Technical Exchange on Maintenance and Overhaul of Dongfulong Pharmaceutical Lyophilizers

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This post was last edited by YORK Industrial Freezing on 2017-4-26 at 20:21. Feel free to ask me any technical questions. With the continuous advancement of lyophilization technology and lyophilizers, lyophilization is being used more and more widely in the development of sterile preparations. Throughout the process of producing lyophilized sterile formulations, the lyophilization step is the most critical one. Lyophilization technology is widely used in the pharmaceutical industry for antibiotics, antitoxins, interferons, bacteria, viruses, vaccines, blood products, diagnostic agents, enzyme preparations, vitamins, hormones, culture media, traditional Chinese medicine preparations, and more ； In aseptic pharmaceutical production, the main components include active pharmaceutical ingredients, as well as lyophilized injections and tablets. A flowchart of the lyophilization process is attached below: https://imgsa.baidu.com/forum/w%3D580/sign=e122cee8a551f3dec3b2b96ca4eef0ec/6ca788d98d1001e94535122db20e7bec54e79777.jpg Industrial_Process.JPG (62.75 KB, downloads: 0) Download attachment; save to album. Uploaded half an hour ago. The two most important systems in a lyophilizer are the refrigeration system and the vacuum system. The refrigeration system is the heart of the freeze-drying system. It mainly consists of the following components: compressor, refrigerant, oil separator, water condenser, dry filter, intercooler, sight glass, solenoid valve, manual valve (roof valve), expansion valve, evaporator (plate exchanger, rear box condensing coil), vapor-liquid separator, return air filter, pressure gauge, pressure control relay, CPCE (energy regulator), safety valve, and refrigeration pipes. The system diagram is attached below: https://imgsa.baidu.com/forum/w%3D580/sign=80ce9c43f9deb48ffb69a1d6c01f3aef/b3b2791001e939015c0b8b1c71ec54e736d19677.jpg 1. Daily maintenance of the refrigeration system (1) A routine inspection should be carried out before each startup ； Are all stop valves (compressor suction and exhaust valves, liquid supply valves, manual valves, etc.) in the open position? ； Are the readings of all pressure gauges normal (0.6–0.7 Mpa)? Is the level of the compressor oil normal (1/4–3/4)? Are the pressure and temperature of the cooling water normal (above 0.1 Mpa)? (2) After power is supplied, pay attention to whether the compressor automatically collects liquid ； Whether the oil pressure difference has been reset, etc ； Check the heating performance of the crankcase heater; the temperature of the crankcase should be 20°C higher than the ambient temperature. (3) After turning it on, pay attention to whether the sound of the compressor during operation is normal ； Are there any abnormal vibrations in the refrigeration piping? ； Whether the vibration of the compressor itself is minimal depends on whether the sight-glass flow is normal ； Frosting on the expansion valve ； Compressor defrosting condition ； (4) The compressor refrigeration oil should be replaced every six months or one year, depending on the circumstances. (5) The water condenser needs to be cleaned regularly, usually once a year. It can be disassembled for cleaning, or cleaned cyclically using water-based cleaning agents. For air-cooled units, clean the outer surface of the condenser promptly. (6) Be careful not to start the compressor frequently. (The startup interval should be greater than 3 minutes.) Below is a link to cases of overhauls of Kobe Steel two-stage screw compressors, Maekawa two-stage screw compressors, and Bizerba piston pumps used in Dongfulong freeze-dryers: https://imgsa.baidu.com/forum/w%3D580/sign=d165c0ccbe8f8c54e3d3c5270a292dee/427bf5e93901213fc63a48fe5ee736d12f2e9577.jpg The vacuum system is an important component of freeze-dryers; it mainly consists of a drying chamber, a condenser, a vacuum pump, a Roots pump, small butterfly valves, chamber isolation valves (large butterfly valves, mushroom valves), vacuum testing equipment (vacuum gauges, vacuum tubes (pressure sensors)), venting devices, auxiliary devices, and vacuum pipes. https://imgsa.baidu.com/forum/w%3D580/sign=4d60655c9858d109c4e3a9bae158ccd0/68843a1b9d16fdfa3f65c0ccbe8f8c5494ee7b77.jpg Daily maintenance of vacuum systems: (1) Before starting the vacuum pump, check its oil level (it should generally be at 1/2 of the oil sight glass). (2) Before starting the vacuum pump and the small butterfly valve, ensure that the front box door is closed and that all valves are in the closed position. Before starting to evacuate the chamber with the vacuum pump, it is essential to ensure that the rear chamber is dry. If there is moisture present, the temperature of the condenser must be kept below -45°C, and this temperature must remain below -45°C throughout the entire freeze-drying process, in order to prevent moisture from being drawn into the pump and affecting its operation. (3) If the vacuum pump and rotary vane pump used require water cooling, it is essential to ensure that the cooling water is available before the vacuum pump is started; during operation, one can touch the surface of the pump to check its temperature. The Roots pump should not be started too early (controlled by a contact pressure gauge). (4) The vacuum pump oil needs to be replaced regularly, usually once a year. When the vacuum pump is in operation, pay attention to the changes in the color of the oil shown on the level gauge. If a white turbidity appears in the upper part of the oil during operation, consisting of small white droplets, it indicates that moisture or organic solvents have entered the vacuum pump. In such cases, open the air vent valve for a certain period of time (depending on the actual situation; generally around 1 hour) ； If the pump oil remains milky white, black, or of some other color for an extended period of time, it indicates that the oil has deteriorated and emulsified, and it is necessary to replace the vacuum pump oil. (5) After starting the vacuum pump, do not open the small butterfly valve yet; allow the vacuum pump to evacuate the vacuum tube for some time first, and check whether any noise is generated during its operation Can an ultimate vacuum be achieved within a normal time frame? If there are any changes, please first check whether the vacuum pump oil has deteriorated, whether the solenoid valve on the pump head is functioning properly, and whether there are any loose connections on the pump head. Below are several common vacuum pumps used in Dongfulong lyophilizers: AirTAC vacuum pumps, Edwards vacuum pumps, Edwards Roots pumps, and Shanghai Kaini Roots pumps. https://imgsa.baidu.com/forum/w%3D580/sign=c77aa14adb09b3deebbfe460fcbf6cd3/01706916fdfaaf5162ea879d865494eef01f7a77.jpg https://imgsa.baidu.com/forum/w%3D580/sign=006ce21bb9de9c82a665f9875c8180d2/527d09faaf51f3de26bbbf469eeef01f3a297977.jpg https://imgsa.baidu.com/forum/w%3D580/sign=423d80cc9682d158bb8259b9b00a19d5/32915b51f3deb48f1f60a7fcfa1f3a292df57877.jpg https://imgsa.baidu.com/forum/w%3D580/sign=27eaaf90db58ccbf1bbcb53229d8bcd4/603a07deb48f8c5400dac30d30292df5e0fe7f77.jpg