Definition
The multi-purpose disperser is a laboratory or pilot-scale general equipment that integrates high-speed shearing, dispersion, homogenization, emulsification and stirring functions. It exerts strong mechanical action on fluids or solid-liquid mixtures through high-speed rotating rotor and stator structures to achieve material refinement, mixing, and homogenization. The equipment has a wide range of applicability in sample preparation and process development in many industries such as chemical, food, coating, new energy materials and daily chemicals.
Principle
The core working mechanism of the multi-purpose disperser is based on the high-speed shearing principle. The equipment drives the rotor to rotate at high speed in the stator cavity, and the rotational speed is usually adjustable within a certain range. When the material is sucked into the narrow gap between the rotor and the stator, it will be subjected to multiple effects such as strong mechanical shear force, high-frequency vibration and hole effect. Together, these forces cause the particles or droplets in the material to break up, disperse and homogenize. The shear rate is related to the rotor linear velocity and the rotor-stator gap geometry, and the approximate relationship can be expressed as: γ ≈ π· D·N/h, where γ is the shear rate, D is the rotor diameter, N is the rotor speed, and h is the gap width between the rotor and the stator.
Measurement and evaluation methods
The evaluation of dispersion often relies on the determination of physical indicators of the treated sample. Common methods include using a laser particle size analyzer to measure the particle size distribution of particles or droplets, and characterizing the dispersion fineness with characteristic particle size parameters such as D50 and D90. The rheological characteristics of the system were measured by viscometer. microscopic dispersion was observed with the help of a microscope; or measure the change in light transmittance or absorbance over time in relation to the stability of the suspension by a spectrophotometer. These measurements are performed with reference to relevant industry standards or accepted test specifications.
Influencing factors
The dispersion effect is affected by multiple factors. In terms of equipment parameters, rotor speed, rotor and stator geometric design, dispersion head size and processing time play a major role. The process conditions include the initial state of the material, solids content, viscosity, temperature control, and addition sequence. Material properties such as particle hardness, surface energy, and polarity of the liquid medium can also significantly affect the final result. In practice, the combination of these parameters needs to be optimized through system experiments.
Applications
The application of multi-purpose dispersers covers a wide range of industries and R&D fields. In the coating and ink industry, it is used for the dispersion and stabilization of pigment slurries; in the food industry, participate in the preparation of sauces, dairy products and other emulsification systems; In the preparation of nanomaterials and battery slurry, the uniform mixing of active substances, conductive agents and binders is realized. In the field of cosmetics, it is used for the homogeneous emulsification of cream products. Its flexible configuration allows it to accommodate a wide range of material systems, from low-viscosity solutions to high-viscosity pastes.
Selection considerations
Choosing a suitable multi-purpose disperser requires comprehensive consideration of multiple indicators. The throughput determines the size of the equipment and needs to match capacity requirements from milliliters to tens of liters. Material properties such as viscosity range and corrosiveness are related to motor power, material corrosion resistance and shaft seal form. The dispersion fineness and uniformity required by the process target affect the selection of rotational speed range, shear strength and rotor-stator structure type. In addition, the scalability, temperature control ability, easy-to-clean design and safety protection functions of the equipment are also important reference factors. It is recommended to test and verify according to specific application scenarios.