The experimental freezing spray dryer is an efficient separation equipment specially designed for laboratory scale. It is mainly used to transform liquid materials into dry powder through low-temperature atomization and rapid freezing. Its combination design achieves a gentle transition from liquid to solid, particularly suitable for the treatment of thermosensitive, easily oxidizable, or highly active substances. The following is the detailed composition structure and corresponding functional analysis of the device:

1、 Core component - spray system

The top of the equipment is equipped with a precision metering pump driven two fluid nozzle device, which can mix the liquid with compressed gas to form micrometer sized droplets. This dual channel design ensures the stability and uniformity of the atomization effect: the liquid material is transported along the central capillary tube, and high-speed airflow is introduced into the peripheral annular gap as a power source. When the two intersect at the outlet, a strong shear force is generated to break the liquid flow into small droplets, which then enter a low-temperature environment and begin the phase transition process. The system is equipped with an adjustable flow controller, allowing users to flexibly adjust the feed rate and air pressure parameters according to the characteristics of the sample, thereby accurately controlling the droplet size distribution.

2、 Experimental Cryogenic spray Dryer Low Temperature Cold Trap Device

The inner wall of the cylindrical vacuum chamber surrounding the spray area is inlaid with a semiconductor refrigeration chip array to form a quick freezing device. This module achieves rapid cooling through the Peltier effect, which can quickly reduce the temperature inside the chamber to below -50 ℃. This sharp temperature gradient causes the atomized tiny droplets to instantly solidify into solid ice crystal particles, effectively preventing the denaturation or degradation reactions of large molecular substances caused by heat. The inner wall of the cold trap is polished with a mirror finish to reduce material adhesion and facilitate observation of the experimental process. In addition, the design of the dynamic insulation layer ensures maximum energy utilization and reduces energy consumption costs.

3、 Vacuum subsystem

The two-stage vacuum acquisition system composed of a rotary vane mechanical pump and a diffusion pump in series is the key to maintaining a dry environment. The primary pump is responsible for extracting most of the air molecules and establishing a basic vacuum degree; The secondary pump further removes residual gas molecules, ultimately stabilizing the pressure inside the chamber at the level of 10 Pa. This ultra-high vacuum condition significantly reduces the triple point temperature of water, allowing the sublimation process to occur at lower temperatures. Real time monitoring instruments for vacuum degree, combined with automatic regulating valves, ensure that pressure fluctuations throughout the entire drying cycle are controlled within ± 5Pa range, ensuring repeatability between batches.

4、 Heating sublimation unit of experimental freezing spray dryer

The electric heating film heating plate located at the bottom of the equipment provides a controllable temperature rise curve, and evenly transfers heat to the load tray through the thermal oil circulation system. The program temperature control module supports multi-stage heating strategy settings, which can not only avoid the phenomenon of product sintering caused by sudden high temperature, but also ensure that ice crystals are fully sublimated without residual solvents. The infrared temperature sensor provides real-time feedback on the actual temperature of the material surface, forming a closed-loop control loop with the set value, with an accuracy of ± 0.5 ℃. This process simulates the principle of ice and snow melting in nature, but in a more controllable way.

5、 Collecting protective systems

A specially designed cyclone separator uses the principle of centrifugal force to separate light dry powder from exhaust gas, and heavier particles settle to the bottom of the collection bottle. Efficient HEPA filters intercept escaping fine dust and prevent it from entering the vacuum pump and causing wear. All parts in contact with the material are made of 316L stainless steel material, and the surface is treated with electrolytic polishing to eliminate the risk of metal ion contamination. The detachable structural design facilitates cleaning and disinfection, meeting GMP clean production requirements.

6、 Intelligent Control System of Experimental Refrigeration spray Dryer

The touch screen man-machine interface integrates all operation parameter setting functions, including time program control of key variables such as spray pressure, feeding speed, vacuum degree, heating rate, etc. The built-in history recording function can store up to hundreds of experimental plans, making it easy to quickly call them up for subsequent repeated experiments. The safety interlock mechanism monitors the operating status of each subsystem. Once an abnormal situation is detected (such as overheating, water outage, leakage), it immediately triggers an audible and visual alarm and automatically shuts down for protection. The network interface supports remote monitoring and data transmission, making it convenient for researchers to establish database management systems.