Freeze dryer is a device that uses a complex and precise process to dry sensitive and biological materials while preserving their properties. This device is used in various industries such as pharmaceutical, food, biotechnology, agriculture, etc. On this page, we introduce, use, types, advantages and disadvantages of freeze dryer.

Introduction of Freeze Dryer

What is a freeze dryer? Freeze-drying or lyophilization is a drying method in which the material is first frozen and then subjected to low pressure and the solvent (usually water) is sublimated from it. This method preserves the structure and properties of the material and increases its shelf life. The freeze-drying process consists of three main steps:

• Freezing: In this step, the material is cooled to a suitable temperature (usually below the triple point) and is frozen solid.
• Sublimation: In this step, the pressure is reduced and heat is given to the material so that the solvent (water) turns from a solid state into a vapor and leaves the surface of the material.
• Secondary drying: In this stage, the temperature is higher and the pressure is lower, and the remaining solvent in the depth of the material is sublimated and removed.

Application of Freeze Dryer

Freeze dryer is used in various industries, including the following:

• Pharmaceutical industry: Freeze-drying process is used to dry heat-sensitive drugs, vaccines, antibodies, proteins, bacteria, fungi, blood and other clinical products. This method makes the drugs portable and stored and their performance does not change.
• Food industry: Freeze drying process is used to dry food such as fruits, vegetables, coffee, tea, milk, eggs, etc. This method causes the food to have less weight and volume, and preserves its color, taste, smell, vitamin and nutrient content.
• Biotechnology industry: Freeze drying process is used to dry biological materials such as DNA, RNA, enzymes, cells, tissues, etc. This method makes biological materials maintain their biological activity and can be stored and used.
• Agricultural industry: Freeze-drying process is used to dry seeds, flowers, medicinal plants, etc. This method allows the seeds to germinate and the flowers and medicinal plants maintain their ornamental and therapeutic properties.

Freeze Dryer types

Based on the operation and general structure of freeze dryer devices, they can be divided into three general groups, which are:

• Shelf freeze dryer: This type of freeze dryer includes several shelves, each shelf has heating lights. The dryable material is spread as a thin layer on the shelves and placed under vacuum. This type of freeze dryer is suitable for drying powder products, tubes, breakable containers, etc.
• Rotary freeze dryer: This type of freeze dryer includes several rotating surfaces, each surface has heating lights. The dryable material is spread as a thin layer on the rotating surface and placed under vacuum. This type of freeze dryer is suitable for drying powder products, tubes, breakable containers, etc.
• Turbine freeze dryer: This type of freeze dryer includes several turbines, each turbine has heating coils. The dryable material is pumped into the turbine as a spray and placed under vacuum. This type of freeze dryer is suitable for drying powder products, tubes, capsules, emulsions, suspensions, etc.