Grain Systems PNEG-1851 - Manual (Page 49)

Chapter 5: The Drying Modes
Figure 5-8 Dual-setpoint time control scheme in the dry and cool operation
NOTE: In full-heat operation, the cooling phase is simply bypassed. As a result, the unloading phase
starts immediately following the drying phase, allowing uncooled, hot grain to be discharged from
the dryer.
Staged Batch Based on Grain Temperature
Temperature-based control schemes in staged batch use grain temperature sensors as their reference
parameter. Use these schemes when you would like the grain temperature to dictate the moisture content
and unload grain at a specific temperature.
How It Works
During the drying phase, all fans and heaters are activated so that the plenums can reach their respective
setpoints. The drying phase continues until the grain temperature reaches a defined temperature setpoint.
Once this setpoint is reached, the heaters stop, the drying phase ends, and then the cooling and unloading
phases follow one after the other.
To better control the grain’s final temperature, it is also possible to alter the plenum setpoint when the grain
temperature reaches a predefined temperature. By doing so, the wet grain is exposed to two different
drying temperatures within the same drying phase. The drying phase ends when the grain temperature
reaches its final temperature setpoint (see
The Dual-Setpoint Temperature Control Scheme, page 50 for
details).
The Temperature Control Scheme
In the temperature control scheme, you enter the following parameters:
• The grain temperature setpoint
• The temperature setpoint of each plenum
As shown in the following figure, the drying phase starts when the load auger fill switch is activated and
stops when the grain temperature reaches its setpoint. A cooling phase immediately follows, and the dry
and cool grain is then discharged from the dryer during the unloading phase.
PNEG-1851 Vision N2 49