Drying temperature: How does it affect processing time?

Tests conducted by UC Davis (California) clearly demonstrate this behavior. When the air temperature is increased from approximately 32 °C to 43 °C, the time required to complete drying decreased from 25.25 hours to 14.5 hours.
This represents a reduction of approximately 43% in processing timesimply by modifying the operating temperature.

Let's see this reflected in a graph:

The efficiency of a dryer depends not only on how much heat it delivers, but also on how long it needs to deliver it to complete the process.

So, is it always best to use the highest possible temperature?

Not necessarily.

The goal of drying is not only to finish the process quickly. It is also to achieve the desired final moisture content without unnecessarily subjecting the product to more demanding conditions.

Therefore, rather than thinking about a single temperature, it is interesting to think about how the temperature should evolve during the process.

From traditional drying to smart drying.

In many conventional systems, a temperature is set and kept practically constant until the end of the cycle. However, the condition of the nut is not the same at the beginning as it is after several hours of drying.

This opens the door to a different strategy: measure what is happening inside the dryer and automatically adapt its operation.

An intelligent drying system can use sensors distributed throughout the product mass to monitor its evolution and modulate the heat input based on the measured conditions. Instead of simply asking ourselves:

"At what temperature should we dry?"

We can begin to ask ourselves:

“What temperature does the product need at each stage of the process?”

This change in approach allows us to move from a dryer that simply maintains a temperature to a system that actively manages the drying process.