Definition
A laboratory high-speed centrifuge is an instrument and equipment that uses the centrifugal force field generated by high-speed rotation to separate, concentrate or purify suspended particles or components of different densities in mixed liquids. Its rotational speed can typically reach tens of thousands of revolutions per minute, making it suitable for a variety of non-medical sample preparation and analysis processes.
How it works:
High-speed centrifuges operate on the principle of centrifugal sedimentation. When the container containing the sample rotates at high speed around the central axis, the sample is subjected to an outward centrifugal force, the size of which can be described by the following formula:
F = mω²r
where F is the centrifugal force, m is the mass of the particle, ω is the angular velocity, and r is the radius of rotation. Under the action of centrifugal force, the denser components settle towards the bottom of the container, while the lower density components accumulate in the upper layers, resulting in separation.
Measurement method
The key parameters of the centrifuge mainly include the measurement of rotational speed and relative centrifugal force. The rotational speed is usually obtained by monitoring the rotation frequency of the shaft through photoelectric sensors or magnetoelectric sensors. The relative centrifugal force is calculated based on the rotational speed and radius of rotation, and is commonly expressed as a multiple of gravitational acceleration. Some equipment is equipped with a real-time monitoring system, which can dynamically display operating parameters. Sample separation is usually verified by subsequent analytical methods, such as spectroscopy or concentration determination.
Influencing factors
The separation effect is affected by a variety of factors. The rotational speed and running time directly determine the centrifugal force and the acting time. Sample characteristics such as particle size, density difference, and solution viscosity affect the sedimentation rate. Rotor type and vessel material are related to load distribution and corrosion resistance. The stability of the temperature control system prevents thermal denaturation of the sample. The installation levelness and dynamic balance of the equipment will also affect the smoothness and separation accuracy.
Applications:
Used in food safety testing for the extraction of food ingredients or the isolation of microorganisms. The field of environmental monitoring is used to separate suspended particles or sediments in water bodies. It is used in materials science research for nanomaterial fractionation or composite preparation. It is used in the chemical industry for catalyst recovery or product purification. The biotechnology field can be used for cell component separation, but the scope of application needs to be limited. Used in agricultural science for soil particle analysis or crop component extraction.
Key points of selection
When selecting a model, technical parameters and usage requirements should be comprehensively considered. The rotational speed and maximum relative centrifugal force need to meet the separation requirements of the target sample. The rotor type and capacity configuration should be adapted to the commonly used vessel size and sample volume. The temperature control range needs to cover the requirements of the experimental environment. Safety features include overspeed protection, door locking mechanisms and imbalance detection. The user-friendly design of the user interface affects the efficiency of use. Ease of maintenance and continuous availability of accessories are also important considerations for long-term operation.