This blog is about second field trial of dome dryer v2.0. In this trial, we decided to load the trial at its maximum capacity. For this, we chose diced onion as a substrate. Below are details of trial.


  • I cleaned the dome dryer.
  • I diced 25 kg onion for the trial as per given full capacity of the dryer.
  • Measured weight of waste onion parts and useful parts. Noted down data.
  • I have loaded 12 kg diced onion batch loaded at 1pm on 20th November 2018.
  • Then I took 12 samples of 10 gm onion for finding a loss on drying(LOD) after 24 hours from batch loaded.


I observed the onion slices were not evenly divided, because of that it took more time to dehydrate. Dixit sir and I did the calculation using each plate surface area and found, I have to load only 12 kg onion slices instead of 25 kg for proper drying.

This time I have decided to take 12 samples, 2 samples from each plate one was inside and another was outside to increase the rate of dehydration and decrease time of dehydration.

fig1. onion after 24 hours from batch loaded
Fig. The all onions infected by fungus and spoiled.


Because of sudden climate change humidity in outside air increased and onions were infected by fungus and they were spoiled. All plates and onion have become black as shown in figure2.

Next Plan:

This onion batch infected with fungus and onions were spoiled, I will find out reasons and solve it.