Silverson Machines manufacture the largest capacity range of a single manufacturer, with mixers available for processing batches as small as 1ml, to mixers able to process 30,000 litres. Throughout the product range, each Silverson mixer is engineered to the same fine tolerances with the high shear action being generated by the rotor and stator workhead at the heart of most Silverson mixers. To increase the versatility of the mixer, the stator assembly can be quickly and easily changed. This enables any Silverson mixer to be adapted to perform a wide range of mixing operations including emulsifying, homogenising, disintegrating, dissolving, dispersing, blending, particle size reduction and de-agglomerating. In many cases, Silverson High Shear mixers have taken the place of multiple pieces of equipment.
Workheads for the entire range
In one of Silverson’s latest videos, the main range of screens and workheads is detailed. These include the General Purpose Disintegrating Head, Slotted Disintegrating Head, Square Hole High Shear Screen and the Emulsor Screen. These workheads can be supplied with any Silverson mixer (excluding the Silverson Ultramix) from laboratory scale, to pilot scale batch mixers through to larger In-Line mixers and production scale powder/liquid mixers.
For example, the General Purpose Disintegrating Head is ideal for general mixing applications. It is the most versatile of all the heads, giving an exceptionally vigorous mixing action. Its uses also include disintegrating solids and preparing gels and thickeners, suspensions, solutions and slurries.
For processing more fibrous materials, such as animal and vegetable tissue, the ‘cutting’ action generated by the Slotted Disintegrating Head would be more beneficial for these applications. Other uses for this head include disintegrating and solubilising “elastic” materials such as rubbers and polymers.
The Square Hole High Shear Screen is named as such due to the uniform, square holes of the stator. This screen is able to achieve exceptionally high shear rates, making it ideal for rapid size reduction of soluble and insoluble granular solids. It can also be used for the preparation of emulsions and fine colloidal suspensions.
Another workhead suitable for the preparation of emulsions is the standard Emulsor Head and Emulsor Screen. These screens are available in fine and medium perforations and are especially useful for all emulsions, as well as other liquid/liquid blending.
Increasing versatility at R&D and Laboratory scale
The Silverson L5M-A multipurpose Laboratory mixer can be used with over 40 different interchangeable mixing assemblies. The mixer is supplied with a General Purpose Disintegrating Head, Square Hole High Shear Screen, Standard Emulsor Screen and Axial Flow Head as standard. But other special heads, such as those detailed below, are available as optional extras allowing customers increased versatility during the R&D stages of production.
The Axial Flow Head is supplied with the L5M-A as standard, this special head expels materials vertically upwards. This heads main use is in applications where aeration needs to be minimised. It may also be used to maintain heavy insoluble solids in constant circulation.
As an optional extra Silverson Laboratory mixers can be supplied with Tubular Mixing Assemblies. This series of interchangeable tubular mixing units is suitable for use in narrow-necked containers with capacities from 1 – 500ml.
Other mixing assemblies compatible with the L5M-A include the Duplex Assembly, comprising of two workheads facing in opposite directions. This combined use of two workheads makes the Duplex ideal for high viscosity mixes and applications where light or buoyant material (powders, rubbers and polymers, etc.) need to be drawn down from the surface of a mix and rapidly dispersed. This workhead, as well as the Ultramix mixing assembly, are laboratory-scale equivalents of larger production scale in-tank mixers in the Silverson product range, allowing for easy scale up.
The Laboratory mixer can also be fitted with In-Line assembly which converts it into an In-Line mixer/homogeniser capable of a throughput of approximately 20 litres/ minute, on low viscosity liquids.
Multistage workheads for increased shear at small and large scale
Launching later this year the 088/150 UHS will be the first small-scale Multistage In-Line mixer from Silverson Machines. It matches the capabilities of the production scale Multistage In-Line mixers already available. The multistage workhead increases the number of shearing actions per revolution of the rotor, resulting in substantially faster mixing times and increasing the number of products that can be processed in a single pass.
The Multistage workhead also allows customers to configure the mixer to their specific requirements, for example, the inner stator can be configured as a General Purpose Disintegrating Head, while the outer stator could be a Slotted Disintegrating Head. Depending on the desired results the stators can be a number of different combinations which can be quickly and easily changed to optimise processing and increase mixing versatility.
For more information on any of the Silverson mixers or workheads, get in touch with Silverson Machines or visit www.silverson.co.uk.
