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The main factors that cause the rotor to be unbalanced during centrifugation

Sep 16, 2014

A centrifuge is a relatively complicated machine. The special equipment for rapidly separating the mixed solution by centrifugal force is to place a centrifuge tube, a bottle or a bag with a sample solution on a centrifugal shaft, and use the rotor. The powerful centrifugal force generated by the high-speed rotation around the shaft, which is a special device for separating particles of different nature from each other in the sample. The centrifuge has a cylinder that rotates rapidly about its own axis, called a drum, which is usually driven by a motor to allow sample analysis and separation.

According to the traditional theory, the centrifuge failure is caused by the excessive imbalance of the rotor, and the weighing error of the sample, the overflow of the centrifugal sample liquid during the centrifugation and the corrosion of the rotor are the main factors causing the rotor imbalance.

There are mainly the following reasons:

1. When the centrifuge tube is balanced, the balance of the centrifuge tube is more than 0.1 to 1 g due to the long-term use of the balance.

2. When the centrifuge tube is filled, the sample liquid bundle is filled or the centrifuge cap is not tightly sealed. During the centrifugation process, the high vacuum state in the centrifugal chamber causes the centrifuge tube to be flattened, broken, and the sample liquid overflows, causing the rotor to become unbalanced. Shaft bending or broken shaft accident.

3. Since the specific gravity of the original sample is not equal to the specific gravity of the trimming liquid, the rotor dynamic balance is out of balance and an accident occurs.

4. When using a horizontal rotor, the serial number of the bucket and the serial number of the horizontal rotor body are not carefully read, which affects the dynamic balance of the centrifuge rotor.

5. An aluminum alloy centrifugal cap is mixed with a stainless steel centrifuge cap (the two have different specific gravity) and an accident occurs.

6. The rubber seal ring and the rotor cap rubber seal ring in the centrifuge cap are improperly used and improperly disinfected, such as long-term use of internal fracture and solid high temperature disinfection r using dry box baking, etc., and the aging cracks, loss of sealing effect, etc., so that the sample is in Overflow at high speeds, allowing the rotor to operate in an unbalanced state.

7. For the centrifuge tubes of various materials, the use range and disinfection method of the centrifuge tube required by the manufacturer are not well understood before use, and the chemical solvent and the inappropriate disinfectant solution are used to cause the centrifuge tube to swell and rupture during operation. accident.

8. Carelessly in the work, the rotor cover is not tightened or the rotor cover and the rotor handle are interchanged, causing the screw to not match. When the machine is started, the rotor cover is thrown and a serious shaft breakage occurs.

The centrifuge is mainly used to separate the solid particles in the floating liquid from the liquid; or to separate two different density and incompatible liquids in the emulsion (such as separating the cream from the milk); it can also Used to remove liquids from wet solids, such as washing clothes with a washing machine; heterogeneous ultra-speed tube separators can also separate gas mixtures of different densities; solid particles with different density or particle size can be settled at different speeds in liquids. In some features, some sedimentation centrifuges can also classify solid particles by density or particle size.

Centrifuges are used more and more widely, and have received attention and pursuit from all walks of life.