What Is a Liquid Mixer?
A liquid mixer allows you to quickly and thoroughly mix ingredients. This process is used in a wide range of applications from creating stable emulsions to blending and homogenizing.
This type of mixing can be performed in batches or continuously. For example, continuous liquid blending is a common practice in the textile industry to ensure that dye lots remain consistent.
Viscosity
Many industrial applications involve high viscosity materials. Mixing them is often difficult and requires advanced knowledge of the chemistry of the fluids in question as well as the specific agitation requirements. Optimum mixing results are seen as a uniform, homogeneous solution that is free of agglomerates. This is easily achieved in less viscous materials such as water-like liquids but much more challenging with thicker materials.
Viscosity is a measure of resistance to gradual deformation of a liquid. It is an important property of a liquid because it influences the ease with which the liquid can be pumped or moved from one place to another. It is also an important criterion in the design of equipment used for handling liquids because viscous fluids have lower flow rates than thinner fluids.
The viscosity of a liquid may change over time due to temperature changes or other environmental factors. Therefore, it is important to know how to adjust the speed of the agitator to compensate for this change. Similarly, the agitator must be designed to accommodate changes in viscosity caused by the addition of solid particles or other agents that may increase the viscosity of a liquid.
There are two ways of measuring a fluid’s viscosity: one measures the resistance of a fluid to an external force, called dynamic viscosity. The other measures the resistance of liquid mixer a fluid to the action of gravity, called kinematic viscosity. For most applications, kinematic viscosity is more useful than dynamic viscosity because it does not depend on temperature.
Flow
A liquid mixer keeps two or more liquids mixed together and uniform in a vessel. This can be accomplished using laminar or turbulent flow, and is determined by the viscosity of the mixture, density characteristic of the vessels and the speed of the mixer.
Mixing reduces concentration and temperature gradients, which is particularly important in a variety of industrial processes like dissolving, electrolysis, crystallization, absorption, extraction, heating or cooling and heterogeneous chemical reactions that proceed mostly in liquid media. Mixing also helps deagglomerate solids in suspension – especially fine powders and spray dried materials that can form lumps during transportation or storage.
In addition to reducing concentration and temperature gradients, mixing improves the transfer of heat and mass between different components of a system. This is important in many industrial applications, for example, when a catalyst or solid microbes are combined with liquid reagents during chemical reactions.
Liquid-Liquid mixing is usually done by a high shear, high flow mixer (such as a Rushton turbine or Smith turbine), however, it may be necessary to use a low shear mixer for certain products (e.g., liquid-gas). All INFINI-MIX dynamic mixers are low shear and can be used for Liquid-Liquid, Gas-Liquid and Solid-Liquid applications. Our wide range of rotor/stator combinations ensure that we can provide the right type of mixer to meet your process requirements.
Shear
A liquid mixer uses a rotor blade system to create shear in the product. Shear occurs when one area of a fluid travels at a different velocity than another area. A rotor or impeller is located in the center of the mixer and moves in and out of a static stator to “work” the product creating shear and flow. This shear forces dispersed particles or droplets together and breaks them down into a continuous phase, often producing an emulsion.
High shear mixers are also used to reduce particle size or granulate solid products. This is usually done in conjunction with a binder or granulating liquid. Once a desired size is reached the powdered material can be shaped into larger and denser agglomerates using the shear mixer system.
An inline high shear homogeniser is ideal for mixing and dispersing slurries. This can be difficult to achieve with a traditional agitator due to the difference in viscosity between the two liquids. Homogenisation can be achieved down to globule or droplet sizes of 2 – 5 microns, but finer results down to 0.5 microns are possible depending on the application. This level of homogenisation is often required for pharmaceutical and cosmetic products and is much faster to achieve than a high pressure homogeniser which requires a pump to apply large amounts of force to the product through a small adjustable aperture at a very high pressure.
Temperature
In many industrial liquid mixing applications, the final mixture temperature is important. Mixing at a lower or higher temperature than the starting point will result in the creation of a new mixture with different characteristics.
To avoid this, the liquid mixer needs to be able to keep the product at a uniform temperature. For this, the mixer must have a Packaging Machinery Supplier heating system. Usually, this is achieved by using a jacket on the mixing vessel.
This ensures that the mixture remains at a consistent temperature, while also ensuring that the mixture is properly heated. Using this method eliminates the need for multiple vessels and provides greater control over temperature.
Another crucial consideration is the ability of the liquid mixer to handle different materials and temperatures. Traditional mixing methods process liquids by creating vortices at the end of blades or propellers. This creates a limited number of small mixing zones that must be individually processed, which can lead to inconsistent results and product quality.
In contrast, RAM technology mixes everywhere instantly and continuously. The primary mixing mechanism is intense liquid to liquid material boundary interaction, driven by Faraday instability and facilitated by vertical vessel movement of up to 60 x/second. For example, mixing 2.5 grams of food coloring with 235 grams of a polymer surrogate in this RAM mixer produces a fully dispersed mixture of both ingredients, shown in high speed footage.
