Freeze dryer composition
The freeze dryer is divided into systems, consisting of six main parts: refrigeration system, vacuum system, heating system, circulation system, plugging system and control system. According to the structure, it is composed of freeze-drying box or drying box, cold trap or water vapor condenser, refrigeration unit, vacuum unit and valve, hydraulic unit, circulation unit, electrical control components, etc.
The function of the freeze-drying box: the freeze-drying box is the main part of the freeze-drying machine. The products that need to be freeze-dried are placed on the layered metal plates in the box to freeze the products and heat them under vacuum to make the products The moisture sublimates and dries.
As a vacuum tight container, the cold trap has a metal adsorption surface with a large surface area inside it. The temperature of the adsorption surface can be lowered to below -40℃～-70℃ and can maintain this low temperature range. The function of the cold trap is to freeze and adsorb the water vapor sublimated from the products in the freeze-drying box on its metal surface.
Vacuum pump, etc. constitute the vacuum system of the freeze dryer. The vacuum system requires a strict vacuum leakage rate, and the vacuum pump is an important part of the vacuum system to establish vacuum. The vacuum system is essential for the rapid sublimation and drying of products.
The refrigeration system is composed of a refrigeration unit, a freeze-drying box, and a pipe inside the cold trap. The refrigerator can be two or more independent sets, or one set can be used together. The function of the refrigerator is to refrigerate the freeze-drying box and the cold trap to generate and maintain the low temperature required for their work. It has two methods of direct refrigeration and indirect refrigeration.
The heating system has different heating methods for different freeze dryers. Some use the direct electric heating method; some use the intermediate medium for heating, and the intermediate medium is continuously circulated by a pump (or a backup pump). The function of the heating system is to heat the products in the freeze-drying box so that the moisture in the products is continuously sublimated and reaches the required residual moisture content. KZG-30 adopts intermediate medium for heating, that is, it adopts circulation system for indirect heating. Its circulation system adopts international famous brand circulation pump set, which has fast circulation speed.
The control system is composed of various control switches, indicating and regulating instruments and some automatic devices. It can be simple or complex. Generally, freeze dryers with a higher degree of automation have more complicated control systems. The function of the control system is to manually or automatically control the freeze dryer, and manipulate the machine to operate normally, so that the freeze dryer produces products that meet the requirements. KZG-30 adopts PLC+touch screen, PLC+workstation or PLC+touch screen+workstation mode.
