variability, since even small batches can be produced extremely homogeneously. Moreover, they boast cost-effective, specific energy consumption, since they optimally convert the supplied energy into the intensive relative movement of the entire mixture.
BHS twin-shaft batch mixers are significantly more compact than other mixer systems, which means that mixers with a higher throughput than mixers that use other procedures can generally be installed in the available installation space when plant modifications are made.
BHS-Sonthofen is an owner-operated group of companies in the machinery and plant engineering field, based in Sonthofen, Germany. The company offers technical solutions for mechanical process engineering with a focus on mixing, crushing, recycling and filtration. With more than 350 employees and several subsidiaries, BHS-Sonthofen has a global presence.
The mixing technology division produces batch and continuous mixers and offers a full range of process technology for mixing. The twin-shaft batch mixer, which is considered a global benchmark in the concrete industry, is an important product.
For more information, see www.bhs-sonthofen.de.
Europoles GmbH & Co. KG is Europe’s leading manufacturer of poles, supports, and load-bearing systems. Europoles offers standard and special solutions and turnkey systems including all services from consultation to demolition. The company uses proven and innovative technologies and materials – concrete, steel, and glass-fiber reinforced plastic. Europoles is characterized by its many years of experience, high level of technical solution competence and management of complex projects in close collaboration with its customers and partners. Europoles GmbH & Co. KG serves the infrastructure markets for transport, energy and telecommunications as well as creates applications in lighting, structural engineering and special construction. The geographical focus is Europe, the Middle East and North Africa, and on expanding into attractive markets around the world. Europoles is a company of VTC Industrieholding GmbH.
Based in Neumarkt in the Upper Palatinate, Germany, Europoles GmbH & Co. KG has firm roots in the region. Nevertheless, Europoles is an international company with nine production facilities in Germany, Poland, Switzerland and Oman. With numerous German and international sales subsidiaries as well as European and Middle Eastern sales partners, the company always has a presence where its customers need it. At present, Europoles GmbH & Co. KG has around 1,400 employees and an annual turnover of around 200 million euro.
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