Freeze Dryer

A freeze dryer or lyophiliser is a popular instrument for absorbing water from perishable materials and making them long-lived. This instrument is mainly utilised to extract water from materials and prepare them for long transportation.

How a freeze dryer works:

Freeze dryer first freezes the material, with temperature reduction the pressure is also reduced within the material. In this period the freeze dryer provides heat to evaporate internal water molecules.

Freeze freeze-dryer instrument works in three phases. These phases are freezing, primary drying or sublimation, and secondary drying or absorption. Now here are the details about these three phases of the Freeze dryer.

Freezing: In this crucial phase of freezing, there is either a chilled bath or a shelf for freezing. With a slow freezing or annealing process, ice crystals are developed. During this crystallisation phase, freezing is done very quickly to protect cell-rupture or other biological changes of the material. To get the best result, mostly we use the annealing process for a quick freezing process. During this freezing process, we should be cautious about the tripling point of the material, otherwise the material will be melted instead of being sublimated.

Primary drying:

In this phase, heat is provided with reduced pressure. The cold condenser of the freeze dryer helps to extract the water and make a solid surface with a sublimation process. To achieve the best result, we should make this step slow and protect the material from melting.

Secondary drying:

The last phase, the secondary drying is the step where the material is heated to remove ionically bonded water molecules. For the high temperature, bonds between the water molecules and materials get removed. When the water is evaporated then the material is sealed and then the vacuum is broken.

These are the steps for successful freeze-drying of materials to enhance their longevity.

What should we avoid during freeze-drying?

During freeze-drying, we should not heat too much. The material may be melted up or collapsed.

The condenser should be protected from over-vapourization during freeze-drying.

We should not create too much vapour.

Sufficient surface area is very necessary during freeze-drying the material.

Before processing a material we should refrigerate the material properly.

Utilisation of the freeze-dryer: 

Pharmaceutical industry:  In the pharmaceutical industry and medicine preparation sector, freeze-dryer is highly utilized to preserve costly drugs, medicines, various kinds of vaccines etc. It helps to store medicines with its efficiency and utility with a long life.

Food preparation industry: In the food preparation industry, a freeze-dryer is utilized to store fruits, costly vegetables, cereals, and ready-to-serve foods and beverages in a dehydrated condition. With this instrument, all of these are preserved for a long time without compromising the nutritional value, delicious taste and natural textures. 

Biotechnological industry: In the biotechnological industry, scientists or students use this instrument to preserve enzymes, vitamins, bacterial culture etc in dehydrated conditions. With the help of this instrument, biotechnology engineers can use these samples for a long time with maintained viability.

Chemical preparation: Freeze-dryer or lyophilizer is also popular in the chemical preparation industry to store chemicals, lab reagents and others for a long time without any degradation in reactivity.

Cosmetics preparation & preservation: In cosmetics shops or industry, a freeze dryer is utilized to make those long-stayed and stable-textured.

Many people utilize the freeze-dryer to keep their books and documents moisture-free. With this instrument, you can store all perishable material normally at room temperature. With dry freezing machine, all materials become dehydrate and with a long-time shelf life.