Introduction
Counter-centrifugal elements refer to the use of centrifugal force or the transfer of energy by centrifugal power to separate suspended medium particles, in order to form a transition between the convection and sedimentation processes. Counter centrifugation introduces concepts that focus on aggregating the small particles together, while larger particles are removed in the same direction. This process is used in many industries to separate fluids, suspensions, gases, and complex substances.
History
At the University of Utrecht in the Netherlands, the use of counter-centrifugal force to separate particles was first described in 1940 by professor Hendrik M. Benders. This technique was unique in that it used two volume tanks to control the velocity and density of the particles, allowing for more efficient and consistent particle separations. The idea of counter centrifugation was originally used to separate biological cells from larger particles and grew to be widely used in a variety of industries.
Application
Counter centrifugation is used for a wide variety of applications. In the papermaking industry, it is used to separate large wood fibres from fillers and smaller particles. In food processing, it is used to separate proteins and other components from liquids and slurries. In the pharmaceutical industry, it is used to separate proteins, drugs, and other analytical components. Counter centrifugal elements are also used in the mineral processing industry, to separate particles by density.
Process
Counter centrifugation is a relatively simple process consisting of three stages. In the first stage, the particles or material of interest is put into a tank where centrifugal forces are applied. The particles are then collected in a second tank or settling chamber where the velocity is reduced and the concentration of particles is increased. Finally, in the third stage, the concentrated targets are removed from the system with a retention aid to prevent them from entering the rest of the process.
Advantages
Counter centrifugation offers numerous advantages when compared to traditional separation methods. It is a more efficient process, with higher yields, and lower operating costs than sedimentation. Additionally, it produces more consistent particle sizes than traditional separation methods. Counter centrifugation also uses less energy than conventional centrifugal separators, and can be used to process a wide range of sizes and shapes of particles.
Disadvantages
While counter centrifugation is an efficient and cost effective method, it is not without its drawbacks. Depending on the type of system used and the size and shape of the particles, high amounts of energy can be needed to achieve stable operations. Additionally, counter centrifugal elements require a larger system size than conventional separators, making them less suited for applications which require a compact design.
Conclusion
Counter centrifugation has a wide variety of use, from the paper and food industries to mineral processing and even to the pharmaceuticals industry. This process offers numerous advantages when compared to traditional sedimentation methods, including increased efficiency, higher yields, and lower operating costs. However, it is not without its drawbacks, as it requires a large system size and high amounts of energy to achieve stable operations. Despite these drawbacks, counter centrifugation is an invaluable process that has revolutionized many industries.
