The Vortex Chamber
A new type of built-in mixing system for shear stream mixers
The newly developed Lipp-Vortex Chamber which is arranged outside the mixing chamber combines an effective additional mixing system with outstanding characteristics for breaking up agglomerates.
This innovative mixing tool is installed at the side of the mixing chamber. In contrast with other systems, however, no part of the Vortex Chamber projects into the mixing chamber so that the entire surface of the mixing chamber is wiped over by the mixing tools of the main mixer. There are thus no dead space areas resulting from design, such as are found in conventional systems.
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| Picture 1: Interior of mixer with Vortex Chamber | Picture 2: Vortex Chamber with shearing zone |
Operating principle
The rotating movement of the rotor in the Vortex Chamber generates powerful shear forces in a small space. The product is thus drawn in axially in the centre of the chamber, passes the rotor/stator area in which the shearing zone is located and is thrown back through the periphery of the chamber into the mixture.
New product material is continuously conveyed by the mixing tools of the main mixer into the Vortex Chamber area. This guarantees that the entire product comes into the effective area of the chamber and is forced to flow through its shearing zone.
Especially when processes require heat exchange, local temperature gradients are immediately compensated in the case of cooled or heated mixers as a result of product material from the Vortex Chamber being constantly exchanged with the bulk of mixture. Inadmissible local product heating as a result of the introduction of mechanical energy is avoided. In addition, the Vortex Chamber may also be cooled or heated. The special geometry and operation of the Lipp Vortex Chamber allows even larger lumps to be drawn in and to be disintegrated.
Although the Vortex Chamber presents a bulging of the mixing chamber, the high-speed rotor ensures that the product is practically entirely removed from the chamber when the mixer is being emptied. A high level of self-cleaning is thus inherent in the system.
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| Picture 4: Trial mixer with Vortex chamber |
Another design advantage is that already existing paddle mixers of almost all types can be retro-equipped with the Lipp Vortex Chamber without any need to adapt the mixing mechanism of the respective mixer.
The Vortex Chamber is characterized by a high level of effectiveness even at rotating speeds which are considerably below those of comparable systems. This reduces the wear and tear of shearing elements and the shaft seal and often means less power input required to achieve the same degree of effectiveness.
Applications and equipment characteristics
- Mixing of highly viscous additives with fine powders
- Increase the surface areas in drying and reaction processes
- Mixing of small quantities of liquid in fine powdery mixtures (wetting). Atomization of the liquid involved is not necessary.
- A frequency-controlled motor as a drive for the Vortex Chamber in order to adapt the rotating speeds of the rotor to the different process parameters.
- The materials used, the sealing systems, etc. are selected corresponding to customer-specific requirements.
Advantages over conventional systems
- Considerably improved mixing and disintegrating characteristics
- High degree of efficiency with low operating costs, meaning a lower number of mixing tools
- No parts projecting into the mixing area, no dead spaces
- No granulation / compression effects
- High level of self-cleaning effect
- Retro-fittable in almost all types of mixers
- Considerably reduced wear and tear thanks to the low rotational speed