In the production process of some food or pharma products the process step “dry grinding” is at the end of the value chain. Because of that it is not possible to conduct a sterilisation process afterwards. A mill must be wet cleaned at certain period to remove deposits and comply with the microbiological specification of the final product. Therefore, it is mandatory that the plant execution and the construction is focused on the inner accessibility to avoid dead spaces, where product deposits can accumulate. All relevant areas must be accessible during wet cleaning. All these conditions apply to lactose grinding: Lactose in dry quality is the last process step after a long, wet process and requires – as a high-end microbiological quality product – a special process design (see Photo).
Market forecast for lactose
Lactose is used in the food and pharmaceutical industry: The global market value for lactose with permeate powder is valued at more than US$2.0 billion in 2017 and is expected to reach US$2.4 billion in 2022, implying a compounded annual growth rate of 3 percent over the forecast period at constant prices.1
Lactose processing at Hosokawa Alpine
After the lactose is obtained from the wet process, it is dried on a spray dryer or fluid bed dryer. The resulting lactose must be ground for further processing to meet the special requirements of the food and pharmaceutical industry regarding the particle size distribution. Hosokawa Alpine offers many years of experience in lactose processing, especially in ultra-fine grinding (see Figure 1). The worldwide installed basis represents the conviction and trust in the ALPINE know-how. The fundamental principle of the process is to disintegrate and mill the dried lactose to a uniform powder for an easy and flexible application. Pending on the raw material, customer requirement and end use, the type of mills vary from fine impact mill to classifier mill to air jet mills.
Lactose powders with a precise top cut and a steep particle size distribution for special requirements are processed by the combination of high-precision classifier technology and an ultra-fine grinding mill. The classifier mill reaches particle sizes below 75?m (200 mesh product) because of high rotational speeds and an integrated classifier wheel. Sucked from the airflow, particles migrate from the milling chamber to the classifier wheel. The wheel rejects the coarse particles back to the milling elements until they are fine enough to pass it. A high airflow rate combined with conditioned air guarantees a cool production process for gentle milling and good product qualities at comparably lower operation costs.
New Dairy design for Air Classifier Mill ACM
Together with our customers we have redesigned the air classifier mill ACM for the special needs of the dairy industry: NEW Dairy design (see Figure 2). This includes a hygienic design for machine, sealing and bolting. Dead spaces in conventional systems can lead to product deposits and lead to microbiological problems. A monobloc construction with Ra < 0.8 finishing of the mill ensures that there are no dead spaces behind the grinding track or air guide ring. By construction expertise there are no inner horizontal layers, where water can accumulate and support bacterial growth. This is an advantage from the microbiological side to guarantee a high product quality. Since there are cleaning nozzles and drainage integrated in the machine at different places, cleaning is possible ideally without removing individual components. This leads to a reduction of cleaning cycles in comparison to conventional machines and the machine is effectively a longer time for production available.
12 grinding systems in the last 5 years – the awareness for hygiene increases
By changing the following parameter: speed of rotor, speed of classifier and air volume flow the mill enables fast product changes and adaption to changing markets and customer requirements. Various machine sizes allow high throughputs and a profitable investment.
In the last 5 years, 12 grinding systems which meet the high market demands were delivered by HOSOKAWA ALPINE for lactose applications. As conclusion the awareness for hygiene in the food processing industry is an increasing demand and no longer only a request from the dairy industry.
1) https://www.foodingredientsfirst.com/news/whey-andlactose- analysis-markets-on-growth-track- protein-trendremains- key.html