There was no observed influence on residual moisture and it was calculated that more than 50% of the cooling capacity could be saved during primary drying (PD). During secondary drying (SD), the energy savings were lower because of the lower set pressure. Yet, because of the COP, the electrical power savings in the fluid compressor were significantly higher.
Further trials were then done with 5% sucrose. Again, taking an average of five runs, the ECO Mode process time was slightly higher; but, as per the mannitol tests, more than 45% of the cooling capacity could be saved during PD. Likewise, significant electrical energy savings could be made with no influence on residual moisture .
In Summary
This new algorithm changes the set point of both the fluid condenser temperature and the position of the mushroom valve during drying. What this means is that there’s no longer an actual fixed temperature for the condenser; it’s optimally matched to the ongoing process and no colder than necessary.”
In addition, the mushroom valve opening position can optionally be used as an extra control mechanism … as well as the nitrogen inflow rate. This allows the freeze dryer to reach the same chamber pressure, but with warmer condenser coils. As such, less nitrogen is needed to control the pressure. The system can also be augmented with a virtual sublimation sensor if required.
Retrofit-compatible with any unit with a fluid condenser, and with the option to run existing processes in classic mode, ECO Mode will be a selectable recipe parameter that will transform the future of planet-friendly freeze drying.