In many industrial processes, mixing is treated as a supporting operation rather than a primary design variable. Conventional stirred tanks remain the default choice across chemical, biochemical, and pharmaceutical industries, often selected early in the flowsheet and rarely reassessed. However, increasing pressure on energy efficiency, process robustness, and downstream stability is driving renewed attention to mixing concepts and their impact on overall process performance.
Why are mixing concepts being revisited?
Mixing plays a critical role in determining local energy input, flow patterns, and residence time distribution within process vessels. As processes become more sensitive to variability, particularly in applications involving solids, multiphase systems, or shear-sensitive materials, the limitations of conventional mixing approaches become more visible. Design choices that were once considered adequate can introduce inefficiencies, fouling risks, or scale-up challenges under modern operating constraints.
This has led both industry and academia to re-examine whether traditional stirred tanks are always the most suitable solution for complex mixing duties.
What does recent independent research say about vibromixers?
A recent independent review published in Chemical Engineering & Technology (2026) examines vibromixers as an alternative to conventional stirred tanks, focusing on design principles, hydrodynamics, performance characteristics, and industrial applications.
The review highlights that vibromixers rely on oscillatory motion rather than rotational impellers to generate fluid flow and solids suspension. Instead of a rotating shaft, a perforated plate oscillates at high frequency and low amplitude, generating alternating pressure zones that produce strong, controlled axial recirculation. This fundamental difference leads to distinct flow regimes and energy distribution characteristics compared to conventional stirred tanks.
Gimba et al., Vibromixers as an Alternative to Stirred Tanks: Design, Performance Characteristics, and Applications, Chemical Engineering & Technology, 2026. Independent paper: Read here
Turbulence onset: a critical difference
One of the more significant findings concerns the transition to turbulence. Vibromixers reach turbulent flow at far lower Reynolds numbers than conventional stirred tanks, meaning efficient mixing is achieved at substantially lower energy input.
| Flow Regime | Vibromixer | Stirred Tank |
|---|---|---|
| Laminar | Re 10 – 100 | Re < 10 |
| Turbulent | Re 20 – 300 | Re > 10,000 |
Energy consumption comparison
The performance gap is most visible when comparing specific power input. Literature data cited in the review shows the following:
| Mixing System | Power per Volume (W/m³) |
|---|---|
| Solid plate vibromixer | 1,530 |
| Perforated vibromixer | 510 |
| Rushton disc turbine (stirred tank) | 8,600 |
A perforated vibromixer operates at roughly 17 times lower specific power than a conventional Rushton turbine. For energy-conscious processes or those with strict temperature control requirements, this difference is practically significant.
Mixing time performance
Dimensionless mixing times follow the same trend:
| System | Dimensionless Mixing Time |
|---|---|
| Vibromixer | 1.5 – 3 |
| Conventional stirred tank | 10 – 100 |
This reflects the efficiency of axial recirculation as a bulk homogenization mechanism, particularly in taller or more complex vessel geometries.
How does mixing influence downstream performance?
Mixing conditions upstream directly affect downstream unit operations. In processes involving crystallization, precipitation, or solid-liquid separation, local shear rates, concentration gradients, and suspension stability influence particle size distribution, agglomeration behavior, and filterability.
The independent review emphasizes that homogeneous energy input and controlled flow patterns can reduce the formation of fines, limit localized overprocessing, and improve consistency of particle formation. The absence of a central vortex and the dominance of axial over tangential flow also contribute to more uniform suspension in solid-liquid systems, including effective drawdown of floating solids.
Scale-up and operational implications
Scale-up remains a central challenge in industrial mixing. Conventional stirred tanks often require increased impeller size, rotational speed, or installed power to maintain performance at larger volumes. Vibromixing approaches scale differently by decoupling mixing intensity from rotational speed and vessel geometry. Oscillatory velocity, governed by amplitude and frequency, can be adjusted independently of vessel size.
The mechanical simplicity of the design, no rotating shaft seals, no impeller blades, no baffles required, also reduces maintenance exposure and supports sterile or vacuum operation without additional engineering complexity.
How does FUNDAMIX® relate to this research?
DrM’s FUNDAMIX® vibromixer operates on the same oscillatory principles described in the independent review. It uses an electromagnetically driven perforated plate with conical perforations that allow directional flow control, enabling either up-pumping or down-pumping depending on process requirements.
The technology has a longer history than the recent academic interest might suggest. The FUNDAMIX® was originally invented in the late 1960s by Dr. Hans Müller, founder of DrM and Chemap AG, making DrM one of the earliest pioneers of high-frequency vibration mixing for industrial processes. The system was re-engineered and reintroduced in 2012 with modern materials and automation, but the underlying principle has been proven in industrial environments for decades.
The technology has seen broad industrial application in mammalian cell culture, fermentation, vaccine production, and biopharmaceutical processes, where the combination of gentle bulk mixing, low shear, sterilizable design, and vacuum compatibility is particularly well suited. The independent review acknowledges that electromagnetic vibromixers of this type are widely used industrially, while noting that detailed academic hydrodynamic characterization is still developing, a common pattern for technologies where industrial deployment preceded formal academic modeling.
A summary comparison of key parameters:
| Parameter | FUNDAMIX® Vibromixer | Conventional Stirred Tank |
|---|---|---|
| Moving element | Oscillating plate | Rotating impeller |
| Turbulence onset | Low Re | High Re |
| Specific power input | Low | Higher |
| Vortex formation | None | Yes (if unbaffled) |
| Seal complexity | Low | Higher |
| Axial pumping | Strong | Impeller-dependent |
| Maintenance | Low wear | Higher mechanical wear |
| Sterile / vacuum operation | Well suited | Requires additional design measures |
Why is this relevant for process engineers?
The data points presented here, power consumption, turbulence onset, and mixing time, provide a practical framework for comparing mixing options during early process design or when reassessing existing configurations. For engineers working with shear-sensitive materials, multiphase systems, or processes where downstream separation quality is critical, vibromixing represents a technically grounded alternative worth evaluating.
References:
Independent academic review: Gimba et al., Vibromixers as an Alternative to Stirred Tanks: Design, Performance Characteristics, and Applications, Chemical Engineering & Technology, 2026.
https://onlinelibrary.wiley.com/doi/10.1002/ceat.70149
