Cell Freeze-Drying System Using Warm Nitrogen Sublimation
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Solution Overview
Problem
Current cell freeze-drying methods cause microstructural damage and have low recovery rates due to temperature differences and equipment pollution, making them inefficient and costly.
Innovation Solution
A cell freeze-drying system using a temperature-elevated nitrogen supplier, a freeze-drying operation box, and a gas discharger, where warmed gaseous nitrogen is continuously supplied to the precooled operation box to sublimate solid state water in cell samples at a temperature suitable for liquid nitrogen, minimizing temperature differences and using nitrogen as a low-cost, inert sublimation medium.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If vacuum freeze-drying method is used to control gaseous water pressure and provide sublimation energy, then cell dehydration can be achieved, but microstructural damage occurs and recovery rate decreases due to internal stress and temperature differences
Solution Approach 1:
The invention changes the working pressure parameter from vacuum to atmospheric pressure, and changes the heating method from external vacuum heating to internal warm nitrogen gas heating. This allows sublimation to occur at atmospheric pressure with minimized temperature difference between the cell sample and surrounding environment, reducing thermal stress and microstructural damage while improving cell recovery rate
Solution Approach 2:
The invention introduces warm nitrogen gas as an intermediary medium that serves dual functions: providing sublimation energy through controlled heating and maintaining atmospheric pressure environment. The nitrogen gas directly contacts the cell sample, enabling gentle and uniform heating that minimizes thermal shock and internal stress, thereby preserving cell microstructure
2Quantity of substance
If vacuum pump operates continuously for more than 24 hours to maintain negative pressure state, then gaseous water partial pressure can be controlled, but lubricating oil is consumed and vapourised, causing severe vibration and noise pollution
Solution Approach 1:
The invention extracts and eliminates the vacuum pump from the system by changing the working principle from vacuum freeze-drying to atmospheric pressure freeze-drying with warm nitrogen gas. This removes the source of vibration, noise, and lubricating oil pollution while achieving the same sublimation effect through a different physical approach
Solution Approach 2:
The invention uses nitrogen gas to create an inert atmospheric environment that enables freeze-drying at atmospheric pressure. The nitrogen atmosphere provides the necessary conditions for sublimation without requiring vacuum, thereby eliminating vacuum pump-related pollution and mechanical disturbances
3Temperature
If initial operating temperature is set not lower than −90° C. to match industrial equipment capabilities, then equipment operation is feasible, but huge temperature difference with liquid nitrogen causes cell damage
Solution Approach 1:
The invention applies preliminary action by pre-cooling the cell sample to liquid nitrogen temperature (−196° C.) before placing it in the freeze-drying chamber. The chamber is then filled with warm nitrogen gas, creating a controlled temperature gradient that gradually warms the sample while maintaining atmospheric pressure, thus minimizing thermal shock and cell damage
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces cell damage, achieves safe, efficient, and low-cost freeze-drying by maintaining sublimation under normal pressure with minimal environmental pollution and energy consumption, ensuring effective dehydration of cell samples.
Implementation Method 1
the freeze-drying operation box is warmed up in a preset mode while continuously being supplied with the warmed gaseous nitrogen after a cell sample is placed in the freeze-drying operation box in order to freeze-dry the cell sample, such that solid state water in the cell sample is sublimated into gaseous water
Data Source
AI summary
A cell freeze-drying system, comprising: a temperature-elevated nitrogen supplier, a freeze-drying operation box, and a gas discharger, which are connected in that order using a first connection pipe. The temperature-elevated nitrogen supplier supplies warmed nitrogen to the freeze-drying operation box. A cell sample frozen by liquid nitrogen is placed in the freeze-drying operation box, and then the freeze-drying operation box, which is preset to a temperature suitable for placing the cell sample frozen by liquid nitrogen, is warmed up in a preset mode while continuously being supplied with the warmed nitrogen to sublimate solid state water in the cell sample into gaseous water. The gas discharger is used to discharge the gaseous nitrogen and the gaseous water. Further disclosed is a cell freeze-drying method. The invention can effectively address an issue of cell damage and contamination during freeze-drying, and realizes safety, efficiency, and low costs for cell freeze-drying.