Laboratory centrifuge structure

General laboratory centrifuges are basically the same in structure as high-speed centrifuges, mainly including four main parts: drive, various rotors, temperature control (low-temperature models), and whole machine control.
Drive system
The use of brushless variable frequency motors to replace DC series motors is a revolution in the history of centrifugal technology. The advantages that come with it are:
(1) It can output maximum torque at different speeds, which provides an important premise for the development of a multifunctional general centrifuge;
(2) Easy maintenance. DC series motors require regular replacement of carbon brushes (usually every 100 to 1000 hours), which brings a lot of inconvenience to users. The maintenance of the drive part using variable frequency motors is mainly to replace bearings, and the cycle is extended;
(3) Low noise, eliminating the high-frequency noise generated by carbon brush friction. When running at 15000r/min, it can be controlled below 65dB and does not need to be installed in a special room; and because there is no carbon powder pollution, it can also be used in sterile and dust-free laboratories with specific sample separation requirements;
(4) Fast starting speed;
(5) Electronic imbalance detection;
(6) The overall size, weight and power consumption of the machine are reduced, so most of them are made into desktop models.
Centrifugal rotors
Rotors of different forms and technical performances represent centrifugal functions, which can be summarized as follows:
(1) High-speed rotors are mostly made of aluminum alloy, optimized by computer three-dimensional calculation, and have the advantages of light weight and high speed;
(2) High-speed rotors are made of carbon fiber, with large capacity, light weight and strong corrosion resistance;
(3) The development of high centrifugal force rotors has shortened the separation time of some difficult-to-separate biological samples, reduced concentration diffusion, and improved separation purity and resolution;
(4) Angle rotors adopt a small inclination design, which has the advantages of small sedimentation distance, large longitudinal section area and short separation time of vertical rotors, and are especially suitable for plasmid DNA and RNA separation.
Temperature control system
General laboratory centrifuges are available in two types: low-temperature control and normal temperature, but models exceeding 18,000 r/min are mostly low-temperature control. Low-temperature control is mostly a first-stage compressor without fluorine refrigeration, and the temperature control range is generally -9℃～-40℃ or -20℃～40℃, with an accuracy of ≤1℃. It has a pre-cooling program and a constant cooling function in standby mode to meet the laboratory's mobility and continuous work needs. [2]
Control and display
Mostly adopt microprocessor control, digital or LCD screen display control panel, and key human-machine intelligent adjustment. This makes this type of centrifuge have some important control features:
(1) Automatic rotor recognition;
(2) RPM and RCF can be set, and the actual value can be displayed in real time, reducing the trouble of calculation;
(3) Multi-speed setting speed increase/deceleration control;
(4) Instant centrifugation (Shon-run) control;
(5) Program memory and storage function, which can store multiple centrifugation programs (up to 20) commonly used by the laboratory (user), so as to facilitate the call-up of a previously used optimized program for centrifugation operation;
(6) Self-test and fault prompts.
These features will be beneficial to laboratory instrument management.
Safety protection
Having self-protection measures is very important for the safe operation of the centrifuge, such as: automatic cover locking, over-temperature, over-speed, imbalance protection, etc., and a prompt sound alarm will be issued in the event of an erroneous operation.