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Preparation for the purchase of refrigerated high-speed centrifuges

2019/3/27 14:43:16      click :

  The premise of purchasing a refrigerated high-speed centrifuge is to have a detailed understanding of the centrifuge, first through the collection of data, followed by the consultation of the centrifuge manufacturer, a reliable refrigerated high-speed centrifuge manufacturer can bring you a bigger Benefits, today's Xiaobian is briefly summarized for everyone:
  The medical refrigerated high-speed centrifuge is a refrigerated centrifuge. The rotation speed is generally not more than 5000r/min. It can be used with a horizontal rotor and can meet the demand of large capacity. refrigerated high-speed centrifuges for laboratories such as schools and research institutes generally require refrigerated high-speed centrifuges (greater than 5000 r/min) and small-capacity angular rotors. When selecting a refrigerated high-speed centrifuge, the laboratory can select refrigerated high-speed centrifuges with different capacities, different rotation speeds and different temperature control according to the experimental purpose and experimental needs.
  For example, when it is necessary to use normal temperature, micro-time, and rapid centrifugation, a palm-type refrigerated high-speed centrifuge and a micro-refrigerated high-speed centrifuge can be used; if the rotation speed does not exceed 8000 r/min, for example, cells are collected during cell culture, an ordinary low-speed refrigerating centrifuge can be selected; If the required speed is greater than 12000 rpm, use a refrigerated high-speed centrifuge, such as small amount of plasmid DNA extraction, cDNA extraction experiments, protein extraction, competent preparation, and RNA extraction from plants, the rotation speed needs 12000rpm-15000rpm and maintain 4 degrees. In low temperature environments, frozen high speed refrigerated centrifuges can meet the requirements.
  When the refrigerated high-speed centrifuge rotates forward, the effect is to make the intracellular flow line close to the boundary direction. This is stable to the flow, so the temperature pulsation is reduced. When the second-hand refrigerated high-speed centrifuge is reversed, the role is to The vortex is pressed toward the center, which causes vortex, which makes the flow more unstable, and the temperature pulsation increases. During the crystal growth process, the impurity concentration in the crystal is related to the impurity concentration in the melt. It is effective and effective. The segregation coefficient is effective for the state of the melt flow in the boat. When the number is small, the number is large. The equilibrium segregation coefficient is a constant, is the crystal growth rate, and is the diffusion coefficient of the impurity in the melt. It is the boundary layer thickness. The temperature change in the melt near the growth interface directly affects the crystal growth rate, that is, the value affecting the arachnid. It also affects the concentration of impurities in the crystal. Obviously, the intense temperature pulsation will lead to uneven distribution of impurities in the crystal and impurity streaks. Therefore, the second-hand refrigerated high-speed centrifuge grows crystals when it is rotating, which will improve the crystal quality. When the refrigerated centrifuge is reversed, it is unfavorable for crystal growth. The results of this experiment provide us with a hint for crystal growth in a refrigerated high-speed centrifuge environment. In addition to being affected by overweight, it is also affected by force when it is performed on a refrigerated high-speed centrifuge. When horizontally oriented solidification grows a single crystal, if the direction of rotation of the second-hand refrigerated high-speed centrifuge is the same as the direction of heat convection in the melt, that is, when the high-temperature end of the melt is in the wind, the temperature pulsation in the melt can be suppressed, which is favorable for growth. The single crystal of the impurity stripe is reversed, if the high speed refrigerating centrifuge rotates in the reverse direction, that is, the low temperature end of the melt When the wind, the temperature of the melt in the presence of a strong pulsation, is not conducive to the growth of a uniform single crystal.
  When the refrigerated high-speed centrifuge does not rotate, as the temperature gradient increases, the temperature in the tin melt fluctuates from no pulsation to periodic pulsation, followed by irregular pulsation, and the amplitude increases significantly. When the temperature gradient is approximately, the pulsation amplitude is After the rotation of the second-hand refrigerated high-speed centrifuge, the two rotation modes of forward rotation and reversal are improved. The centrifugal acceleration is the acceleration of gravity, which enhances the convection in the melt and promotes the melt transfer. The heat mass transfer is carried out, the measured temperature gradient is reduced, but the temperature pulsation change trend is completely different. When the refrigerated high-speed centrifuge is rotating forward, a set of temperature pulsation curves is measured.
  The pulsation value greatly reduces the reversal of the refrigerated high-speed centrifuge, and the temperature pulsation curve is shown in the pulsation amplitude. Increase and increase, while the pulsation frequency also increases. At that time, the value is higher than that of the refrigerated high-speed centrifuge. Whether the refrigerated high-speed centrifuge rotates forward or reverse, the centrifugal force of the melt is the same for the same value. However, the force direction is opposite to the unit mass of the melt mass point. ,among them. It is the rotational angular velocity of the second-hand refrigerated high-speed centrifuge, which is the moving speed of the melt mass relative to the refrigerated high-speed centrifuge, angular velocity. The flow of the melt in the horizontal boat is mainly caused by the horizontal convection caused by the horizontal temperature difference, and the flow state is determined by the number. The eve is the volume expansion coefficient, which is the length of the boat. It is the coefficient of motion viscosity. When it is small, the melt flows. When it is large enough, a number of cellular circulations will occur, but the temperature of these cell-like flow furnaces remains. The same, the temperature pulsation recorded at different high speed refrigerating centrifuge speeds is forward rotation and is reversed.
  After reading the above analysis of the refrigerated high-speed centrifuge, I don't know if you have a detailed understanding of the centrifuge. For more information about the centrifuge, please visit the website of Shanghai Luxiangyi Centrifuge Instrument Co., Ltd. or call Shanghai Luxiangyi Centrifuge Co., Ltd. advisory!