How To Use Our High Shear Mixers

High Shear Technical Tips



High Shear ~ Technical

Top Entry Deployment

high shear domestic socket The quickest way to make your high shear mixer operational, is to suspend it from a hoist, so that the impellor is positioned at half or one quarter of the liquid height. The half to one quarter rule imposes a restriction on total liquid height, because the high shear mixer should not ordinarily be immersed to a depth greater than 40 cm. This implies a max liquid height of 0.8m. If your vessel is 2m high, you are never going to be able to fill it and still retain thorough mixing. This is where side entry becomes useful.

We do not recommend filling vessels to the top, because the powerful turbulence of the high shear mixer will cause spillages. If you need to completely fill your target vessel, then you should incorporate the mixer into a gasketed lid.

Side Entry Deployment

Side entry deployment enables the impellor to be positioned near the bottom of larger vessels of up to 250 litres in volume. This is helpful, particularly in applications where undissolved solids tend to sink to the bottom. The proximity of the impellor to the bottom ensures that all lingering matter is powerfully sucked into the mixer and assimilated.

In side entry applications, the bearing plate of the mixer expects to mate with a flat sided vessel, like a tote bin. If the vessel you intend to use has round sides, your local steel fabricator will have to weld a circular flange mount into the side of your chosen vessel. Clearly, if you think your batch size is going to be between 150 and 400 litres, you might want to look around for a second hand stainless steel vessel with flat sides. This will save you both time and expense. We offer considerable help to steel fabricators making this modification.

Supporting the Motor in Side Entry Applications

In side entry applications, gravity exerts a strong force upon the electric motor. The motor therefore needs to be supported and the grab handles make this very easy to do. Some tie the grab handles to the top of their vessels using steel rope. Others use rachet straps. Those who have access to a TIG welder sometimes weld a cradle to the side of the vessel, for the motor to rest on. All the above methods have their merits. Failure to address the issue of motor support in side entry applications may lead to gasket leaks, or even metal fatigue in your vessel.

Making The High Shear Mixer Faster

The faster the impellor turns, the higher the shear. Some applications will need higher shear than you can create at 1400 rpm. 1400 rpm is the default maximum for the RAREL Rules Mixer / Homogeniser. For those applications requiring extra shear, the speed controller can be tweaked to drive the motor at more than 1,400 rpm. In fact, you can make the motor turn so fast, that it quickly destroys itself.

However, any prolonged use at over 1400rpm will reduce the life expectancy of the motor, the food grade bearing on the bearing plate, and the oil seal. We permit running at up to 2,800rpm only in certain carefully controlled applications. At 2,800 rpm, the life expectancy of the above components above will be a bit shorter, though ALL components are specified for 2,800rpm or more. However, as you are buying components cheaply, direct from the suppliers, and fitting them yourself, you may regard this as an acceptable trade-off for greatly increased shear.


There is only one RAREL Rules model of high shear mixer. However, it incorporates several features designed to help Builder Owners customise their machines. For example, some of the screw threads are longer than they need to be, so that Builder Owners can devise and fit their own accessories.

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