High Shear Mixers can be beneficial for many applications and processes in a variety of industries. Silverson Machines have been the leader in the design and manufacture of high shear mixing equipment for over 75 years. Here, Silverson answer some frequently asked questions regarding high shear mixers and their uses.
What is a high shear mixer?
A high shear mixer is a device which imparts shear energy into a mixture. This shear energy is generated in the precision-engineered rotor/stator workhead.
What does a high shear mixer do?
A Silverson High Shear mixer is able to mix, emulsify, homogenise, solubilise, suspend, disperse and disintegrate solids due to the easily interchangeable rotor/stator workheads available with most models.
How does a High Shear Mixer work?
The high-speed rotation of rotor blades within the mixing workhead exerts a powerful suction, drawing liquid and solid materials into the centre of the workhead. Centrifugal force then drives materials towards the periphery of the workhead where they are subjected to a milling action in the precision-machined clearance between the ends of the rotor blades and the inner wall of the stator. This is followed by intense hydraulic shear as the materials are forced, at high velocity, out through the perforations in the stator and circulated into the main body of the mix. At the same time, fresh material is continually drawn into the workhead, maintaining the mixing cycle.
Why use a high shear mixer rather than a simple agitator?
Agitators can give satisfactory results for simple duties such as blending like-viscosity liquids, providing in-tank uniformity and promoting heat transfer in jacketed vessels. But because conventional mixing equipment, such as simple agitators, does not produce any shear energy it is incapable of performing more complex mixing duties. For example, an agitator cannot form a uniform, stable emulsion as no shear energy is imparted into the mixture. Although the phases may appear to have been mixed, once agitation is stopped the phases will separate. Without shear energy, the globule size of each phase cannot be sufficiently reduced to maintain stability. The agitator simply moves them around the vessel.
What processes can High Shear Mixers be used for?
High Shear Mixers can be used for all kinds of processes including powder/liquid mixing, reclamation, particle disintegration and blending to name a few. You can find more information on the Process page of the Silverson website.
What products can be manufactured using a High Shear Mixer?
Hundreds, if not thousands, across a wide range of industries. You can read about some in the Silverson Application Reports library.
What’s the difference between a High Pressure Homogeniser and a High Shear Mixer?
High Pressure Homogenisers are powerful devices that use a piston pump to force the product through a very small adjustable aperture at high pressure. The product is subjected to intense energy forces reducing the particle or globule size down. These machines are used for products which require sub-micron particle size. Generally throughput is low and the energy requirement is very high. By comparison, High Shear Mixers are much more energy efficient and the high speed, high shear mixing action can achieve particle or globule sizes in the range of 2 – 5 microns, or down to 0.5 microns, in some cases, depending on the formulation, with a much higher throughput and lower maintenance requirements.
We produce a number of different products: can I use a High Shear Mixer for more than one application?
The advantage of Silverson High Shear mixers is that any one machine can perform the duties that in the past may have required several different pieces of process equipment due to the interchangeable rotor/stator workheads. Our in-tank mixers can be used on mobile floor stands, making them easy to move from vessel to vessel for processing multiple products.
Can I use a High Shear Mixer at Laboratory Scale?
Yes – in fact, using a High Shear Laboratory mixer is a great way to test the technology with different applications and are especially suited to R&D work. High Shear Mixing at Laboratory scale also provides an accurate means of forecasting the results of high shear mixing at a larger scale.
What is the cost of a High Shear Mixer?
The cost of a high shear mixer will depend on the model, batch size, application and materials of construction. However, Silverson High Shear mixers can reduce processing times by up to 90% so money invested in a high shear mixer is soon recuperated through savings made in processing time, energy and even raw material costs.
Which High Shear Mixer is right for me?
You can take a look at the range of High Shear Mixers available on the Silverson website. But the best way to find out which mixer would suit individual processing requirements best is to contact the mixing experts at Silverson.