Moisture-sensitive powder batter mixes, such as those used to make crisps and other savoury snacks, require a high degree of homogeneity combined with precisely controlled and extremely stable moisture levels. According to Lödige Process Technology, its continuously operating Type CM CoriMix Ringlayer Mixer is the ideal solution for this demanding process engineering task. The machine must also comply with all current hygiene and ATEX specifications.

Powdered batters for crisps, for example, consist of potato powder and other powdered ingredients. Water is then added to the dry premix. This process step is decisive for the quality of the end product. As only when the defined degree of moisture of the batter mix is guaranteed precisely and continuously, it can be deep-fried or baked perfectly and with a stable shape. The special challenge here, according to Lödige, is that the "return material," which is produced when the crips are cut out, is also continuously fed into the mixer. The task of the Type CM CoriMix is to ensure a consistently homogeneous mixture of powder, water and recycled material in continuous operation.

Ringlayer process

Excellent distribution of liquids at high throughput rates and high homogeneity is required for powder batter mixtures. Lödige states that the ringlayer process is ideal for this due to its characteristic strengths. In terms of cost effectiveness and versatility, the use of Ringlayer Mixers is also an attractive option in numerous industries.

Unlike other mixer types, the mixing unit of a ringlayer system rotates at high circumferential speeds. This accelerates the added product components centrifugally. The result is the formation of a ring layer. Within this concentric layer, there are enormous speed differences between the rapidly rotating mixing tools and the stationary mixing wall. This means there is particularly high level of friction in the profile of the ring layer. The application-specific shaped tools of the mixing unit move the product through the mixing chamber throughout the process, similar to a plug flow. As this process takes place extremely quickly, the residence times are very short. For powder batter mixes, for example, they are only about 50 to 60 seconds; for other applications even less.

Lödiges Ringlayer Mixer that has been tried and tested for years. The Type CM CoriMix offers low space requirements, easy handling and maintenance, great cleaning options and durability were the focus during its development. A temperature-controlled heating/cooling jacket enables fine tuning of the process parameters and ensures constant conditions even at 500 to 1000 rpm (revolutions/minute) and corresponding friction energy.

The mixing drum is divided in the middle along its entire length and can thus be opened. This means that the mixing system can be conveniently cleaned, easily maintained and, if necessary, simply adapted to new requirements. With this and other design details, the machine also fulfils all current requirements with regard to hygiene and an ATEX-compliant design.