Gentle Dispersing...

Is - unfortunately - not possible

This processing step by definition requires a high energy input, as the requirement of a dispersing step in most cases is a particle size reduction of a disperse phase into a continuous phase. The range of the size of particles in a process is close to or below 1 µ, and a conventional mixer can’t cope with this requirement and therefor will not be used.

For example, the physical impact of a sugar crystal is not possible with a propeller mixer, while large lumps can be reduced in size because of the impact of the propeller on the lump.

For this reason different dimensions of mixing tools are required in different processing steps. When applying dispersing energy this is restricted to a small volume only, thus increasing the density of the energy.

Convenient machines are the rotor-stator-dispersing machines that offer the treatment of a wide range of dispersing and emulsifying processes. Different to other principles (ultra sonic, nozzles or high pressure homogenisers) these are self pumping, provide CIP cleaning and are much less expensive and require only a small installation space.

Dispersing machines are available as batch or as Inline machines.

Batch dispersing machines are being used in vessels up to a limited size where solid particles have to be reduced and/or emulsions are processed. Without an additional stirring element the maximum volume that can be handled is about 3-4 tonnes, having in mind that the rheology and the viscosity do not exceed a certain limit.

Typical examples are the fast dissolving of small pearls or pellet type solid components into liquids, or the particle size reduction of natural products as a first step for the following extraction or the emulsifying step when producing low to medium viscosity creams, pastes or sauces in different volumes.

These machines are limited when treating medium to high viscosity products as the pumping and mixing capability becomes limited or restricted. By virtue of their construction these machines do not have a special pumping or conveying element.

A very good example for a batch dispersing process is the dissolving of flavour crystals in solvents, dissolving of resin and waxes or solid caramels in a minimum basic liquid volume.