In order to increase the throughput of the sometimes extremely fine cement at Ohorongo Cement (PTY) Ltd., BEUMER Group supplied and installed filling, palletising and packaging technology for a third complete line from a single source.
Ohorongo Cement (PTY) Ltd, a member of Schwenk Zement KG, is the only cement manufacturer in Namibia. Its mission: to meet the national demand for cement. To increase the throughput of the cement, some of which is extremely fine, BEUMER Group supplied and installed a third line completely from a single source - and within a tight time frame.
There is nothing here, almost nothing. The nearest small town is Otavi, 20 kilometres away, with Tsumeb to the north. With a population of around 19,000, it's not exactly a big city either. In between, a lonely road runs through the vast plains. And right here, in the limestone-rich Otjozondjupa region in Namibia, Schwenk Zement has built a plant here. The operator is Ohorongo Cement, or simply Ohorongo. The 1001TP3 subsidiary produces two types of Portland cement including a very fine quality. „Our building materials are particularly high quality,“ emphasises plant manager Manfred Pirker.
Choosing the right partner
Once the cement has been produced, it is ground. It then comes here either directly onto the lorry as loose material, in big bags or it is filled into sacks. „We use 50-kilo bags in this plant,“ explains Pirker. „After filling, they are stacked on pallets and covered with stretch film.“ The plant previously used two packaging lines for this purpose, for which BEUMER Group supplied and installed a high-performance paletpac layer palletiser and packaging machines from the stretch hood series years ago. „In the long term, however, we could no longer meet the growing demand for cement,“ says Pirker. „We absolutely had to increase our throughput.“
Ohorongo had gained very good experience with the two existing packaging lines. It was therefore clear to those responsible that only BEUMER Group could be considered as a partner for the delivery and assembly of the third complete line. The parent company Schwenk has also successfully relied on the sustainable solutions of the full-range supplier of filling, palletising and packaging technology for years, as well as on pipe conveyors such as those in the cement plant in Bernburg near Magdeburg. There, the closed conveyor system transports alternative fuels such as shredded plastic material, textiles and paper from the storage hall to the furnace feed systems. „Over the years, we have also been impressed by the Smooth service and the On-site support“, reports Pirker.
Bottled: not too much, not too little
„Among other things, we had to take into account the climatic conditions, that prevail there,“ explains Holger Schneider, Senior Sales Engineer at BEUMER Group. Temperatures in the desert regions can reach up to 40 degrees and more during the day in midsummer. „This can affect both the Flow behaviour of the cement as well as to the Stretchability of the stretch films have an impact,“ he explains. The machines had to be designed accordingly. The engineers also had to adapt the technology to the newly constructed extension to the existing packaging hall.
As the cement produced here is particularly fine, BEUMER Group installed a nFilling system operating according to the air filling principle of the BEUMER fillpac type with eight rotating filling spouts. The Product filling takes place according to the gross systemThe bags are weighed during the filling process. For this purpose, the BEUMER fillpac is equipped with a calibratable weighing equipment equipped. The weighing electronics ensure that the system always achieves an exact filling level of the bags. Special software enables the weight between the filling spout and the scales to be permanently synchronised.
High efficiency of the filling line
The cement enters the filling vessel via a rotary flap. Uniform product discharge is made possible by the separately adjustable boiler bottom and top ventilation. This ensures a Continuous product flow with minimum compressed air consumption. During filling, the filling nozzle with venting channel and a cyclically operating ejector sucks the air out of the bag. The filling nozzle is blown free after each filling process. This prevents contamination of the filled bag. „This allows the conveying air volumes to be set separately depending on the product,“ says Schneider. The filling turbine is characterised by Speed and maximum material throughput from.
In order to further increase the efficiency of the filling system, BEUMER Group is also adding a Bag opener with bag bundle magazine the latest technology. Servomotors automatically drive the drive bar and the suction gripper in a precise and energy-efficient manner. The gripper and attachment system securely pushes the bags from the stack onto the filling spout. In this way, 2,400 bags per hour can be pushed on with high precision.
Gentle palletising ensured
To clean the bags afterwards Fully automatic, reliable and above all fast to palletise, BEUMER Group installed a BEUMER paletpac 3000 layer palletiser, which stacks the 50-kilo bags precisely layer by layer onto the pallets in a five-layer formation. „In order to turn the bags quickly, gently and dimensionally stable into the required position, the systems are designed with a double-belt turning device,“ explains Schneider. „In terms of positioning accuracy, this offers a huge advantage over conventional turning methods.“ This is because the system component moves the bags without mechanically deforming them. Instead, two parallel-driven belt conveyors are used, which travel at different speeds and thus turn the bags quickly and gently. The intelligent control of the double-belt turning device takes into account the dimensions and weight of the bags in order to achieve exact positioning as specified by the respective packing pattern.
Packed quickly and securely
The finished bag stacks are transported to the packaging system via roller conveyors. For this purpose, the full-service provider supplied the BEUMER stretch hood A. „We have redesigned this machine from the stretch hood series from the ground up,“ explains Schneider. Compared to the other systems, the user can handle it even more easily and safely. To make work easier for the maintenance personnel and thus also ensure greater availability of the system, the Packaging system completely without platform out. Maintenance work such as changing blades or welding bars is carried out at floor level. Another advantage is the compact design and the associated low installation height and footprint. „This means that the BEUMER stretch hood A fits very well into the new hall,“ says Pirker.
A film transport system that is gentle on the material Previously cut and welded film bonnet of the system. The weld seam of the film bonnet cools down on the way to the reefing and stretching unit, so that this reefed without loss of time can be used. This means that neither an energy-intensive cooling unit nor efficiency-reducing cooling times are required. The pallets are thus stored with a faster clocking packed. „We process 60 pallets per hour,“ says a delighted Holger Schneider from Ohorongo: „This can be increased even further if required.“
A hot affair
However, there was still something to consider when it came to packaging: „Unlike in Germany, in Africa the goods don't just travel a few hundred kilometres on the lorry loading areas, but often up to 1,000,“ reports Pirker. Added to this are the high temperatures, which soften the film material. „In order to achieve the necessary safety, we use films with a thickness of 80 and 100 micrometres,“ he adds.
„A packaging line has been created here that is specially tailored to our requirements.“ Plant manager Manfred Pirker was visibly satisfied at the commissioning.
This was only possible within a tight time frame because everyone involved in the project worked together intensively. The cement manufacturer was impressed by the sophisticated technical planning, the rapid development and optimum customisation of the systems and the very fast implementation by BEUMER Group.
