Use four ringsDesktop freeze-dryingmachineWhen conducting experiments, you can refer to the following techniques and precautions to ensure the normal operation of the equipment and the effectiveness of the experiment:
Usage Tips
Familiarize yourself with the equipment manual: Before the first use, carefully read the product manual to understand the basic structure, working principle, and safety operating procedures of the equipment, which helps to use the equipment correctly and avoid operational errors.
Pre freezing operation: Start the cold trap and lower its temperature to the set value. For example, the cooling rate of the LGJ-12C vacuum freeze dryer in the fourth ring can reach 20 ℃ and drop to -40 ℃ ≤ 20 minutes. The temperature of the standard cold trap is usually lower than -62 ℃. During the pre cooling process, the temperature changes of the cold trap can be monitored in real time through the device display screen. When pre freezing the sample, ensure that it freezes into ice to avoid residual liquid causing gasification spray.
Loading materials: Spread the materials to be dried evenly on the shelves of the freeze dryer, taking care not to exceed the specified effective shelf area, leaving a certain gap between the materials to facilitate heat transfer and water evaporation.
Vacuum pumping and drying: Connect the vacuum pump, turn on the vacuum system, and extract the gas from the freeze-drying chamber to achieve the predetermined vacuum degree. The pumping rate should meet the requirement of reducing the standard atmospheric pressure to 5Pa ≤ 10 minutes. The material gradually completes the sublimation process in a low-temperature and low-pressure environment, during which the parameter settings can be adjusted according to the actual situation to optimize the drying effect.
Monitoring and recording: Using the built-in sensors and control system of the equipment, key parameters such as vacuum degree and cold trap temperature are monitored throughout the process, and freeze-drying curves are recorded for later data analysis.
End operation: After the material is completely dried, turn off the vacuum pump and refrigeration system, slowly open the intake valve, and restore the pressure in the freeze-drying chamber to normal level. Take out the dried materials and store them properly.
Precautions
Environmental conditions: Ensure that the power supply voltage meets the requirements of the equipment, and the ambient temperature should be within the allowable range of the equipment (usually not exceeding 30 ℃). At the same time, pay attention to maintaining good air circulation in the laboratory to avoid damage to equipment caused by humid environments.
Cleaning and sealing: Before use, thoroughly clean the inside and outside of the freeze-drying machine, especially the material placement area, to prevent impurities from contaminating the material. The sealing rings of the freeze-drying chamber and cold trap chamber should be kept clean, and should be cleaned promptly after each freeze-drying to avoid cross contamination of different materials. Organic glass doors should not be cleaned with organic solvents and should not come into direct contact with other hard objects to avoid damage and affect the vacuum degree.
Vacuum pump maintenance: Regularly check the quality of the pump oil. Generally, after working for about 800-1000 hours, the vacuum pump oil needs to be replaced once. If water enters the vacuum pump and oil emulsifies, please replace the vacuum pump oil in a timely manner.
Safe operation: The electrical control box contains AC380V power supply. Non professionals should not touch this part of the components to avoid the risk of electric shock. After changing the position of the AC380V power socket, please confirm whether the rotation direction of the vacuum pump is correct. If it is not correct, it is necessary to ask a professional electrician to adjust the phase line of the AC380V power supply. The four ring freeze dryer is equipped with a door lock, and the side panel can be opened after the lock is opened. Please keep the key and do not open the side panel by non professionals or maintenance personnel.
Materials and Operations: If there is no fixed procedure for freeze-drying new materials, contact the manufacturer in a timely manner for parameter adjustment. Four ring freeze-drying provides technical support. Due to the high temperature in summer, it is recommended to freeze dry 15 liters of material at full capacity and 20 liters in winter. Do not exceed the capacity to prevent water from entering the vacuum pump. When operating at low temperatures, pay attention to wearing cotton yarn antifreeze gloves to avoid frostbite. Especially when operating the pallet rack after pre freezing, be sure to wear cotton gloves. Do not frequently switch the refrigeration system during operation. If the compressor stops running due to operational errors or other reasons, wait for 15 minutes before restarting to avoid damaging the compressor.
Equipment inspection: Regularly clean the dust accumulation on the condenser of the refrigeration system to avoid affecting the heat dissipation effect and causing refrigeration failures. Check the refrigeration circuit for leaks and the operating status of each component every 6 months, and inspect the action of alarms, grounding, and door proximity switches.