Skip to main navigation Skip to main content Skip to page footer
amixon GmbH amixon GmbH
Amixon
Request a mixing trial
Contact

What are typical batch ranges and throughputs that a modern vertical mixer can cover?

Typical batch ranges and throughputs of modern vertical mixers

Modern vertical mixers are designed for a broad spectrum of applications, from the laboratory to large-scale production. They offer a wide range of batch sizes and throughputs. These depend on the design, the tool geometry, the product properties (bulk density, flow behaviour, moisture, particle size) and the required degree of mixing quality.

Typical batch sizes (usable volume)

  • Laboratory and pilot-plant machines: approximately 5–100 litres (typically used in R&D, recipe development and sample production).
  • Pilot and small series units: approximately 100–500 litres.
  • Production mixers (medium segment): approximately 500–3,000 litres.
  • Large mixers: approximately 3,000–10,000 litres, in special designs up to more than 30,000 litres of usable volume.
  • Silo mixers/special applications: for large batches, for example in the plastics or food industry, volumes of up to approximately 100,000 litres (approximately 100 m³) are possible.

The usable range is determined by the permitted fill level. A comparatively narrow fill level window that uses only part of the geometric volume is customary in the market. Depending on bulk solids behaviour and mixing kinematics, modern designs can also achieve a good mixing quality at considerably reduced fill levels. This makes them suitable for varying batch sizes.

Typical throughputs

Vertical mixers operate predominantly in batch mode. Throughput results from the batch size, the mixing time and the ancillary times (charging, discharging, cleaning).

Mixing times are typically 30 seconds to 10 minutes, and longer with additional process steps (for example coating, granulating, drying).

Batch cycles: depending on the degree of automation and the product, usually 3 to 20 batches per hour.

Hourly throughput:

  • at laboratory scale: a few kg/h,
  • in production: several tonnes per hour up to more than 60 tonnes per hour with large plants and free-flowing bulk solids.

Example: a vertical mixer with 2,000 litres of usable volume and a bulk weight of 0.5 kg/l achieves a theoretical throughput of around 4,000 kg/h when operated with four batches per hour.

Factors influencing batch range and throughput

  • Product properties: cohesive powders, moist or strongly frictional bulk solids require longer mixing times than free-flowing granules.
  • Required mixing quality: higher homogeneity requirements (for example CV below 2–5 %) lengthen the mixing time and reduce the effective throughput.
  • Discharge and charging geometry: outlet connections, conveying technology and the flowability of the material influence the ancillary times and thus the number of batches per hour.
  • Cleaning requirements: frequent product changes and high hygiene standards increase cleaning times. Good accessibility (inspection doors, CIP systems), by contrast, improves the effective plant availability.
  • Operating conditions: the temperature range, the pressure level (for example vacuum to overpressure), the ATEX requirements and the permissible shear stress on the product affect the design and thereby indirectly influence the achievable throughputs.

Recommendation for the design

For a robust design of a vertical mixer, mixing trials should be carried out with the real product. The following factors are to be taken into account:

  • the required homogeneity and the permissible mixing time,
  • the sensitivity to shear,
  • the bulk density and the flow behaviour as well as
  • the planned production logistics (pure batch operation versus quasi-continuous operation).

These factors are assessed systematically in order to determine the appropriate size, the fill level window and the throughput performance that can be expected.

Batch ranges and sizes: the amixon® range extends from 5 litres to 100 m³

Depending on the design, modern vertical mixers can cover very small to very large batches. At amixon® the spectrum extends from approximately 5 litres to 50,000 litres; for large batches the Gyraton® even offers up to 100 m³.

What makes amixon® special

The most important particularity of amixon® conical mixers is their very large usable volume range. They can mix powdered substances homogeneously from a fill level of approximately 5–10 % and, depending on the product, work very stably up to approximately 100 % of the usable volume. A single mixer therefore often covers a batch range of approximately 1:10, without a second machine necessarily being required for changing lot sizes.

A further advantage is that with solids mixers the fill level relates to the usable space of the mixer and not to complete filling. With powders a gas space is always necessary so that the bulk material can be loosened and moved homogeneously at all. Unlike with low-viscosity liquids, complete filling is therefore not sensible.

With conical mixers precisely this flexibility is particularly pronounced: they deliver consistently good mixing qualities across a large fill level range.

Typical sizes and throughputs

  • Single-shaft mixer EM: approximately 5 to 200 litres.
  • Container mixer COM: approximately 100 to 4,000 litres.
  • Vertical and conical mixers VM, HM and AM as well as mixing dryer reactors VMT and AMT: available on request in 100-litre increments from 100 to 50,000 litres.
  • Gyraton® GM: designed for large batches up to approximately 100 m³, with very low drive power.
  • AMK for continuous processes: approximately 1 to 135 m³/h.

An important practical point for the design

For the price-performance comparison, the specification is decisive. It should state the minimum and maximum batch mass as well as the minimum and maximum bulk density of the finished mixture. Only in this way can the working volume actually required of a mixer be determined correctly.

When comparing different makes, type designations must not be set directly against one another, because manufacturers define their sizes differently. Some refer to the gross volume, others to the net volume or usable volume. A fair comparison is only possible where the volume actually usable is taken as the same basis.

As a rough guide the following applies: with many mixers the gross volume lies considerably above the usable volume; the exact relation must, however, always be checked manufacturer by manufacturer.

Why this is particularly relevant for amixon®

amixon® conical mixers are so flexible because they can cover not only large batches but also changing lot sizes economically. This is particularly valuable for operations with frequent product changes, variable batch sizes or several recipes on the same line.

The pilot plant as verification

Before an investment, verification in the pilot plant is advisable at amixon®. Trials are carried out there with the original product, at real fill levels and under the intended temperature and pressure conditions. Mixing quality, product protection, energy input, cleanability and reproducibility in later series operation are assessed.