In the concrete sector, the preparation of concrete – the environmental-friendly construction material with a future –takes place in a wide range of intensive mixers. Trough mixers in the form of single- or double-shaft mixers are frequently used, as well as pan mixers with stationary or rotating mixing containers. Beton Röser operates with a pan mixer with a stationary mixing container, as well with an intensive mixer with rotating mixing container powered by a vertically supported agitator.
Since 2014, the concrete constituents are prepared by the TuneMixx mixing tool system (Fig. 1). Conversion to this system resulted in several very positive changes: a) an adjustment of the grading curve of the proportions of particle sizes, which enabled the use of more favorable aggregates, b) noteworthy savings in binders and admixtures, c) an improved mix quality and d) considerable fewer downtimes due to rapid exchange of the wear parts on the agitator.
Beton Röser successful for over 60 years
The company Beton Röser GmbH + Co. KG, in Obersontheim, Germany, had originally used an inclined mixer from Eirich with a conventional agitator for preparing the concrete mix. Progressive wear necessitated the purchase of a replacement. All the innovations involving the TuneMixx mixing system (Fig. 2) that the company Krauskopf had presented a few weeks previously had impressed the Managing Director, Wilfried Röser, and had favored the decision to give the new development a chance for testing under actual production conditions.
Beton Röser is a company that has been successfully run by the Röser family for over 60 years for concrete products, which provides a broad range of products for wastewater technology. The company philosophy, apart from cooperation based on partnership and trust, is strict emphasis on the quality of its concrete. This it achieves by complying with the applicable standards and values, constant adjustment to increasing requirements and application of the latest technologies.
The design of the TuneMixx is primarily oriented to the effective diameter, the overall length of the mount and the number of mixer blade levels of the previously used agitator. In the course of the first two years of testing, the wear protection was gradually developed in keeping with requirements. Long-term testing at Röser enabled fundamental optimization of the inner clamping system of the TuneMixx, as well as developments for seals, wear-protection covers, bottom tools among many others.
The greater specific mix energy resulting from the geometry of the mixing blades resulted in notably shorter mixing times soon after commissioning, and most positively influenced the most diverse characteristics of the fresh concrete. The more intensive mixing of the four-material system permitted an adjustment of the grading curve to enable the use of coarser and therefore less expensive aggregates. At the same time, a shift from dry- to wet-mixing time took place, as evidenced by better mix quality. The fines content was reduced to virtually zero, so that no excess powder had to be additionally bound with cement. The savings in binding agent and aggregates, due to a possible adjustment to the range of particle sizes had a positive effect on the production cost, without affecting the high quality of the concrete. The more intensive mixing of the concrete moreover resulted in reduction in the overall mixing time and, consequently, increase in the throughput.
Successful market launch of TuneMixx
The TuneMixx mixing tool system, however, offers even greater savings potentials: simple turning, changing and exchanging of the mixing blades, for example, enables optimal wear of the mixing blades, which can amount to annual savings of 40 %.The removal of wearing parts in direct contact with the product – e.g., mixing blades, bottom tools or wear protection covers – can be carried out within minutes in accordance with the basically required cleaning work. This significantly reduces downtimes and, accordingly, production downtime costs.
Influence of process-engineering parameters through preparation with a TuneMixx, as practiced by Röser, has also in other companies given way to the hygiene factor involved in a rapid-change system. The quality of the mix, the throughput and reduction of the temperature effect through shorter mixing times have been essential factors for many plant operators to decide in favor of mixing tools from the latest generation.
The successful market launch of the TuneMixx mixing system, with its approx. 35 units - not just in concrete production-, has been followed by great success. The company Krauskopf is very grateful that managers with a penchant for innovation such as Wilfried Röser, who give start-ups with good ideas a chance for successful implementation.