Safety and Protection Devices安全及保護裝置
凍干機裝有以下安全及保護裝置，以確保設備在程序中的可靠性：
如果斷電：
? 箱體和冷阱之間的主閥位置沒有變化
? 所有其它的閥門都關閉以保持設備內部的完整性，真空泵抽氣管上裝的安全閥關閉以防止真空泄漏
? PLC 的電池可以保持儲存的信息，PLC 程序也儲存在EEPROM 中
? 來電后，程序將從斷電時的程序點重新開始其它安全裝置：
? 每個壓縮機上裝有一個壓力開關，可以在排出口壓力過高時，自動斷開壓縮機
? 在制冷管路中由于溫度升高（主要是設備停機時）會造成低壓側的壓力升高，每臺壓縮機上都有一個低壓開關來防止壓力升高，壓縮機自動起動并向高壓側回收制冷劑。
? 如果在升華階段，箱體真空上升到警戒點以上，擱板加熱將會自動切斷，如果真空繼續(xù)上升，擱板將開始冷卻
? 當過溫時，2 個安全溫度調節(jié)器會切斷硅油加熱器
? 如果壓差下降，備份泵啟動，一個壓差開關監(jiān)視器會監(jiān)測循環(huán)泵（僅適用于雙泵系統(tǒng)）
? 當缺油或者油泵不工作時，每臺壓縮機上的油壓差開關會切斷壓縮機
? 所有的電機上都裝有D立的過載切斷開關
? 軟件中的內部自鎖程序可防止誤操作，如當箱體和冷阱在真空狀態(tài)下打開排水閥和化霜入口閥
The freeze dryer is equipped with the following safety and protection devices to ensure total process reliability:
In the event of power failure:
?The position of the main valve between the chamber and the ice condenser remains unchanged
?All other valves are closed to maintain the plant integrity. The valves in the inlet to the vacuum group are automatically closed to prevent leakage through the pumps.
?The PLC has battery backup, to ensure information is retained. The PLC program is also stored in non-volatile EEPROM memory.
?When power is re-established, the cycle is resumed from the same point where the power failure occurred
Other safety features:
?A high pressure switch on each refrigeration compressor stops the compressor in the event of high discharge pressures.
?On each compressor, a low pressure switch prevents a pressure increase in the low-pressure side of the refrigeration circuit due to any temperature increase (typically when the plant stops). The compressor automatically starts and transfers the refrigerant to its high-pressure side.
?If the chamber vacuum rises above a programmed alarm point during the sublimation sequence, shelf heating is automatically switched off. If the vacuum continues to rise thereafter, shelf cooling is initiated.
?Two safety thermostats switch off the silicone oil heater should an over-temperature condition arise.
?A differential pressure switch monitors the performance of the duty circulation pump. If the differential pressure falls the standby pump is started (only applicable for machines with two circulation pumps).
?Differential oil pressure switches on each refrigeration compressor switch off the compressor in case of lack of oil or failure of the oil pump.
?All motors are fitted with individual over current breakers.
?Software interlocks prevent miss-operation of the equipment e.g. opening drain or defrost inlet valves when the chamber and condenser are under vacuum etc.
Alarm List報警列表
ALARM LIST報警列表 | |
Process Alarms 工藝報警 | Component Alarms部件報警 |
Poor Vacuum – Two alarms 真空不足 – 兩個報警 | High Refrigerant Pressure 制冷劑壓力高 |
High Shelf Temperature 擱板溫度高 | Low Compressor Oil Pressure 壓縮機油壓低 |
Low Shelf Temperature 擱板溫度低 | Low Compressed Air Pressure 壓縮空氣壓力低 |
Low vacuum 低真空 | High Silicone Oil Temperature 硅油溫度高 |
Low Silicone Oil Pressure 硅油壓力低 | |
Low Cooling Water Pressure 冷卻水壓力低 | |
Other depending on mc. Specification 基于指標的其它報警 | |
Note 注: The operator is notified audibly of alarms by a horn and visually by a lamp, computer screen displays. 操作者將通過聲光報警及屏幕顯示得到報警通知。 | |
