The Lyophilization Equipment of products are carried out in certain equipment, which is called vacuum freeze-drying machine, or freeze-drying equipment for short.

Freeze-drying equipment is divided into four main parts: refrigeration system, vacuum system, heating system and control system. According to the structure, it consists of freeze-drying box or drying box, condenser or water vapor condenser, refrigerator, vacuum pump and valve, electrical control element, etc.

The freeze-drying box is a high and low temperature box capable of cooling to about -40℃ and heating to about +50℃, and is also a closed container capable of vacuumizing. It is the first part of the freeze-drying equipment. The products to be freeze-dried are placed on the layered metal plate layer in the box, and the products are frozen and heated under vacuum to make the water in the products travel and dry.

The condenser is also a vacuum sealed container, which has a metal adsorption surface with a large surface area inside. The temperature of the adsorption surface can be reduced to below -40℃, and the low temperature can be stably maintained. The function of the condenser is to freeze and adsorb the water vapor from the products in the freeze-drying box on its metal surface.

The freeze-drying box, condenser, vacuum pipeline and valve, plus vacuum pump, form the vacuum system of freeze-drying equipment. Vacuum system requires no air leakage. Vacuum pump is an important part of vacuum system. The vacuum system is necessary for the product to move freely and dry.

The refrigeration system consists of a refrigerator, a freeze-drying box, pipelines inside the condenser, etc. Two sets of freezers can be independent of each other and one set can be used together. The function of the freezer is to refrigerate the freeze-drying box and condenser to break out and maintain the low temperature required for their operation. There are two methods of direct refrigeration and direct refrigeration.

The heating system has different heating methods for different freeze-drying equipment. Some use direct electric heating method; Some use the central medium for heating, and a pump keeps the central medium circulating. The effect of the heating system is to heat the products in the freeze-drying box, so that the water in the products can continuously travel and reach the regular residual water requirement.

The control system consists of various control switches, indication conditioning surfaces and some automatic equipment. It can be simple and messy. Generally, the control system of freeze-drying equipment with high degree of automation is messy. The function of the control system is to manually or automatically control the freeze-drying equipment and operate the machine to operate normally to freeze-dry products that meet the requirements.

The freeze-drying procedure of the Freeze Dried Fruit Machine is as follows: before freeze-drying, the products to be freeze-dried are packed in suitable containers, usually glass bottles or ampoules, with uniform loading, with the evaporation surface as large as possible and the thickness as thin as possible; And then put into a metal plate suitable for the freeze-drying box standard. Before packing, the freeze-drying box shall be cooled in an empty box, and then the products shall be put into the freeze-drying box for pre-freezing. Before vacuumizing, the condenser shall be operated in advance according to the cooling speed of the condenser freezer. During vacuumizing, the condenser shall reach a temperature of about -40℃, and the products in the box can be heated after the vacuum degree reaches a certain value (generally, it shall reach a vacuum degree above 100uHg). Generally, heating is carried out in two steps. The first step does not make the temperature of the product exceed the temperature of the eutectic point. After the water content in the product is completely dried, the second step of heating is carried out, at which time the regular maximum temperature of the product can be increased flexibly. Freeze drying can be finished after the maximum temperature is maintained for several hours.

The whole drying time is about 12-24 hours, which is related to the quantity of products in each bottle, the total assembly quantity, the shape and standard of glass containers, the variety of products, the freeze-drying curve and the function of the machine, etc.

After the freeze-drying is finished, dry sterile air should be put into the drying oven, and then plugged and sealed as soon as possible to prevent absorption of water from the air.

In the freeze-drying process, the temperature of the product and the plate, the condenser temperature and the vacuum degree are compared and plotted into curves, which are called freeze-drying curves. Generally, temperature is taken as the ordinate and time is taken as the abscissa. Different freeze-drying curves are selected for different products. When different freeze-drying curves are used for the same product, the product quality is also different, and the freeze-drying curve is also related to the function of freeze-drying equipment. Therefore, different products and different freeze-drying equipment use different freeze-drying curves.