Features Of Freeze Dryer

Features of freeze dryer

Advantages of freeze dryer:

* Many heat-sensitive substances will not be denatured or inactivated.

* When drying at low temperature, some volatile components in the material are lost very little.

* During the freeze-drying process, the growth of microorganisms and the action of enzymes cannot be carried out, so the original properties can be maintained.

* Because it is dried in a frozen state, the volume is almost unchanged, the original structure is maintained, and the concentration phenomenon does not occur.

* Since the water in the material exists in the form of ice crystals after pre-freezing, the dissolved substances of inorganic salts originally dissolved in water are evenly distributed in the material. During sublimation, the dissolved substances dissolved in water are precipitated, which avoids the phenomenon of surface hardening caused by the precipitation of inorganic salts carried by the internal moisture of the material to the surface in the general drying method.

* The dried material is loose and porous, showing a sponge-like shape. After adding water, it dissolves quickly and completely, and the original properties are restored almost immediately.

* Because the drying is carried out under vacuum, there is very little oxygen, so some easily oxidized substances are protected.

* Drying can exclude more than 95% to 99% of water, so that the dried product can be stored for a long time without deterioration.

* Because the material is in a frozen state and the temperature is very low, the temperature of the heat source for heating is not high, and a heater with normal temperature or low temperature can meet the requirements. If the freezing room and the drying room are separated, the drying room does not need to be insulated, and there will not be a lot of heat loss, so the use of heat energy is very economical.

Precautions for freeze dryer:

1. The sample should be kept frozen and cannot be "melted back".

The freezing point of most solvents is higher than -40℃, so the temperature of the freezing chamber is lower than -40℃ to keep the general samples in ice.

To ensure that the sample does not "reflow", the frozen sample can be made into small pieces less than 20 mm.

2. Poisonous or corrosive samples.

It is best not to use it for freeze-drying. If it is necessary, system maintenance is even more necessary, and a special filter must be ordered to protect the vacuum pump.

3. The vacuum pump oil must be kept clean.