Flexible Modular Designs for all Mixing Tasks and Viscosity Ranges
EKATO Rühr- und Mischtechnik GmbH, global market leader in mixing and dispersion technology, has a modular mixing system that can process products across all normal viscosity ranges. Different variations of the EKATO PARAVISC system are being used for the production of pharmaceuticals, for cosmetics such as salves, for gels, toothpastes, shampoos and for various foodstuffs. Another area where they are used is in the production of paste-like products such as automobile protective coatings, glues, paints, varnishes and building materials.
By combining various individual components, the flexible modular design system can address the most diverse mixing requirements. This can enable one vessel to be designed to perform process steps that previously had to be performed in separate vessels, and/or to process a diverse range of products in one vessel. Various components of the modular system can be installed in order to address the need for versatility and/or demanding mixing tasks.
Advantages compared to other mixer types
The main component of this mixing system is the EKATO PARAVISC. Products in a viscosity range of 1 to 1,000,000 mPa s can be mixed by this type of impeller. The PARAVISC is a near-wall, axial pumping impeller that is typically used for blending highly viscous media. It is a positive displacement impeller, similar a helical ribbon impeller. However, in contrast to a helical ribbon, the design of the PARAVISC only requires radial arms near to the base of the vessel. Therefore it is possible to install internal baffles and/or eccentrically arranged agitators that cover almost the entire filling height range. Compared to traditional anchor impellers the PARAVISC provides superior blending and entrainment due to the axial flows induced. The blending time constant n*? of the PARAVISC lies within the range n*? = 20 – 60 across all viscosity ranges.
Intelligent combination of agitation components
Wall scrapers can be mounted on the PARAVISC using round vertical supports so that they can move to accommodate unevenness and irregularities in vessel shape. Wall scrapers are particularly useful to minimize fouling on vessel walls and when residue is to be minimized, for instance during discharge, or when heat transfer must to be improved. The design of the wall scrapers can be varied to address specific characteristics of the product. Robust, non-adjustable scrapers are primarily used where crust formations occur. GMP-compliant flexible scrapers are often used for pharmaceutics and cosmetics applications; they adjust to unevenness with help of the product flow alone, and do not need springs.
Another useful component is the dissolver-disc. This can be used as an off-center mixing system and combined with a PARAVISC to fulfill demanding dispersing tasks. A typical application for this combination is adding and dispersing large amounts of fillers such as starch, lime, silica or synthetic powders into viscous liquids.
The geometry of the base of the PARAVISC impeller can also be modified to optimize discharge of product from the vessel. For instance, using a Z-shaped anchor that moves the product to the central outlet of dished vessels. For conical bottoms the PARAVISC geometry can be adapted to the shape of the cone, pushing product towards the vessel outlet.
In some cases the bottom section of the PARAVISC is left open in the center. This may be done, for instance, if there is a risk that solids might block the vessel outlet. The gap allows installation of a high-speed bottom impeller, driven by a separate concentric shaft, to perform the solids suspension task.
A PARAVISC pumping upwards can be used to accelerate degassing of highly viscous products. This option creates low shear but still provides surface movement. Small bubbles coalesce to larger bubbles; the bubbles collect and deform at the product surface and hence disengage more quickly from the liquid.
Ideal entrainment
The PARAVISC can be combined with various other mixing systems to form coaxial agitators. These are used for high viscosity applications or very demanding entrainment requirements. Vortex formation is increased when both agitator shafts rotate in the same direction, leading to behavior ideal for entrainment. The two shafts of a coaxial agitator can also be rotated in opposite directions - reducing vortex formation and leading to higher shear forces compared to single shaft systems. It is also possible to achieve a “kneading” action by using a large diameter central impeller and rotating the PARAVISC and central impeller(s) in opposing directions. The PARAVISC can also be combined in a state-of-the-art design with a rotor-stator system to achieve minute particle or droplet dispersions.
Reliable scale-up guaranteed
EKATO has test facilities that enable trials using the actual product mixture. In addition EKATO has expert systems and design programmes to help determine blending and dispersion times, heat transfer as well as mechanical loads on the agitator, the vessel and other vessel internals. Trials are usually performed at EKATO’s Technical Centers in Germany or the USA in 50 liter glass or metal vessels. Trials can be performed at up to 200 °C and under pressure or vacuum.
The mechanical design of the EKATO agitator takes requirements such as a GMP-compliance and simplified installation into consideration. Provision of accurate clearances between agitator and vessel wall are especially important for close-clearance mixing systems. If necessary, EKATO can supply the vessel as well as the agitator and all auxiliary internal equipment.
The EKATO PARAVISC can be used in combination with various central-mixing systems to form a coaxial agitator for very high viscosity applications or for extremely demanding entrainment and dispersion tasks.
The EKATO PARAVISC
The EKATO PARAVISC Mixing System:
Flexible Modular Designs for all Mixing Tasks and Viscosity Ranges
EKATO Rühr- und Mischtechnik GmbH, global market leader in mixing and dispersion technology, has a modular mixing system that can process products across all normal viscosity ranges. Different variations of the EKATO PARAVISC system are being used for the production of pharmaceuticals, for cosmetics such as salves, for gels, toothpastes, shampoos and for various foodstuffs. Another area where they are used is in the production of paste-like products such as automobile protective coatings, glues, paints, varnishes and building materials.
By combining various individual components, the flexible modular design system can address the most diverse mixing requirements. This can enable one vessel to be designed to perform process steps that previously had to be performed in separate vessels, and/or to process a diverse range of products in one vessel. Various components of the modular system can be installed in order to address the need for versatility and/or demanding mixing tasks.
Advantages compared to other mixer types
The main component of this mixing system is the EKATO PARAVISC. Products in a viscosity range of 1 to 1,000,000 mPa s can be mixed by this type of impeller. The PARAVISC is a near-wall, axial pumping impeller that is typically used for blending highly viscous media. It is a positive displacement impeller, similar a helical ribbon impeller. However, in contrast to a helical ribbon, the design of the PARAVISC only requires radial arms near to the base of the vessel. Therefore it is possible to install internal baffles and/or eccentrically arranged agitators that cover almost the entire filling height range. Compared to traditional anchor impellers the PARAVISC provides superior blending and entrainment due to the axial flows induced. The blending time constant n*? of the PARAVISC lies within the range n*? = 20 – 60 across all viscosity ranges.
Intelligent combination of agitation components
Wall scrapers can be mounted on the PARAVISC using round vertical supports so that they can move to accommodate unevenness and irregularities in vessel shape. Wall scrapers are particularly useful to minimize fouling on vessel walls and when residue is to be minimized, for instance during discharge, or when heat transfer must to be improved. The design of the wall scrapers can be varied to address specific characteristics of the product. Robust, non-adjustable scrapers are primarily used where crust formations occur. GMP-compliant flexible scrapers are often used for pharmaceutics and cosmetics applications; they adjust to unevenness with help of the product flow alone, and do not need springs.
Another useful component is the dissolver-disc. This can be used as an off-center mixing system and combined with a PARAVISC to fulfill demanding dispersing tasks. A typical application for this combination is adding and dispersing large amounts of fillers such as starch, lime, silica or synthetic powders into viscous liquids.
The geometry of the base of the PARAVISC impeller can also be modified to optimize discharge of product from the vessel. For instance, using a Z-shaped anchor that moves the product to the central outlet of dished vessels. For conical bottoms the PARAVISC geometry can be adapted to the shape of the cone, pushing product towards the vessel outlet.
In some cases the bottom section of the PARAVISC is left open in the center. This may be done, for instance, if there is a risk that solids might block the vessel outlet. The gap allows installation of a high-speed bottom impeller, driven by a separate concentric shaft, to perform the solids suspension task.
A PARAVISC pumping upwards can be used to accelerate degassing of highly viscous products. This option creates low shear but still provides surface movement. Small bubbles coalesce to larger bubbles; the bubbles collect and deform at the product surface and hence disengage more quickly from the liquid.
Ideal entrainment
The PARAVISC can be combined with various other mixing systems to form coaxial agitators. These are used for high viscosity applications or very demanding entrainment requirements. Vortex formation is increased when both agitator shafts rotate in the same direction, leading to behavior ideal for entrainment. The two shafts of a coaxial agitator can also be rotated in opposite directions - reducing vortex formation and leading to higher shear forces compared to single shaft systems. It is also possible to achieve a “kneading” action by using a large diameter central impeller and rotating the PARAVISC and central impeller(s) in opposing directions. The PARAVISC can also be combined in a state-of-the-art design with a rotor-stator system to achieve minute particle or droplet dispersions.
Reliable scale-up guaranteed
EKATO has test facilities that enable trials using the actual product mixture. In addition EKATO has expert systems and design programmes to help determine blending and dispersion times, heat transfer as well as mechanical loads on the agitator, the vessel and other vessel internals. Trials are usually performed at EKATO’s Technical Centers in Germany or the USA in 50 liter glass or metal vessels. Trials can be performed at up to 200 °C and under pressure or vacuum.
The mechanical design of the EKATO agitator takes requirements such as a GMP-compliance and simplified installation into consideration. Provision of accurate clearances between agitator and vessel wall are especially important for close-clearance mixing systems. If necessary, EKATO can supply the vessel as well as the agitator and all auxiliary internal equipment.
For more information, please visit:
https://edir.bulk-online.com/profile...schtechnik.htm
Photo:
The EKATO PARAVISC can be used in combination with various central-mixing systems to form a coaxial agitator for very high viscosity applications or for extremely demanding entrainment and dispersion tasks.
Attachments
ekato_2 (JPG)
■