SPECIALIST ARTICLE
Fix rebuilt
Multipurpose machines as a solution for order-oriented mixing and dispersing processes
Flexibility is one of the most important requirements today. Production must be able to manufacture a large number of product variants and newly developed products in an order- and user-oriented manner. To ensure this, multipurpose machines were developed for mixing tasks.
In mechanical process engineering, single-purpose machines are still predominantly used, which do not allow any process engineering flexibility. For example, an agitator cannot usually disperse and emulsify. Conversely, a disperser generates high shear effects, which destroys the structure of many products. Furthermore, different tool geometries are required depending on the viscosity and task. This is different with the ystral multipurpose machine. It can be converted from an ideal mixer to a coarse disperser1 to a fine disperser or a combined mixing-dispersing machine in just a few simple steps.
The basis of the machine is a mixer shaft mounted separately from the motor in a stator tube with a single or double mechanical seal. The mixing or dispersing tools are clamped or screwed on in a few simple steps. For requirements in the sterile and pharmaceutical sector, a version is available in which all connections are sealed in accordance with GMP guidelines.
Jet mixerThe jet mixer is the ideal tool for homogeneous mixing and suspending. A fast-running rotor generates a vertical flow of liquid in a stator, which is directed straight to the bottom of the container. This jet splits at the bottom and creates an upward flow on the container wall. In this way, the entire contents of the tank are mixed vertically. This mixing takes place without the introduction of air via a drum or along the mixer shaft. The entire contents of the container are evenly covered so that a complete exchange of substances takes place across all levels.
In contrast to conventional mixing processes, the medium does not rotate in the tank, so that no flow breakers are required. Heavy sediments are also suspended without strong turbulence and distributed absolutely homogeneously in the medium. The jet mixers also reduce the energy input, up to 90% of which is converted into vertical flow.
DispermixSimilar to the jet mixer, a high-speed rotor generates a liquid flow in the Dispermix, but the design of the Dispermix stator splits it into two differently directed flows. The vertical partial flow is directed towards the bottom of the tank and thus ensures large-scale circulation and homogeneous mixing - just like with the jet mixer. A second partial flow is diverted horizontally in the Dispermix head and guided through the dispersing zone of the Dispermix head. The patented Dispermix tool works according to the rotor-stator-dispersing principle and, in addition to thorough mixing of the container contents, ensures particle size reduction of solids and agglomerates or excellent emulsification. It is also able to break down highly thickening swelling agents (CMC, xanthan gum, etc.) quickly and absolutely agglomerate-free.
Batch disperserOne or more rotor-stator pairings with a narrow radial gap ensure a continuously horizontally pulsating conveying flow with high turbulence. The product is accelerated to a high speed by the inner rotor ring and completely decelerated again at the individual teeth on the stator ring. This effectively crushes and homogeneously distributes the solids and/or droplets in the product. This tool is used for emulsions that have to fulfill a very narrow droplet spectrum or can, for example, also produce agglomerate-free pigment suspensions using the wet grinding process.
Magazine: cav
Author: Bernd Weber
About ystral
With our vast knowledge and many years of experience in Process- and Application Engineering we offer targeted, customer-oriented solutions across industries - from lab equipment to production machines or plants. Together with you, we develop concepts and implementations for your individual applications, which mean mmediately realisable and quantifiable added value for you.