One, the centrifuge tube centerline and the rotation axis angle is not the same: horizontal rotor at rest, the rotor in the centrifuge tube centerline parallel to the axis of rotation, rotational acceleration, the centerline from the parallel position of the gradual transition to the position of the rotation axis and the rotation axis close to perpendicular to the position of the descending speed, centrifugal tube centerline from the position close to perpendicular to the rotating axis gradually converge to the parallel position; angular rotor in the centrifugal tube centerline with the rotating axis into a fixed angle of 20 ~ 40 degrees, the greater the angle, the greater the separation effect. 40 degrees fixed angle, the larger the angle, the better the separation effect.
Second, the applicability is not the same: the horizontal rotor can do large-capacity separation and conducive to stratification from the centrifugal tube, should not be separated at high speeds; Angle rotor is not suitable for large-capacity separation, the particles settled, first along the direction of the centrifugal force into the centrifugal tube, and then along the wall of the tube sliding to the bottom of the tube, the tube will be a particle deposition on the side and the resulting wall effect, affecting the effect of separation, it is desirable to separate at high speeds.
Three, the center of gravity and resistance is not the same: horizontal rotor separation center of gravity is higher, resistance is greater, there is a small amount of wall effect; Angle rotor can be done with a low center of gravity, resistance is small, stable operation.
Expanded Information
The main principle of the filter centrifuge is that through the centrifugal force generated by the centrifugal drum of high-speed operation (with the appropriate filter material), the solid-liquid mixture of the liquid phase accelerated to throw out of the drum, and the solid phase will remain in the drum, to achieve the separation of solid and liquid. The liquid phase of the solid-liquid mixture is accelerated out of the drum by the centrifugal force generated by the high-speed rotating drum (together with the appropriate filter material), while the solid phase is left in the drum to achieve the effect of separating solids and liquids, or commonly known as the effect of dehydration. The main principle of sedimentation centrifuge is to accelerate the settling speed of different specific gravity components (solid phase or liquid phase) in the mixture through the powerful centrifugal force generated by the high-speed rotation of the rotor, so as to separate substances with different settling coefficients and buoyant densities in the samples.
When the suspension containing fine particles is standing still, the suspended particles gradually sink due to the effect of gravity field. The heavier the particle, the faster it sinks, and conversely particles that are less dense than the liquid float. The speed of particles moving under the gravity field is related to the size, shape and density of the particles, and is also related to the strength of the gravity field and the viscosity of the liquid. Particles the size of red blood cells, a few micrometers in diameter, can be observed settling under normal gravity.
Centrifuge tubes in angular rotors are capable of maintaining a fixed angle of centrifugation, allowing higher speeds to be used, with the post-centrifugation precipitate located on the beveled side of the tube bottom. Larger volume rotors can often be fitted with different "adapters" to "hold" smaller tubes, e.g. a 6 x 85 ml rotor can hold 85 ml centrifuge tubes per hole, 50 ml or 15-20 ml centrifuge tubes. For example, a 6 x 85 ml rotor can hold 85 ml tubes, 50 ml or 15 ml or 20 ml tubes in each hole, thus realizing multi-purpose use; however, due to the burden of weight, the maximum rotation speed of a large-capacity rotor is lower than that of a small-capacity rotor, and thus it is also necessary to consider whether the maximum centrifugal force is sufficient to satisfy the experimental requirements.
The horizontal rotor is equipped with 4 or 6 hanging baskets, which hang vertically on the rotor at rest, and the baskets have different adapters to meet the needs of centrifuge tubes of different capacities. When the rotor speed exceeds 600 rpm the tube reaches a horizontal position and the sample settles in the axial direction of the tube, finally settling at the bottom of the tube for easy collection. Because it is not as solid as a fixed angle rotor, the maximum speed of the horizontal basket is much lower compared to a fixed angle rotor and is limited to the range of low speed centrifugation.
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