What is dome dryer?

Dome dryer is equipment having a structure like a dome and used to dehydrate things like vegetables and fruits. It is the second prototype on which I am working basically designed for 25 kg pomegranate gem-like seeds inside the fruit.

how dome dryer works?

It has six plates on which you can put things which you want to dehydrate. The outside air fetched inside from the holes and it exhaust air using exhaust fan mounted on the middle pipe. Drying is a  mass transfer process consisting of the removal of water by evaporation from a solid, semi-solid or liquid. This process is often used as a final production step before selling or packaging products. To be considered “dried”, the final product must be solid, in the form of pieces (like onion), particles (e.g., cereal grains or corn flakes) or powder (e.g., moringa).

Advantages Of Dome Dryer

  1. Efficient Heating Device
  2. Portable- It is compact in size and extremely portable. It is also light in weight which is one of the greatest advantages of using this device.
  3. Ample Protection- The food items can be protected well with appropriate screening device.
  4. Direct and indirect heating- This device utilizes both direct and indirect solar energy for quick drying purposes. It also offers optimum performance and so the food items last for a longer period of time without losing their nutritional values.


If temperature and humidity will not get maintained well food item may get fermented.

Trial 1:

The first trial on dome dryer started on 16 NOV’18. The onion batch of 25 kg loaded at 4:45 pm. The loss on drying(LOD) of dome dryer was 91.35 and LOD of an oven was 82.16.

Loss on drying is a widely used test method to determine the moisture content of a sample, although occasionally it may refer to the loss of any volatile matter from the sample. Loss in drying does not usually refer to molecularly bound water or water of crystallisation.

fig1. dried onion after 2 days


Here we have taken only one LOD, because of that we didn’t get the proper result and drying, within specified days.

Next Plan:

Do data analysis and calculations.