#A liquid with high viscosity manual

Some companies produce mixers with completely and easily removable agitators, allowing a high speed product changeover: use of a flat-flange clamshell coupling will allow operators to raise the agitator out of the mixer/blender without moving the end shafts, bearings or seals this feature adds cost to the machinery purchase, but can save hours between batches, so it is paramount for plants preparing batches with e.g. A flush plug discharge valve also reduces stagnant areas in the trough and simplifies cleaning. A well designed mixer/blender/agitator has no “dead zones” where residues can accumulate, and the interior stainless-steel surfaces must be well-polished, welds included optional end-plate scrapers may be used for materials that tend to cake or pack. This difficulties can endanger not only microbiological safety but also allergen safety between batches containing different ingredients (cross-contamination risk).

#A liquid with high viscosity manual

High viscosity fluids or pastes, however, firmly sticks to walls and agitators, making it difficult to remove thoroughly all residues often a manual intervention using brush, steam, compressed air and/or high pressure water spray is needed. Many mixers/blenders have CIP (cleaning in place) systems that easily remove all food residues. Some more problems arise after production is finished and it is cleaning time. Viscosimeters are used to control this parameter (3). for batters and coatings, thickness is important to ensure success of coating process (on meat, fish, vegetables and so on) and furthermore to ensure coating remains on the product after cooking. Figure 1: Example of a weight belt feeder system for the production of snack bars (K-Tron process group)įinal product viscosity is an important parameter: e.g. Helical blades allow double planetary mixers to handle viscosities as high as 8 million cP (centipoise) (2). As viscosity rises, however, even a multi-shaft mixer arrangement will eventually fail to produce sufficient flow: the logical solution is to utilize agitators that move through the batch regardless of product flow this is what planetary mixers and sigma blade mixers (kneader extruders) do: in a planetary mixer, two or more blades rotate on their own axes as they orbit on a common axis the agitators continually advance into the batch and contact fresh product all the time.

For products that undergo a high viscosity phase, multi-agitator and planetary mixing equipment are commonly employed. High solid formulations of medium viscosity can be prepared in single-shaft rotor/stator mixers or high speed dispersers. Some mixers consist of a U-shaped horizontal trough and an agitator made up of inner and outer helical ribbons that are pitched to move material axially, in opposing directions, and also radially: this combination promotes fast and thorough blending, with speeds in the range of 300 feet/min (1).

Internal mixing parts can be shovels, helixes or turbine for medium-viscosity foods for high-viscosity application, the internal organ will have high resilience, high diameter in all its parts an low rotation speed.

Machinery used for these applications can have a fixed body with moving internal mixer/blender/agitator, or both body and internal parts moving, usually in opposite rotary directions, in order to enhance the mixing effect. Mixing high viscosity fluids and high solids formulationsĮxamples of viscous liquids or high solids formulations are chocolate during tempering, nougat, confectionery bases, many bakery doughs, batters, pasta before extrusion, meat pâté, fats, etc.

In these circumstances, having the right machinery is just a part of the picture: a deep knowledge or all ingredients is needed in order to decide the mixing equipment, length, temperature etc. Bakery and confectionery industries, among others, face the challenge of mixing high viscosity fluids (fats, syrups, etc.), mixing fluids containing high volumes of powders (pastes, doughs, covering batters etc.) or mixing together in the same recipe solids of different size, shape and density (ingredients for snack bars as cereal flakes, nuts, dried fruit, chocolate bits etc.).