The capture performance of a freeze-drying machine is determined by the surface area of the cold trap coil (usually in the form of a coil) when designing the entire machine.

When frost forms on the surface of the cold trap, the surface temperature will rise. To compensate for the increase in frost surface temperature and reduce the efficiency of capturing water vapor, many freeze-drying machines initially use expanding the condenser surface area or reducing the temperature of the cold trap. As a result, the refrigeration system of freeze-drying machines is huge, resulting in uneconomical energy consumption during operation.

The current good solution is to adopt a dual cold trap structure. When one cold trap is capturing water vapor, the other cold trap defrosts and waits for it to be ready, which can timely remove the frost layer and prevent excessive frost formation.

If the condensation control of the double cold trap equipment is not well switched, it is easy to cause the vacuum pressure inside the freeze-drying chamber to rise during switching, increasing heat conduction and causing temperature fluctuations in the product. As shown in the figure below, a fluctuation in the temperature of regular products is caused by the switching of cold traps.

At present, Shuangjia Instrument has successfully solved the problem of switching through redesigning and controlling the process.

The double cold trap freeze-drying machine is used on medium to large production equipment, which can reduce energy consumption for scenarios that do not require continuous work. For scenarios that require continuous production, it can also avoid the time delay of defrosting after each operation, thereby improving efficiency.

Desktop freeze-drying machine - click to go