This device is used in many industries for different purposes. The main idea or fundamental use of this device is to generate a local high shear rate or higher shear stress. In our equipment, this device produces a shear rate that is 1–2 orders of magnitude larger than the shear rate generated with a normal standard steel vessel with different kinds of agitators, including radial agitators.
The rotor–stator homogenizer generates a local high shear rate that can be used to create stable emulsification by accelerating the mass transfer rate. Turbulence diffusivity or hydrodynamic diffusivity plays a highly significant role in all biotechnology processes.
I will begin with the primary application of this device, which is to generate a high shear rate in order to induce emulsification. Emulsifications are mainly used in the cosmetics industry, where we want to generate some creams; i.e., water/oil compositions or ointments that comprise two immiscible organic materials. These materials require a high level of shear stress that is not achievable with standard stirrer vessels and agitators. Hence, we introduce in our stirrer vessel a simple rotor–stator homogenizer.
The secondary use of this device is for creating a wet meal, meaning to reduce the particle size of the solids, but not in a dry phase and not the powder by itself. The process involves feeding the solids into a liquid medium and then transferring this slurry through the rotor–stator homogenizer. Because we are applying a very high shear rate, we are able to reduce the particle size, i.e., wet milling. Other uses include processes that involve very fast reactions. In this case, in a normal stirrer vessel, the process is controlled by mass transfer.
Once we introduce our rotor–stator homogenizer in a stirrer vessel and generate shear rate and energy of dissipation at two orders of magnitude more, a high level of diffusivity is achieved, which reduces the capability of materials to meet between two regions and generate a reaction. This improves the main reaction and, hopefully, secondary reactions will be sufficiently slowed to allow finalizing the product. This method is common in the biotechnology industry. For example, as a result of the growing quantities of cells in our tank during fermentation, and in order to extract the material from the cells, we need to rupture the cell membranes. This can be done by applying a higher shear rate than we are able to do with the rotor–stator homogenizer.
In summary, the rotor–stator homogenizer allows us to generate shear rates that are 1–2 orders of magnitude higher than in normal stirrer vessel equipment.
The Influence of Mixing in the Process
New methodology using VisiMix software for the purpose of checking the influence of mixing in the processes.
VisiMix Demo Operation
Learning how to input data into the VisiMix software and get results the will help us understand the influence of mixing in our processes.
Learning how to set up the relevant experiments at the lab scale, to develop the processes from an engineering point of view.