DO YOU KNOW THE DIFFERENCE BETWEEN A DISPERSER AND AN OVERHEAD STIRRER?

10/06/2023

Dispersers and stirrers are some of the most widely used laboratory bench-top equipment. While they look similar, they are different and there are some considerations to take into account when choosing between one and the other. Learn how to choose according to your application and sample type.

DO YOU KNOW THE DIFFERENCE BETWEEN A DISPERSER AND AN OVERHEAD STIRRER?

Stirring and mixing are essential tasks in the lab. These operations enable labs to meet different goals: from the manufacture of final products to the preparation of samples for further analysis.

The market offers many solutions for this, which often appear similar but can be very different, as in the case of dispersers/homogenisers and overhead stirrers.

Do you know what makes them different and when to choose one rather than the other? We would like to provide you with some important insights to help you distinguish the two solutions and understand which one is needed according to your application and sample type.

MAIN DIFFERENCES BETWEEN DISPERSERS AND OVERHEAD STIRRERS

The first important consideration is the sample type and the components' solubility.

Overhead stirrers are typically used in applications requiring the stirring and mixing of one or more soluble components. If your purpose is to stir two or more non-soluble media, you need to use a disperser to break up the particles and create a stable mixture. In addition to mixing, dispersers can be used to emulsify, suspend, grind, disperse and dissolve various samples.

Besides this significant distinction, other essential features to consider and which differentiate the two instruments are:

1. VISCOSITY

A rotor/stator disperser is optimized to work best with low-viscosity samples.
An overhead stirrer also accepts very viscous samples and works with applications where the viscosity of the sample increases during agitation.

2. VOLUME

Rotor-stator dispersers handle fluids with a relatively small volume (up to 2.5 litres circa).
Overhead stirrers are suitable for very large volumes, up to 100 litres.

3. SPEED

A disperser works at significantly high minimum and maximum speeds (from 3,000 up to 25,000 rpm for the new OV 625 Digital). In these applications, the maximum speed is very important because it significantly reduces the processing time and prevents sample damage due to exposure to heat.
Overhead stirrers also run at very low speeds, and the maximum speed is still lower than that of a disperser.

DISCOVER THE VELP OFFERING: RELIABILITY, SAFETY AND HIGH PERFORMANCE IN EVERY APPLICATION

VELP offers a wide range of solutions that support laboratories in these applications.

1. DISPERSERS
If your requirement is to disperse, homogenize, emulsify or suspend two or more insoluble phases, the new OV 625 Digital offers high shearing force and excellent performance, as well as unparalleled precision, reliability and ease of use.

Learn more about the new OV 625 Digital >>

2. OVERHEAD STIRRERS
If your need is to stir or mix one or more soluble samples together, the OHS Series offers state-of-the-art performance and high resistance in continuous operation, even with the most demanding applications.

The OHS series solutions are powered by a high-performance brushless motor that ensures long life and exceptional reliability. In addition, the VELP technology guarantees constant torque regardless of speed and viscosity changes.

Find out how to choose your next rod stirrer >>

Whatever your challenge, you can rely on precise, reliable and robust solutions, and entrust a highly competent team to assist you in finding the best solution based on your needs.

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