BHS-Sonthofen optimize crushing at Dachser
Rotor impact mill and control system from a single source boosts productivity and efficiency
GERMAN building materials suppliers Dachser Fertigbeton-Kieswerke are currently expanding and optimizing their gravel plant in Türkheim by integrating a second RPM 1113 rotor impact mill from BHS-Sonthofen (BHS). In addition, BHS supplied the complete control system to ensure seamless co-ordination of the two machines, making the plant easier to operate and increasing productivity and efficiency.
For more than 60 years, Dachser have been reliably supplying numerous construction projects with building materials such as ready-mixed concrete, sand, and gravel. At their Türkheim site, excess gravel is used to produces a high-quality 0-4mm sand for concrete production.
‘Since we blend the crushed sand with natural sand, the resulting grain shape must be as close as possible to that of natural sand,’ explained Michael Zacher, head of technology at Dachser. ‘Previously, this task was accomplished using rod mills. However, these proved to be energy intensive at low throughput rates.’
Since 2019, a BHS-Sonthofen RPM 1513 rotor impact mill has been crushing the material to the required particle size. This high-performance vertical-shaft impact mill, which is employed by Dachser in a customized configuration, is particularly suitable for crushing all low-to-medium-abrasive minerals.
To keep up with growing market demand, the company decided to further expand its plant in early 2023. Based on the positive experience with BHS-Sonthofen, they decided to replace the remaining, outdated rod mill with a new BHS rotor impact mill.
In the case of the RPM 1113, Dachser opted for a bottom-mounted drive for easier maintenance access, and a modified, elevated machine housing with optimized flow performance. In close co-operation with Dachser, BHS carried out the project and commissioned the machine in the spring of 2023.
This machine’s housing is a special version of the standard model with two enlarged openings in the discharge area, which allow for faster discharge of both crushed material and air. A downward-facing flanged motor was installed to provide more space for operation on the platform. The functionality of the RPM 1113 allows significantly higher throughput while consuming less energy compared to the rod mill.
Benedikt Weber, who is responsible for building materials machinery sales in the region, highlights that alternating right and left operation of the machine maximizes the utilization of the components used in this series.
He said: ‘In terms of efficiency, the cost-benefit ratio of the rotor impact mill far surpasses that of a rod mill. It offers a very high degree of crushing and delivers excellent cubic sand with a high proportion of fines and round corners.’
Consequently, the mill is predominantly used to produce sand for the concrete, asphalt, and dry mortar industries.
BHS-Sonthofen also provided the complete control system for the two rotor impact mills, customized specifically for Dachser’s needs. This includes powerful frequency converters for energy-efficient operation of the machines and a state-of-the-art user interface featuring touch screens.
‘Despite different feed materials, both machines deliver identical, high-quality crushed sand, something that is particularly sought after,’ said Mr Zacher, summarizing the advantages of the two plants. ‘Having both the plant and control system from a single source has streamlined installation and daily operations significantly.’
