A freeze dryer is one of the most common and essential drying equipment, which is used to dry items by utilizing the freeze drying technology. It usually consists of four components, including a drying chamber, a vacuum pump, a heat source and a condenser.
How does a Freeze Dryer work?
The working process of a freeze dryer can be simply described as follows. It can pre-freeze materials that need to be dried in order to make materials in the solid form. Making use of the direct sublimation property of ice, it can dehydrate materials and dry them into powder under conditions of low temperature and low pressure.
Specifically speaking, the working of a freeze dryer can be classified into three periods. The first period is the freezing, which can preserve the physical form of materials. The second period is the primary drying or sublimation, which reduces pressure and heats materials to sublimate water. Primary drying may be a slow process, but approximately 95% of water in materials is removed at this stage. The third period is the secondary drying or absorption, during which the ionically-bound water molecules are removed. The complete working process is finished. Most materials can be dried to 1-5% residual moisture.
Applications of a Freeze Dryer
As one of the types of necessary drying equipment, the freeze dryer can be widely used in biological, chemical and pharmaceutical fields. It is usually used to dry heat sensitive materials that are thermally unstable and easy to oxidize and deteriorate, as well as the materials that are unstable in aqueous solutions and need to maintain biological activity.
Does Freeze Drying Kill Bacteria?
It’s known that the freeze drying is a water removal process which is primarily used for preserving perishable materials or making them more convenient for transport. Research indicates that the freeze drying can decrease the number of bacteria to a certain extent, but can’t kill all of bacteria. Some bacteria will go into a dormant state and still stay alive in the frozen materials. When the environment becomes favorable, bacteria will return to a normal state.
Does Freeze Drying Remove Water?
As we talked above, freeze drying is to freeze materials into solid-phase firstly and then sublimate water within these solid materials directly into vapor. So in this process, water within materials get into ice and then gas. And finally water within materials get out of the materials as vapor. Therefore, freeze drying removes water in this way.
How Long does Freeze Drying Take?
Many people wonder “how long does freeze drying take”? The answer is “it depends”. Now let me tell you the reason. The time that freeze drying takes varies because of the different applications and conditions of freeze drying. Generally, it takes one day or two days for freeze drying to work. Freeze drying mostly takes one day or two days and there are still some exceptional examples.
What is the Difference between Freeze Drying and Lyophilization?
Freeze drying and Lyophilization are very similar but there are still some differences here between the two. They both are methods that is to freeze materials into solid-phase and then sublimate water within them into gas-phase directly under vacuum. Freeze drying and Lyophilization can be different from each other when they are in different industrial situations and venues.
Types of Drying Machine
Drying machine is widely used in many fields, for example, industrial field, chemical field, drying food machine for home use, drinking field, petroleum and chemical industry field, oil and fat industry field, synthetic fiber industry field, textile printing and dyeing work field, non-woven industry field and so on.
There are so many kinds of drying machine for using in different field, for example, food drying machine for people’s daily life, industrial drying machine for industrial usage, industrial air dryer, industrial hemp drying equipment, industrial freeze drying equipment, industrial food drying equipment, industrial paint drying equipment and so on.
Freeze Drying Food Machine for Home Use
Freeze drying food machine is quite popular at people’s daily life at home. Freeze drying food machine for home use is a small vacuum freeze dryer. It can be applied to the use at home and other use. It is widely used in the freeze drying of fruits, all kinds of meats, vegetables, herbs, health care and so on.
Freeze frying food machine is operated by people through touch screen buttons, and it can be automatic during the working process, which is very convenient and relaxing for people. It has an advanced system, small running current and it is energy-saving.
It has a food-level stainless steel 304 plate and inner design, which is very safe and guaranteed. Besides these practical characteristics, this machine still has a beautiful appearance and compact size.