Next-generation magnetic agitators

ZETA presents a new magnetic agitator with excellent run-dry capability

ZETA has supplied more than 2000 of its magnetic agitators to more than 150 companies in the food, pharmaceutical and biotech sectors around the world.

‘Even in this highly specialised sector, continuous improvement is the key to long-term success,’ says Reinhard Heber, head of the products and components department at ZETA.

Product Manager Andreas Diel explains: 'In our new BMRT agitators, we’ve used recently developed magnetic materials that have enabled us to create a solution for situations when you want to empty a vessel while keeping the agitator running.’

In the new design, some of the magnetic force is used to lift the impeller. This reduces friction in the impeller's ceramic bearing. In the older models, the impeller settles on the bearing when the vessel is empty, which leads to abrasion, contamination and even bearing failure.

Andreas continues: ‘With the new model, you can keep stirring right down to the last drop. Importantly, the BMRT agitator offers this greatly improved run-dry capability without incorporating any new bearing materials or coatings, completely avoiding the introduction of new abrasion problems.’

As the impeller now ‘rides’ on the magnetic field, the lifting function of the impeller blades is no longer required, so the blade shape can be optimised for mixing. ‘Instead of the old, angled blades, we can now use nearly vertical blades, which we have designed by computational fluid dynamics to achieve a shorter mixing time with the same energy input,’ explains Andreas Diel.

The new magnetic material also makes it possible to transmit a higher torque to the impeller. This means that similarly sized agitators can mix significantly larger volumes of liquid.

ZETA emphasises that it is not changing the popular BMR range of agitators. However, as department head Reinhard Heber concludes: 'We think that with the run-dry capability, the use of more powerful magnets and shorter mixing times, the new ZETA-BMRT agitators will offer significant benefits to many clients.'