Troubleshooting a flat-bed dryer

• Too high drying temperature
• Immediate milling after drying

• Adjust drying temperature to below 45^oC.
• Wait 1day before milling.

Loss of germination due to drying

• Too high drying temperature

• Adjust drying temperature to below 42^oC.

Non-uniformity of final MC (more than 2.5 %)

• Packed bed due to excessive stepping over 
• Non-uniform material (mixed wet and dry, clean and dirty grain)
• Non-uniform grain depth Perforated floor is partially stuck (holes are filled with dust)

• Avoid stepping on the grain mass (use a woodboard if necessary).
• Pre-clean the grain to remove gross impurities.
• Adjust depth at local spot after 2/3 of the drying time is spent.
• Clean the floor after three batches.

Too much ash in the
plenum (under the bin)

• Ash precipitation chamber full of ash
• Exit spout of the furnace too close to the fan inlet

• Clean ash from the precipitation chamber
• Move the spout farther from the fan inlet

Smoky combustion

• Excessive husk feeding rate
• Lack of secondary air for combustion
• Wet rice husk

• Reduce feeding rate.
• Check the air inlet supply.
• Use dry rice husk.

Prolonged drying time

• Not enough airflow
• Leakage of drying air
• Very wet intake paddy
• Close shed, not suited for ventilation

• Increase engine speed (diesel engine) or change pulley size (electric motor). 
• Close leak points.
• Reduce grain layer depth.
• Clear obstruction around the shed.