Introducing the principle of a fully open-lid centrifuge.

The principle of a fully open-lid centrifuge is that when a suspension containing fine particles is stationary, the suspended particles gradually sink due to gravity. Heavier particles sink faster, while particles with a density less than the liquid float. The speed of a particle in a gravitational field depends on its size, shape, and density, as well as the strength of the gravitational field and the viscosity of the liquid. Under normal gravity, particles the size of red blood cells, with diameters of a few micrometers, can be observed.Furthermore, when a substance settles in a medium, diffusion occurs. Diffusion is unconditional and inversely proportional to the mass of the diffusing substance; the smaller the particle, the more severe the diffusion. Settlement is relative and conditional, requiring external force. It is directly proportional to the weight of the settling object; the larger the particle, the faster the settling. For particles smaller than a few micrometers, such as viruses or proteins, which are in a colloidal or semi-colloidal state in solution, the sedimentation process cannot be observed by gravity alone. This is because smaller particles settle more slowly, and diffusion is more pronounced. Therefore, a fully open-lid centrifuge is needed to generate strong centrifugal force, forcing these particles to overcome diffusion and settle. Centrifugation utilizes the strong centrifugal force generated by the high-speed rotation of the centrifuge rotor to accelerate the settling velocity of particles in a liquid, separating substances with different sedimentation coefficients and buoyant densities in a sample.Precautions for using a fully open-lid centrifuge:1. To ensure safety and centrifugation efficiency, the instrument must be placed on a stable, level workbench, and no items should be placed on the engineering plastic lid. Samples should be placed symmetrically, and the nuts should be tightened before starting the machine.2. Before use, check the rotor for scratches, corrosion, etc. Also, check the centrifuge cups for cracks and aging. If any issues are found, stop using immediately and contact the manufacturer. Before starting the machine, always tighten the clamping nut on the rotor head to prevent the high-speed rotating head from flying off and causing an accident.3. The speed setting must not exceed the specified limits to ensure safe operation of the machine.4. If 0.00 or other numbers appear during use, and the machine does not run, turn off the power. It should restart after 10 seconds. After displaying the set speed, press the run button again, and the machine will run normally.5. If the specific gravity of the sample to be separated exceeds 1.2 g/cm³, the rotational speed N needs to be corrected according to the following formula: N = NMAX * (1.2 / sample specific gravity)¹/², where NMAX = rotor limit speed.6. Do not open the centrifuge lid when it is running with the lid fully open or when the rotor has not stopped to avoid accidents.7. Centrifuge cups must be filled with equal amounts of sample, and the rotor should not be allowed to run under unbalanced conditions.8. Each centrifuge run should not exceed 60 minutes.9. The centrifuge needs to be reliably grounded; unplug the power cord when the machine is not in use.

11-13-2025

Why Regularly Check the Ventilation Pipes of a Scraper Centrifuge?

When using a scraper centrifuge, the three key conditions for an accident are combustible material, oxidizer, and ignition source. The temperature of the material plays a crucial role in combustion and explosion.How can we prevent accidents? When using a scraper centrifuge, please pay attention to the following points to prevent accidents to a certain extent:1. Use inert gas or other gases to protect and control oxygen concentration. Flow monitoring and pressure monitoring methods can be used.2. Oxygen concentration can generally be strictly controlled using oxygen concentration monitoring methods. When using the above method, ensure a sufficient nitrogen source first.3. When using a scraper centrifuge, strictly follow the operating procedures, control the feed rate, and ensure uniform feeding. If uneven feeding is found, address it promptly to achieve uniformity. Regularly check the ventilation pipes on the scraper centrifuge to ensure they are unobstructed.4. Tighten the fastening bolts during installation.5. When using a liquid-liquid separator for liquid pressurization, strictly adhere to the operating procedures to prevent combustible gases from entering the machine.6. Strengthen equipment maintenance management, especially the corrosion prevention and maintenance of corrosive equipment. To prevent accidents during the use of scraper centrifuges, we must always keep these precautions in mind to protect our own safety and public property.When operating a scraper centrifuge, please note the following:1. If the electric scraper centrifuge makes noise or vibrates, immediately disconnect the power and troubleshoot the problem.2. After separation is complete, first turn off the scraper centrifuge. After the centrifuge stops rotating, open the lid and remove the sample. Do not force it to stop.3. Centrifugation time is generally 1-2 minutes. During this time, the experimenter must not leave to do other things.4. When starting the scraper centrifuge, first close the top lid, then start it slowly.5. Place a cotton cloth or test tube pad at the bottom of the centrifuge tubes.The above five points are precautions for using scraper centrifuges. It is particularly important to note that scraper centrifuges commonly used in laboratories are relatively fast. Before the experiment, the equipment must be carefully inspected to avoid accidents.

07-26-2024

Breaking Foreign Monopoly: The Rise of Domestic Centrifuges

As a pivotal product in water systems and the core technology of central air conditioning, centrifugal chillers significantly impact a company's operational revenue and brand image, making them an highly enticing "blue ocean."To break foreign monopolies, domestic brands have also embarked on the path of independent R&D in centrifugal chiller technology. What is the current market landscape, and how can companies navigate this space?Market Share Quietly Shifts: The Rise of Domestic Centrifugal ChillersIn China's HVAC market, the market share of centrifugal chillers is undergoing a transformation.In 2017, the five major American brands held 73% of the domestic centrifugal chiller market, while domestic brands, represented by Midea, accounted for only 11.6%.By the first half of 2021, the market share of foreign (joint venture) brands had dropped to approximately 69.4%, while domestic brands rose to about 30.6%. Among domestic brands, Midea led with a 26.1% market share.Over more than four years, the market share of domestic brands has doubled, while that of foreign brands has contracted. Midea, Gree, and Haier, the three major domestic brands, now hold the majority share in the centrifugal chiller market, positioning themselves as the new forces shaping its future. Their respective flagship products—Midea's High-Efficiency Direct-Driven Falling Film Centrifugal Chiller, Gree's Permanent Magnet Synchronous Frequency Conversion Centrifugal Chiller, and Haier's Magnetic Bearing Centrifugal Chiller—represent distinct technological paths and development directions.Behind these shifting numbers lies the fact that domestic centrifugal chiller brands are not only breaking the foreign monopoly but also advancing to higher levels.Hu Qimu, Chief Researcher at China Steel Economic Research Institute, stated in an interview with Securities Daily: "Currently, frequent policies in areas such as new infrastructure, dual carbon goals, and mass entrepreneurship and innovation are creating favorable conditions for domestic centrifugal chiller manufacturers. Simultaneously, they impose higher requirements in terms of energy savings, emission reductions, high-efficiency stable operation, and intelligent management."Advancing Independent R&D in Core Technologies to Gain InfluenceFrom the current industry landscape, competition in the central air conditioning market focuses on two areas: the residential retail market, representing the largest segment of fluorocarbon-based systems, and the centrifugal chiller market, representing the pinnacle of water chiller technology.In recent years, the central air conditioning market has developed rapidly. However, in the realm of large centrifugal water chillers, domestic brands started later and have less experience than foreign brands in R&D, operational models, and product manufacturing, resulting in a significant gap in market share. Companies seeking to expand their operations and enhance their brand stature have been hampered by the lack of centrifugal chiller technology, effectively leaving a critical aspect of their development in others' hands.In response to these challenges, domestic companies are accelerating independent R&D and strategic.A representative from Midea Building Technologies told Securities Daily that from independently designing and manufacturing China's first centrifugal water chiller in 1964 to delivering 1,000 centrifugal chillers in 2021 alone, Midea's nearly half-century journey in independent R&D has achieved progress from non-existence to existence, and from existence to excellence. This involved investments totaling billions of yuan.It is understood that in 2004, Midea jointly established Chongqing Midea General Refrigeration with Chongqing General Industry (Group), introducing all of CGI's compressor design, manufacturing, and testing technologies. Within two years, they launched a variable-frequency centrifugal water chiller, becoming the first domestic enterprise to do so. This broke the pattern of pure technology introduction and filled a national gap. In 2013, their products led the industry into the COP7 era.

11-29-2021