Refit of conical orbital screw mixers, drying mixers, coolers, and reactors to the AVA helix system

AVA is the market leader in the field of vertical conical mixers and drying mixers.
The AVA mixing helix system has proved itself in industry applications and offers huge advantages over the orbital screw system. In order to allow customers to update existing conical screw systems with rotary screws and internal angular geared base to the state of the art without having to purchase new machines, AXA has developed a method for integrating helix systems into existing conical screw mixer and dryer housings.

Advantages of the AVA Helix System

  • Maintenance and servicing costs are practically eliminated as the angular geared base systems are replaced.
  • Increase in usable volume of the existing mixer/drying mixer of up to 30%.
  • Up to four times shorter mixing times due to application of the AVA mixing helix.
  • Treatment times reduced by up to a factor of 3 when drying, cooling, and heating due to application of the AVA mixing helix.
  • Additional option to utilize agglomerate crushers directly in the product chamber in order to achieve a finer end product.
  • In comparison to screw mixers, which require two drives (one for the screw and another one for the circulating operation), the AVA helix only requires one drive.
  • Mixing shaft and mixer helix can also be heated, which results in approximately 5–6 times faster treatment times when drying, cooling, and heating.

Installing the Mixing Helix

Orbital conical screw mixers generally have a welded cap/dished vessel head and contain a manhole nozzle. This manhole nozzle is used to insert the fully pre-built plugin helix system and then weld it to the vessel. The old existing flange feed-through for the shaft and seal is maintained for the new system. A new sealing with strut bearing and drive is mounted for this purpose.

The AVA mixing helix is self centering and therefore essentially requires no additional bearing. The modification has already been performed to the full satisfaction of our customers for machines with capacities of up to 25,000 liters.


On-site retrofit generally takes between two and five days, depending on the size of the machine.

If the orbital screw design has a tendency to form an agglomerate, the AVA mixing helix system allows you to additionally install a separately powered agglomerate crusher in the lower part of the machine.

Machines produced by the following manufacturers can be modified:

  • Krauss Maffei
  • Hosokawa Nauta
  • Bolz/Summix
  • Any other machine that implements the orbital screw principle

Experience has shown that the required investment for the modification pays for itself within a maximum period of 12 to 36 months thanks to the increased production performance.


We would be delighted to demonstrate the advantages of the helix system to you at our technology center. Machines are available with operation volumes between 30 and 150 liters.

Deciding Facts – Refits

  • Minimal contamination risk
    Shaft seals and bearings do not leak into the product.
  • The mixer intensity can be adapted to the product characteristics
    Gentle folding or intensive blending can be achieved, depending on the rotation speed and design of the agitator.
  • Short drying times
    Permanent blending and intensive contact between the product and the heated side wall ensure above-average heat transfer.
  • Short mixing times
    The entire product volume participates in the mixing process.
  • The drying mixer can be used as an evaporator.
    Suitably designed agitators are also ideal for concentrating liquids and elutriation.
  • Increased drying and evaporating capacities due to heated agitator
    The agitator can be heated and shaped in such a way that an extremely high evaporation performance can be achieved.
  • Reliable and trouble-free maintenance
    The simple design serves to minimize maintenance costs.
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