In the laboratory material drying experiment, the laboratory low-temperature spray dryer is widely used in food, medicine, biology and other fields because it can dry materials at lower temperatures and retain the active ingredients of materials. However, if the equipment is not cleaned and sterilized properly after use, residual materials can breed microorganisms and cause cross contamination, which not only affects the accuracy of subsequent experimental results but may also damage equipment components. Therefore, mastering scientific and standardized cleaning and sterilization methods is a key link in the maintenance of laboratory low-temperature spray dryer.
Before carrying out cleaning work, it is necessary to make sufficient preparations. Firstly, ensure that the equipment is in a power-off and shutdown state, unplug the power plug, and avoid the risk of electric shock during the cleaning process. Secondly, prepare specialized cleaning tools such as soft brushes, specialized cleaning cloths, plastic scrapers (to avoid scratching the inner walls of the equipment), and suitable cleaning agents. Neutral cleaning agents (such as medical neutral enzyme cleaning agents) are usually selected, and strong acids, alkalis, or corrosive cleaning agents are strictly prohibited to prevent damage to the stainless steel inner walls and sealing components of the equipment. At the same time, operators need to wear protective equipment such as disposable gloves and masks to avoid contact between cleaning agents and the skin or inhalation of dust generated during the cleaning process.
The cleaning process should follow the principle of "from inside to outside, dismantle first and wash later". The first step is to disassemble the detachable components, including the feed pipe, nozzle, cyclone separator, collection bottle, etc. Put these parts into the prepared neutral detergent solution (the concentration is usually 1% -2%) and soak them for 15-20 minutes. During this period, gently brush the inner walls and gaps of the parts with a soft bristle brush to remove the residual material residues. Pay special attention to the small aperture of the nozzle, and use a special drift pin to dredge, so as to prevent blocking from affecting the subsequent spray effect. Step 2, clean the interior of the equipment host. Dip a cleaning cloth in a small amount of neutral detergent solution and wipe the inner walls, hot air inlet and outlet of the drying chamber. For stubborn stains, gently scrape them off with a plastic scraper before wiping to avoid damaging the inner wall coating with excessive force. Step three, clean the exterior of the device, wipe the surface of the device with a clean damp cloth to remove dust and stains, and finally dry it with a dry cloth to prevent moisture residue from causing the device to rust. After cleaning all components, rinse them 2-3 times with deionized water or purified water to ensure no residue of the cleaning agent. Then place the components in a sterile drying oven and dry them at 60-80 ℃ for later use.
The sterilization process needs to select appropriate methods based on experimental requirements and material characteristics. The commonly used sterilization methods include high-temperature sterilization and ultraviolet sterilization. High temperature sterilization is suitable for high-temperature resistant components. Place the cleaned and dried components in a drying oven, set the temperature to 121 ℃ and pressure to 0.1MPa, and maintain it for 20-30 minutes to effectively kill bacteria, fungi, and other microorganisms; For the interior of the device host, hot air circulation sterilization can be used, with a set temperature of 80-100 ℃ for 1-2 hours to ensure sterilization of the internal space. UV sterilization is suitable for components and internal surfaces of equipment that are not resistant to high temperatures. Install UV lamps inside the equipment, close the equipment door, turn on the UV lamps, and irradiate for 30-60 minutes to use the sterilization effect of UV rays to kill microorganisms. It should be noted that ultraviolet radiation can harm human skin and eyes. During the sterilization process, personnel should stay away from the equipment. After sterilization, ventilation should be maintained for at least 30 minutes before opening the equipment door.
In addition, the following precautions should be taken during the cleaning and sterilization process: firstly, the cleaning frequency, which should be carried out after each use of the equipment, and comprehensive sterilization should be carried out at least once a week; The second is component installation. The sterilized components need to be installed in a sterile environment to avoid secondary contamination; The third is equipment inspection. After cleaning and sterilization, it is necessary to check whether the equipment components are installed in place and whether the sealing is good to ensure the normal operation of the equipment. Only by strictly following the scientific cleaning and sterilization methods can the stable operation of the low-temperature spray dryer in the laboratory be guaranteed and the accuracy and reliability of the experimental results be improved.