What advantages does a hollow-sphere mixer offer for sensitive, fragile agglomerates in the food sector?
A hollow-sphere mixer is advantageous where protecting the product matters more than a high mixing intensity. Its essential benefit lies in the comparatively gentle restratification of the mix and in the geometrically smooth vessel shape with little dead space.
Mixing efficiency depends strongly on the specific design of the mixing tool. A modified anchor agitator is inexpensive but less efficient than an evenly formed helical mixing tool. Helical mixing tools with a consistently uniform helix pitch permit more even product restratification and a considerably gentler action.
Gentle mixing action
The spherical geometry of the vessel reduces corners, edges and local stagnation zones. This lowers the risk of particle breakage, abrasion and compaction. It is particularly relevant for spray-dried powders, instant agglomerates, encapsulated ingredients or other fragile structures.
The mixing action is predominantly based on gravity and restratification and is therefore considerably less aggressive than with intensive tools of high shear action. This is an advantage for sensitive products, provided the required homogeneity is still reliably achieved with this mild mixing intensity.
Suitable for sensitive products
Hollow-sphere mixers can be useful for products that have to retain their structure, for example:
- spray-dried food powders,
- sensitive instant agglomerates,
- vitaminised or functionalised dry blends as well as products with coated particles or coatings.
The advantage here lies less in maximum mixing performance than in preserving the particle structure and the sensory or technological function of the product.
Discharge and hygiene
A smooth vessel geometry can make discharge easier and reduce product build-up. This is significant in particular for applications in the food sector, since product losses, carry-over and cleaning effort can be lowered in this way.
In hygienically sensitive applications, however, alongside the vessel shape the design of shaft seals, the discharge, the bearing arrangement and the cleanability of the entire system are also decisive. A good hollow-sphere mixer must therefore always be assessed as an overall concept.
The amixon® SpherHelics® hollow-sphere mixer for fragile agglomerates
The amixon® SpherHelics® hollow-sphere mixer blends fragile food agglomerates gently and yet with high precision. A special helix geometry replaces thrust-intensive anchor agitators and thereby protects particle structure, solubility and freedom from dust.
Gentle helix instead of thrust and throw effects
- A rotating mixing tool blends the product three-dimensionally.
- The best mixing action arises with an inclined axis of rotation.
- This creates uniform flows and short mixing times.
- Many competitors use modified anchor agitators as an obliquely installed ring.
- These anchor agitators require a great deal of thrust energy and compact the mix.
- amixon® helices instead have a defined pitch.
- They generate gentle flows without dead spaces.
- The result is ideal mixing quality with minimal energy input.
- Particle structure, solubility and freedom from dust are preserved.
Highest precision despite gentleness
- Even at component ratios of up to 1:100,000, an ideal distribution is achieved.
- This ideal distribution cannot be improved further in practice.
- This applies irrespective of the fill level.
- Micro-components such as vitamins, trace elements, flavourings or functional additives are distributed precisely.
- Spray-dried agglomerates do not break up in the process.
Flexibility for different product states
- The hollow-sphere mixer also blends moist and pasty materials.
- Liquids can also be incorporated in a targeted manner.
- Liquid lances can be positioned for the wetting of powders.
- Optional cutting rotors generate shear and impact effects where required.
- They break up agglomerates in a targeted manner, for example during moistening or coating.
- For sensitive products this option can be switched off.
- The SpherHelics® from amixon® therefore works either gently or with deagglomeration.
The spherical shape as a cleaning advantage
- For the same volume, the sphere has the smallest surface area of all rotationally symmetrical vessels.
- This can make cleaning easier.
- Only a KoneSlid® mixer can discharge completely in a gentler manner.
Excellent, dead-space-free residual discharge
- On request, the ComDisc® tool provides excellent residual discharge.
- The discharge fitting sits at the bottom in the form of a spherical segment.
- Only in this way is dead-space-free mixing possible.
Discharge without destruction of structure
- Some hollow-sphere mixers consist of two hemispheres that fold open.
- Others have circular inspection doors.
- The KoneSlid® mixer from amixon® has one or two inspection doors, of oval design with OmgaSeal® sealing. This saves space and is particularly ergonomic.
- On request, wet cleaning is carried out fully automatically with the WaterDragon® system.
- Cleaning can be performed dry or wet.
- The amixon® mixing tool is smooth, hygienic and readily accessible.
Energy efficiency and preservation of particles
- Drive power and energy consumption are low with the SpherHelics®.
- Low energy input means low mechanical stress.
- Low mechanical stress preserves the agglomerate structure.
- amixon® avoids unnecessarily high rotational speeds through the efficient helix geometry.
- amixon® avoids mirror-symmetrical twin mixing tools on account of better mixing quality and cleanability.
- On request, SpherHelics® and KoneSlid® meet the EHEDG guidelines, the FDA hygiene guidelines and the 3-A Sanitary Standards; large Clever-Cut® inspection doors with OmgaSeal® sealing make cleaning and inspection ergonomic and safe. The mixing chamber is designed for ATEX Zone 20. On request, a vacuum can be applied during mixing and the mix inerted, for a longer shelf life of oxidation-sensitive instant products.
- Which design is right for the specific agglomerate is clarified by amixon® in mixing trials with the original product, including assessment of breakage rates and mixing quality, in the company's own pilot plants in Germany, Japan, India, Thailand, China, South Korea and the USA.