Packaging
Baby Food: the right formula Infant Formula line increases capacity, flexibility, traceability and quality.
Wednesday 20. April 2011 - ?The Challenge The Hochdorf group is one of the leading foodstuff companies in Switzerland with three production sites. Made from natural ingredients such as milk and wheat germ, Hochdorf products have been contributing to consumer's health and wellbeing since 1895 - from babies to senior citizens. In their plant in Sulgen, near the Bodensee, Hochdorf Nutritec decided to increase the production capacity of Infant Formula and standard milk powders.
High quality and hygienic standards and effective process flow with perfect traceability were the main requirements. The very many different recipes made a quick, flexible and safe change-over without cross contamination necessary. Ergonomics was another key area.
??The Solution
Tetra Guerin offered an ambitious global, full turnkey solution divided into 2 main parts:
1) Before the dryer: raw material handling and storage to accurate feeding of Tetra Almix vacuum mixer. Raw materials in bulk are transferred through 1 truck reception station. Due to long distance between truck and silos (25m), and even though the trucks are all equipped with their own blower, we provide an additional blower with its own air treatment. Truck unloading time is about 1h.The storage of raw material is made into 3 indoor stainless steel silos: 2 of 80 m3 each for lactose and dextrose and 1 of 30 m3 for premix. These silos are all fully explosion risk protected, equipped with continuous level indicator, dry air blown, and fixed on concrete first floor. Premix silo is fed by existing pneumatic transfer, the 2 others by truck reception station. Silo extraction and product dosing is done by vibrating bottom and screw feeder into 2x5000L weighing hoppers (accuracy +/- 2kg) for lactose and dextrose and 1x2000L weighing hopper (accuracy +/- 1kg) for premix. For cleaning and production flexibility, lactose, dextrose and premix silos can be fully emptied into big bags. For this, we provide 1 big bag filling station with capacity of 6 big bags per hour minimum (see photo). Once dosed and weighed; the raw materials are fed into a Tetra Almix vacuum mixer with an output of 5000kg/h (2 batches of 2500kg per hour).
2) From dryer output: dense phase pressure pneumatic transport to either intermediate silo storage for standard milk powder or direct feeding to Baby Food milk powder inert gas big bag filler. The dryer produces either skimmed milk powder for truck filling and silo storage, or Baby Food milk powder into big bag filler with different mixed and/or premix products. Start/stop product for Baby Food: at beginning and end of production phase, product out of specs (rework) is diverted from the normal route to a 5m3 hopper. This hopper is used as a buffer either to reintroduce rework at inlet point of fluid bed below dryer, or to feed big bags. Dryer output solution: to comply with Baby Food very high quality specs, a pressure dense phase pneumatic transport system is used to transfer product from dryer to storage silos. This “gentle transport” allows minimizing breakage by combining a very low speed (between 3 to 6m/s) with high concentration of product into the transport pipe (between 40 to 50kg of product per kilo of air). Due to layout constraints, single pot pulse conveyor has been selected. The flow rate is tuned according to dryer output and product characteristics.
For skimmed milk, this pneumatic transport system feeds 2 indoor stainless steel silos of 130m3 each, fully explosion risk protected, and equipped with continuous level indicator and air drying system. Handling from intermediate silos: extraction from silos by vibrating bottom and screw conveyor dosing device to feed surge hopper. A rotary valve regulates product feeding into pneumatic transport. Skimmed milk powder transfer to truck fill in station: a 20T/h diluted phase pressure pneumatic transport is used to transfer product from silos to truck filling station. Extraction flow is regulated by rotary valve above adjustable truck filling device equipped with cyclone de-dusting station. Truck filling time is about 1h. The same pneumatic transport is used to feed 3 existing silos. Due to additional air volume, we supply new filtration system.
For Baby Food, the pneumatic transport system below dryer feeds an intermediate 6000L buffer hopper above inert gazing big bag filling station. For “gentle dosing” and hygienic purpose, the extraction of product from this buffer hopper is made by vibrating bottom and vibrating conveyor into 2000L inert gas hopper. This hopper is equipped with continuous control of remaining oxygen level (max. 2%) and feeds big bag filling station with a capacity of 5T/h.
Anticipating the future, a more productive and flexible way of handling the ingredients was also proposed, using big bags, truck and can filling machines. Furthermore the offer includes the dry ingredient handling for every powder in the plant, with full traceability from raw material to finished product. The equipment is designed to meet the highest quality and hygienic standards taking an ergonomic and safe working area into account.
?The Result
The new plant has different hygienic level and dedicated rooms for raw material silo storage, skimmed milk silo storage, pneumatic transfer, and Baby Food milk powder filler. The Guerin process and equipment ensure that all raw materials are free of foreign bodies, lumps or metallic particles. Increased production capacity and full traceability are achieved with high quality and hygienic standards.