Core Design of Key Components for Centrifuges

　　 Centrifuge It includes 12 programmable program modes and 10 acceleration/deceleration steps. In each program mode, you can store different settings for timing duration, rotational speed, centrifugal force, acceleration steps, and deceleration steps, allowing users to program various modes according to their needs for later recall and use. If you wish to change the program mode, simply press the “Mode Setting” button once. The “Program Mode” window will start flashing, indicating the currently selected program mode. Use the numeric keys to modify the setting until you reach the desired mode, then press the “Confirm” button to activate that mode. If you want to modify any of the settings within a specific program mode, press the “Mode Setting” button twice in quick succession. The “Timing” window will then start flashing. Refer to sections 5.3.2.1 through 5.3.2.3 to adjust the “Timing,” “Rotational Speed,” and “Centrifugal Force” settings accordingly. Once you have finished modifying the centrifuge’s centrifugal force parameters, press the “Confirm” button again. The “Acceleration Step” window will then start flashing, displaying the current acceleration step setting for this program mode. Use the numeric keys to modify the acceleration step, and after confirming with the “Confirm” button, the “Centrifugal Force” window will begin flashing. Adjust the centrifugal force using the numeric keys, and after confirming with the “Confirm” button, the “Deceleration Step” window will start flashing, showing the current deceleration step setting for this program mode. Use the numeric keys to modify the deceleration step, and after confirming with the “Confirm” button, the programming or modification process will be completed. All modifications and settings made above will be saved in the current program mode.
　　During high-speed rotation, the motion induced by centrifugal force causes solid particles suspended in a liquid to settle out—specifically, particles with greater mass or volume in the suspension move toward the region of the rotor with the greatest radius, while particles with smaller mass or volume tend to deposit closer to the rotor’s inner radius. A centrifuge is a machine that generates centrifugal force, which depends on the rotor’s radius, rotational speed, and sample mass: F = Rmω² (where F is the centrifugal force, R is the radius, m is the sample mass, and ω is the rotational speed). Centrifugal force is one of the most important parameters for measuring performance and also serves as a key criterion for distinguishing between different equipment grades; manufacturers typically provide this value when the centrifuge leaves the factory. Centrifuge the maximum rotational speed and the centrifugal force. As we all know, the radius of the rotor and the mass of the sample remain constant during operation; only the rotational speed can be varied through control. Therefore, we often tend to use rotational speed as a way to describe a centrifuge.

　　The rotor of a centrifuge is one of its key components. On the one hand, the rotor’s structure has a decisive impact on the machine’s intended application, operation, production capacity, and power output. On the other hand, due to its high-speed rotation—typically ranging from several hundred to tens of thousands of revolutions per minute—the centrifuge rotor itself is subjected to centrifugal forces. Under these centrifugal forces, significant working stresses develop within the rotor body. Once the rotor’s strength is compromised, it can lead to severe hazards, especially when excessive stress causes “fracture” or “bursting,” often resulting in serious personal injury accidents. At the same time, for high-speed rotating centrifuge rotors, the rotor’s stiffness is equally critical. If the rotor lacks sufficient stiffness, its geometric shape will undergo noticeable changes during operation. In mild cases, this may cause the rotor to collide with or rub against the machine casing, damaging components; in severe cases, it could also lead to rotor rupture and even result in personal injury accidents. Over the years, major accidents caused by improper rotor design and poor manufacturing quality have occurred repeatedly, prompting increased attention from designers, manufacturers, and users. As a result, diagnostic, analytical, and research efforts into the causes of accidents involving three-legged centrifuges have become commonplace. Therefore, conducting thorough analyses and studies on rotor design calculations is highly necessary.
　　The formula for calculating the wall thickness of a centrifuge rotor drum originates from the design codes for thin-walled pressure vessels—that is, the rotor drum is treated as a thin-walled shell subjected to internal pressure, and its strength is verified based on the theory of no-moment shells. However, existing rotor drum design methods do not take into account the minimum wall thickness required; instead, they treat strength requirements as both necessary and sufficient conditions. This practice is actually inappropriate. Over the years, pressure vessel design codes have always specified a minimum wall thickness for vessels, with the fundamental purpose being to ensure that the vessel possesses adequate rigidity, thereby preventing geometric distortions (such as loss of circularity in cross-sections). Once such distortions occur, the bending stresses experienced by the vessel will far exceed the membrane stresses used as the basis for wall thickness calculations. This clearly demonstrates that the strength condition in rotor drum design is necessary but not necessarily sufficient. A centrifuge rotor drum is a thin-walled component rotating at high speed; the aerodynamic forces it experiences are comparable to those acting on a stationary thin shell exposed to strong winds. Structures located in random turbulent flow fields will invariably undergo vibration, and the rotor drum is naturally no exception. Once the excitation frequency coincides with or closely approaches the rotor drum’s natural frequency, its geometry will undergo significant changes, with potentially catastrophic consequences. Therefore, it is highly essential to consider rigidity requirements when designing rotor drums. Failing to take rigidity requirements into account during design is... Centrifuge One of the reasons for the drum bursting accident.