Home > News > Content

Centrifuge Speed Is Determined By Many Factors

Oct 26, 2016

The use of centrifuges should not refer to the pursuit of speed, not to give priority to safety factors, secondly, to consider the inertial force of the centrifuge and the rotor, and finally to select the centrifuge for the separation of substances.

The centrifuge has a protection program. If you do not cover the cover, it will alarm. If you do not cover the inside of the cover, it will fly out. It will catch people and cause serious accidents. The rotor will also fly out, so today's centrifuges basically have automatic shutdown protection.

The price of the centrifuge is mainly reflected in the difference of the host. In terms of performance, the centrifuge with freezing is much more expensive than the ordinary one. Some centrifuges also have heating function. The more control programs, the higher the price of the centrifuge. The big difference is the configuration aspect, and sometimes the price of the attachment is often higher than the price of the host. When purchasing, be careful to select the rotor, in addition to the main unit, plus the necessary centrifuge tubes, sleeves, special centrifuge bottles or blood bags, all of which add up to the price of a complete centrifuge.

In a non-inertial system in which the centrifuge moves in a circular motion, the inertial force is always outward and there is no corresponding inward force. To maintain the object relatively stationary in the non-inertial system, other forces are needed to counteract this inertial force, such as the pulling force of the rope, the support of the outer wall, and the gravitation of a mass object. In fact, in all non-inertial systems, an inertial force can be fabricated according to the equivalent principle, the direction of which is opposite to the direction of acceleration of the non-inertial system (relative to the acceleration of the inertial system), and the magnitude is the acceleration multiplied by the mass of the object. This is done to facilitate the handling of the force balance in the non-inertial system, rather than who is actually applying such a force.

Because of the amazing speed of the centrifuge, the fixed rotor is not a normal ball bearing, but a magnetic suspension bearing. The magnetic suspension bearing uses a magnetic field to keep the rotor in the center of the stator coil. There is no physical contact between the rotor and the stator, which eliminates friction and ensures the stability of the ultra-high speed operation of the centrifuge.

The centrifuge vibrates during acceleration and deceleration because, in addition to resonance, I think that the change of center of gravity during acceleration and deceleration is also an aspect, which may be related to resonance. When the vibration frequency and the natural frequency of the material are close to each other, resonance occurs. According to the vibration theory. A solid object actually has an infinite number of natural frequencies. When the external excitation frequency is consistent with the natural frequency of the object, resonance occurs. At this time, the amplitude of the vibration is particularly large (amplitude). This phenomenon is usually Harmful. As for the trimming problem, it is a problem of dynamic balance. It is because the center of mass of the object does not coincide with the center of rotation and the eccentricity occurs. The vibration is also induced, which belongs to the category of vibration theory. Personally think that it is the above phenomenon caused by resonance. Of course, there may be no trim.

If you get the organelles, you should go to a special ultra-centrifuge. In a certain range, you can shorten the operation time by extending the time. But not all of them can be dried. The kind of strict balance and centrifugation before the washing machine is put in. The cups are all specially made, and it is said that they will also be vacuumed before centrifugation.

Centrifuge rotor replacement is also a technical activity. Wipe the centrifuge chamber with a clean soft cloth to ensure that there is no foreign matter in the centrifuge chamber. Wipe the inner rotor seat and the inner hole of the rotor with a clean soft cloth and apply a thin layer of grease. Lift the angle rotor with both hands and gently put it into the rotor seat of the centrifugal chamber, and screw the compression nut into the compaction. Special tools for tightening nuts must be taken out and must not be operated at random. Remove the entire rotor body from the centrifuge, unscrew the rotor cover, loosen the tightened nut with a special tool, and then use the special handle of the centrifuge rotor to screw the center hole of the angle rotor to loosen the entire rotor. The horn rotor body takes the entire rotor out of the centrifuge chamber. Note: When removing the rotor, it should be taken up vertically. It is forbidden to pull the rotor body hard to avoid damage to the rotor seat.