How to deal with the dehumidification effect of the four-ring lyophilization experimental lyophilizer is not good

The substance containing a large amount of moisture or other solvents, pre-cooled and frozen into a solid, and then under certain vacuum conditions, so that the moisture or other solvent in it is directly sublimated from the solid in the form of vapor, and the substance itself remains in the ice shelf when frozen, the dried material is the same volume as before drying but loose and porous, and has good rehydration, this drying method is called freeze-drying method, and the equipment for this operation is called a freeze dryer
.

Vacuum freeze-drying is a process of liquid→ solid→ gaseous state
.

During the lyophilization process, the "liquid bridge" between the solute particles has been frozen into a "solid bridge", the relative position between the two particles has been fixed, and there is no surface tension
at the gas-liquid interface between the two particles.

With the continuous sublimation of the solvent, the "solid bridge" continues to decrease, but the relative position between the two particles no longer changes, until the "solid bridge" disappears
completely.

The four-ring lyophilization experimental lyophilizer is mainly composed of control system, vacuum system, refrigeration system and circulation system; There are also hydraulic systems, in-place cleaning systems and in-place sterilization systems
.

In the process of compressing the air in the four-ring lyophilization experimental lyophilizer, by reducing the freeze-drying temperature of the compressed air, when the temperature continues to decrease, we can let all the moisture in the compressed air precipitate
.

In fact, the freeze-drying principle of the lyophilizer and the source flow of the household refrigerator are almost the same as when the compressed air passes through the compressed air pipeline, the compressed air drops, so as to meet the drying requirements
.

Why is the dehumidification effect of the lyophilizer poor? How to deal with it? 1.
The inlet pressure is too low, the ambient temperature is too high, the processing air volume is too large, and the inlet temperature is too high; 2.
The air bypass valve is not closed; 3.
Automatic drainage system failure: (1) The shut-off valve before the drain is not opened; (2) The drain is blocked or damaged; (3) The air pressure is less than 0.
6MPa; (4) the drain pipe is higher than the drain.


The treatment measures are as follows: 1.
The working conditions should meet the requirements of the nameplate or re-select the dryer; 2.
close the air bypass valve tightly; 3.
open the globe valve, clean and replace the drain, the air pressure shall not be less than 0.
6MPa, and the drain should be reinstalled
.