Centrifugation is to use the strong centrifugal force generated by the high-speed rotation of the centrifuge rotor to accelerate the sedimentation velocity of particles in the liquid, and to separate the sedimentation coefficient and buoyancy density of the sample. It is widely used in the industry engineering, playing a very important role.
Industrial centrifuge machine was born in Europe. For example, in the middle of the 19th century, three-legged centrifuges for textile dehydration and upper suspension centrifuges for separating crystalline sugar in sugar factories appeared successively. These earliest centrifuges were batch operated and manual slagging. Due to the improvement of the slag unloading mechanism, centrifuges that could operated continuously appeared in the 1930s, and the intermittent operation centrifuge was also developed due to the realization of automatic control.
According to the structure and separation requirements, industrial centrifuge types can be divided into three categories: centrifugal filter, sedimentation centrifuges and separators. A centrifuge has a cylinder, called rolling drum, that rotates around the axis at high speed and is usually driven by an electric motor. After the suspension (or emulsion) is added to the rolling drum, it is rapidly driven to rotate at the same speed as the drum, and the components are separated and discharged separately under the action of centrifugal force. In general, the higher the drum speed, the better the separation effect.
The working principle of industrial centrifuge machine has two kinds: centrifugal filtration and centrifugal sedimentation. Centrifugal filtration is to make the centrifugal pressure generated by the suspension under the centrifugal force field to act on the filter medium, so that the liquid passes through the filter medium to become filtrate while the solid particles are trapped on the surface of the filter medium, thereby realizing liquid and solid separation. Centrifugal sedimentation utilizes the principle of rapid sedimentation and stratification of components with different densities of suspensions (or emulsions) in a centrifugal force field to achieve liquid-solid (or liquid-liquid) separation. There is also another type of centrifuge separation equipment for experimental analysis, which can be used for liquid clarification and solid particle enrichment. This type of separator has different structural types operating under normal pressure, vacuum and freezing conditions.
It represents the ratio of the centrifugal force to the gravity of the material to be separated in the rolling drum. The larger the separation factor, the faster the separation and the better the separation effect. The separation factor of industrial centrifuge machine is generally 100 to 20,000, while the separation factor of ultra-speed tube separators can be as high as 62,000, and the separation factor of ultra-speed separators for analysis can be as high as 610,000. Another factor that determines the processing capacity of an industrial centrifuge machine is the working area of the rolling drum. The larger the working area, the greater the processing capacity.