K775X high vacuum freeze dryer

K775XHigh vacuum freeze dryer

If the water containing sample is naturally dried or dried in the air, the surface tension of the liquid will cause the sample to shrink and deform. One method to reduce deformation is to freeze dry the sample, which involves the principle of the three state equilibrium point in physics. Water has three states: solid, liquid, and gas. According to thermodynamic equilibrium theory, as the pressure decreases, the freezing point of water does not change much, while the boiling point decreases and approaches the freezing point. When the pressure drops to a certain degree of vacuum, the boiling point and freezing point of water coincide, and ice can vaporize directly into gas without going through a liquid state, a process called sublimation. The vacuum freeze-drying of samples is the process of sublimating and removing the pre frozen water in the sample below the triple point of water, i.e. under low temperature and low pressure conditions. The sublimation rate is a function of temperature and vacuum degree, and the typical drying time is several hours or longer. Freeze dryers are commonly used for pre drying of water samples under electron microscopes and similar applications.

K775XThe high vacuum freeze dryer can-100^oCThe following low-temperature work. The instrument is equipped with a turbo molecular pump, and its front stage pump is a rotary vacuum pump. Low temperature is achieved through the use of Dewar flasks and liquid nitrogen conduction cooling stages in the system, and can be maintained for several hours or longer by adding liquid nitrogen.

Pre frozen samples are loaded onto the cold stage of the drying chamber through a lid, using a sample transfer dedicated sample holder equipped with convenient "locking and positioning" loading tools for loadingTEMCarrier Network andSEMThere are two types of sample piles.K775XThe system integrates time and temperature control, and at the end of the drying cycle, the cold stage can heat the sample before removal. The system is also equipped with a nitrogen purging device.

Instrument features:

•Turbomolecular pumps are commonly used for vacuum extraction in important freeze-drying applications

•Liquid nitrogen conduction cold table can obtain-80Low temperature dry environment below ℃

•Programmable electronic control module, multifunctional automatic operation

•Accurate time and temperature monitoring, with a drying plan that can preset parameters such as drying temperature and drying cycle

Ideally, freeze-drying should be carried out at temperatures below the recrystallization point of ice, but this requires a long drying time. In practice, people have found that-60°CThe drying temperature (if used)15°CThe cooling circulating water device-Equipped with a heater/The cooler option can achieve acceptable drying results at vacuum levels achieved through a two-stage rotating mechanical vacuum pump. For such applications, please refer to:K750XPeltier semiconductor refrigeration freeze dryer. However, for certain fine samples, it is necessary to lower them below-80Dry at a lower sublimation rate at a temperature of ℃; This requires a better vacuum degree than using a rotary mechanical pump alone for vacuuming, as well as lower drying temperatures, such as liquid nitrogen temperature; For such applications, it is recommended to useK775XFreeze drying equipment.

In addition to freeze-drying machines, we also offer three critical point dryers: one with a vertical chamberK850Critical point dryer; Having a horizontal chamberE3100Critical point dryer; greaterK850WMThe critical point dryer is designed for semiconductor applications and can perform critical point drying6Inch wafers. These drying equipment products are specifically designed for scientific research purposes.