The automatic liquid refilling system is a core supporting module of liquid nitrogen generators, which realizes unattended automatic liquid level monitoring, quantitative refilling, and liquid storage protection of liquid nitrogen storage tanks, effectively solving the problems of manual refilling error, liquid nitrogen waste, and low automation operation. The system is widely used in laboratory cryogenic experiments, medical freezing, industrial cryogenic processing, and food quick-freezing scenarios, and its configuration parameters directly determine the stability of liquid nitrogen output and the safety of storage tank operation. A qualified automatic liquid refilling system must meet the requirements of real-time monitoring, precise control, safety protection, and intelligent linkage.
In terms of hardware configuration, the automatic liquid refilling system must be equipped with high-precision liquid level sensors, electromagnetic control valves, pressure transmitters, and intelligent PLC control modules. The liquid level sensor adopts cryogenic resistant stainless steel probe, which can adapt to the low-temperature environment of -196℃ of liquid nitrogen, with a monitoring accuracy of ±2mm, realizing real-time collection of liquid level data in the storage tank. The system sets high and low liquid level threshold values: when the liquid level is lower than the low threshold, the system automatically opens the refilling valve to start liquid nitrogen supplementation; when the liquid level reaches the high threshold, it automatically closes the valve to stop refilling, realizing fully automatic quantitative liquid supplementation without manual intervention. The matched pressure transmitter monitors the tank pressure in real time to avoid liquid nitrogen gasification caused by excessive pressure.
In terms of safety and linkage configuration, the automatic liquid refilling system needs to be equipped with multiple safety protection devices and remote monitoring functions. It is necessary to configure anti-overflow protection, overpressure relief protection, and low-temperature anti-freezing protection modules. Once the liquid level overflows or the tank pressure is abnormal, the system will trigger an alarm and cut off the refilling pipeline in time. At the same time, the system supports data linkage with the liquid nitrogen host, which can adjust the liquid nitrogen liquefaction and output speed according to the liquid level change of the storage tank to realize dynamic matching of production and storage. In addition, the system is equipped with a digital display screen and remote transmission function, which can view liquid level data, refilling records, and equipment operation status in real time, and support automatic data recording and fault alarm reminder, greatly improving the intelligent operation level of liquid nitrogen generation equipment.
