Maschinenfabrik Gustav Eirich – a leading German manufacturer of mixing equipment, claims that its technology is way ahead of the competition – and recent independent studies confirm this fact.

“For the first time, a neutral study of ‘simple mixers’ in comparison with an Eirich mixer was commissioned from the ‘Institut fur Fertigteiltechnik and Fertigbau Weimar’ (Weimar Institute for Finished Part Technology and Finished Construction),” says a spokesman for the company, which has completed a century in the sector.
Concrete specimens were taken from a leading German manufacturer of finished concrete products for road, garden and landscape design who works with various types of mixers at several locations in Germany.
In its report published last year titled “Studies of mixing qualities of facing concrete mixers”, the institute made the following comments: “The Eirich mixer is outstanding for its very short mixing times. Subject to the same mixing drum contents and conditions a comparable mixed product is achieved with the Eirich intensive mixer faster than in the case mixer “X” and as a consequence brings economical advantages.
 “Moreover, the high uniform consistency of the concrete prepared with the Eirich mixer was obvious. The apparent specific gravity of the fresh concrete determined on five specimens, fluctuated in the case of the Eirich mixer by 0.19 per cent, but with a planet mixer by 0.46 per cent. The findings were similar for water and solid matter content and in the case of the resistance to frost and salt,” the report concluded.
A more consistent quality of concrete was given with Eirich mixer in a considerably shorter mixing time than with mixer ‘X’.
“In practice this means: each mix is like the next with less waste through surface faults. An investment in Eirich mixing technology pays for itself in a very short time. Less wastage.
“What many Eirich customers have known for very many years was supported by this study,” says the spokesman.

The Eirich advantage
Over the past century, Eirich has demonstrated its inventiveness with a number of patents and new developments, including the Eirich intensive mixer which replaced the ring trough and planet mixers.  The clearly higher standards of this type of mixer led to the breakthrough into international markets and a spread in the fields of application.
 “The actual difference between Eirich mixers and all the other mixing systems throughout the world is to be found in the unique Eirich mixing principle: turning mixing container and transportation of the mixed material; and the variable slow to fast running mixing tools for mixing,” says the spokesman.
He continues: “This principle has the following effect: Separating the transportation of the mixed product and the actual mixing operation makes it possible to vary the speed of the mixing tool (and as a consequence the energy introduced in the course of the mixing operation) over a very wide range.
“Eirich mixing technology – unlike all other mixing systems on the market – allows the tool speed to be adjusted optimally to the respective product. The Eirich mixer mixes at peripheral speeds between 2 m/sec and 40 m/sec.
“According to the ideal mixer theory, the energy which is introduced by a mixing tool in the mixture increases by a potential one-third of the peripheral speed. This makes it understandable why Eirich mixers are in demand today for all applications where difficult mixing tasks have to be faced and quality is demanded.
“In the concrete sector, this applies to the mixing of roof tile concrete, facing concrete, railway sleeper concrete, light concrete, foam concrete, self-compacting concrete, fibre concrete, heavy-duty concrete, ultra heavy-duty concrete or polymer concrete, for example.
“Apart from the simple mixing of sand with gypsum or cement and lime, the Eirich mixer can also be used for applications that call for mixing colour pigments and light materials, such as polystyrene and drying additives of all kinds to provide an absolutely homogenous product. The mixing process is of great significance as far as such mixes are concerned, as they require the perfect distribution of the smallest quantities of additives (which are often added in ppm range quantities) in addition to the optimal opening up of fibres.”
Eirich’s range of intensive mixers can be equipped with an automatic, pneumatic inner cleaning system. This is particularly important when fast changeover to another recipe is required, for example, when mixing colour pigments under the mix and changing from grey to white cement.
In recent years, Eirich has become the research and development partner for universities and technical colleges wanting to do more than just “mix concrete”. As a consequence Eirich mixers have been made available to a number of German, Belgian and Dutch universities. When mixing there were degrees of freedom given which any other mixing system could not offer.
“A universal mixing unit that can fulfil any feasible mixing task in the concrete industry and process all possible consistencies can be the solution to the trend towards ever increasing high-quality concretes:

• The mixing tool can run fast or slow;
• At high tool speed
   * fibres are optimally mixed;
   * pigments completely fractionised; and
   *  fine particles (for example in the case of fine grain concrete) are mixed optimally.
• Mixes with high mixing quality are achieved at medium tool speeds;
• Light additives or foams are carefully mixed under the concrete at low tool speeds.
  The experience gained in practice has confirmed that:
• Concretes of any type and consistency, even SSC and UHPC, can be produced quickly and with a high quality;
• The quantities of cement and pigments can be reduced (a result of better distribution);
• Improvement in quality compared with earlier mixing systems;
• Waste, more especially as a result of poor face surfaces, is clearly reduced; and
• The investment is amortised in a very short time.

Today, a speciality is the preparation of ultra high heavy-duty concrete in the Eirich vacuum mixer. Air inclusions, which have a detrimental effect on the strength of concrete, can be avoided to the greatest extent.
He continues: “Increasing demands are being made in all branches of industry and the standards set by customers for quality concrete and surface finishes for paving stones are ever increasing. How does one now produce perfect surface paving stones? There is an easy answer by using an adequately good mixer.
“Quality starts with the mixing process. All subsequent measures taken are no longer able to eliminate the faults caused by inadequate mixes. For many decades now, many concrete product manufacturers have been saying that better pigment mixing and absolutely homogeneous concrete can only be achieved with the Eirich mixer.
The low number of tools required as well as their constructive design and the use of special materials ensure low expenditure for service and maintenance. Primary wear parts can be easy replaced, thanks to the size of the different parts and easy fastening methods. It has been possible to improve the service life of wear parts to a considerable extent by developing special mixing tools on the basis of modern materials. Eirich delivers turnkey dry mortar plants including the steel construction work and the silo, dosing, weighing and conveying technology and sand drying and sifting facilities. Bagging, palleting and foil plants are planned and incorporated in the project.
The plants are generally controlled by means of a Siemens family SPC S7 and incorporate the Eirich EDS dosing control system and a PC-supported visualisation and operating system.
The PC-based and Eirich-MIC-NT multi-station control system has been developed more especially for use in complex dry mortar plants (for example, in the case of several mixer lines). This system incorporates:

• The Oracle high performance data base system for up to 10,000 different recipes;
• Operation of the plant sequences for up to eight mixer lines;
• Registration of operation, production and quality data;
• Order, stock and warehouse administration;
• Extensive possibilities of balancing out mixes through freely definable filter functions; and
• Data exchange with ERP system at the customers.

Established in 1863 as a mill workshop, today Eirich has spread its operations in several countries across the globe. The first “Eirich mixer” was built in 1924, which today is now in its fifth generation and is working in more than 300 branches of industry but is also used of course, for mixing concrete.
The current range of plants and machines supplied cover the entire sector and extends from the laboratory size machines to 7000-litre mixers for production and to protect the environment.
“Today, the company’s systematic internationalisation is reflected in six factories spread on three continents – in Germany, the US, Brazil, Japan, India and South Africa. Further expansion in Asia and more especially in China is well on its way.
Eicher’s range of mixers, which start from the 750 l, extend up to 1500 l, 3000 l and the 7000 l capacities. Mixers in the sizes of R15 and R24 are also working in the dry mortar and limestone sand branches as well as for the preparation of concrete (for example, facing concrete, roof tile concrete, SVB and railway sleeper concrete).
“For more than 14 decades, customers have held Eirich in high esteem as a reliable innovative partner, which in turn, is both a challenge and commitment for us in the future,” he concludes.