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MDA Technologies 3/2014

MDA Technologies 3/2014

Drive

Drive Technologies xxx 02 Ekato constructs the perfect agitator for each product Production mixer design Toothpaste production systems basically consist of an evacuable vessel with an agitator, a homogenizer, and various dispensing systems for the introduction of ingredients into the process. Liquid ingredients are either measured and then vacuum-inserted into the vessel or dispensed by gravimetric methods. Powders and thickeners to increase viscosity can be added via the integrated homogenizer or drawn into the vessel through a valve at its base. Complex calculations for the scale-up For larger mixer dimensions, Ekato had to determine the components’ dosage and dispersion times, blend and homogenization times, vacuum values, and the necessary agitator and homogenizer performances. The agitator and homogenizer were configured according to the mixing performance equation for mixing technology: P = Ne . ρ . n3 . d5 for turbulent flow or P = Ne . ρ . n2 . d3 . η for laminar flow. Based on its extensive experience, Ekato determines the power coefficient “Ne” (or Newton number) for each respective impeller and the product’s specific viscosity curve. In addition to the product concentration ρ, the equation furthermore contains the speed and the diameter – with the exponents 2, 3, or even 5, these values are especially important. That is why the correct configuration of the agitator and homogenizer drives is crucial. The drive supplier Nord was required to configure motors and gear units with the performance according to Ekato’s calculations, and to make them as efficient and durable as possible. Since the agitator drive is installed on top of the production mixer, it should be as compact as possible despite the high performance required. Agitator drives as large as a city car This application, which depends on homogeneous product quality, calls for speed and continuity. The radial and axial loads on the agitator shaft, which are very high due to the high product viscosity, must be taken into account for the drive configuration. Nord Drivesystems configured and supplied two 250 kW motors with industrial gear units which provide nominal output torques of 242,000 Nm. Nord is the only manufacturer worldwide to produce such extremely large industrial gear units in this power range in the proven one-piece Unicase housing. Hence, the type SK 15407 3-stage helical bevel gear units, though of an impressive size, are still relatively compact as the Unicase design allows for larger rolling bearings which can accommodate higher forces. Conclusion At 10,000 liters effective volume each, the two new production mixers produce a maximum of 12,000 to 16,000 kg toothpaste per batch, depending on the product concentration. The output volumes range between 36 MDA Technologies 3/2014

ubrizierungsebebe 2 I rubrizierungsebene 03 The geared motors from Nord Drivesystems meet the standard set by the record-sized plant Industrial gear unit in a Unicase housing Currently available in eight sizes in Unicase housings, Nord Drivesystems’ powerful industrial gear units cover smaller frames for torques from 25,000 Nm to large models up to 242,000 Nm. In this series, a single standard housing per frame size spans the entire transmission range. A highly flexible and modular concept provides countless options for straightforward and fast configuration for individual models. If required, Nord assembles complete drive trains for users, including swing bases with gear units and motors as well as options such as drum brakes, fluid clutches, fans, and auxiliary drives. Even the largest industrial gear units are manufactured to Nord’s one-piece Unicase concept: all bearing seats and sealing surfaces are machined in a single stage on state-of-the-art CNC machining centers. The benefits include extremely high reliability and exceptional sealing with safe handling of even the largest torques; combined with high axial and radial load bearing, quiet running, low maintenance and an exceptionally long operating life. 6,000 and 11,000 kg per hour. Compared to the 2,000 to 3,000 liters of the previously largest plant, that means a three or fourfold increase of the production rate. Thus, the end users’ target was not only realized but also surpassed. An additional advantage is that the compact design enables an optimal utilization of production space. The drive systems have to meet the same requirements as the mixing technology: they must provide high reliability without requiring maintenance. Company name: Nord Drivessytems Headquarters: Bargteheide, Germany Turnover: approx. €450 m (Nord-Group) Employees: more than 3000 worldwide Products: Geared motors, industrial gear units, motors, frequency inverters, motor starters Photographs: lead fotolia, others Ekato and Nord www.nord.com About MDA Technologies 3/2014 37

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