Solar Tunnel Dryers

Koldware Industries (Pvt) Ltd. offers the most amazing solar drying tunnels which can be installed at your premises and which can help you dry crops.
Solar tunnel dryers utilize the energy of the sun and wind to dry agricultural products, preparing them for proper storage, processing and export. The crop is spread in an even layer on tables or drying racks inside the tunnel. The air below the semi-transparent collector is heated by the sun and spreads throughout the tunnel. The increased temperature decreases the relative humidity of the air, thereby allowing the air to dry the crop more efficiently.
Solar tunnel dryers change the process of drying crops compared to the traditional open-air method. High economic benefits of the dryers result from improved efficiency and a decrease in required labor. Solar drying is a continuous process where moisture content, air and product temperature change simultaneously along with the two basic inputs to the systems: the solar insolation and inlet air at ambient temperature. The drying rate is affected by ambient climatic.

Conditions This includes temperatures, relative humidity, sunshine hours, solar insolations, wind velocity, frequency and duration of rain showers during the drying period etc. To have a valuable quality product and to minimize the wastage, artificial drying of the product should be employed. The earlier dryers used conventional fuels like electricity, coal and fossil fuel .Drying of agricultural product is an energy intensive operation. High cost of fossil fuel and gradual depletion of its reserve has incited the use of solar energy as an alternative energy source for dryers.

The major advantages of drying fruits and vegetables are given below

  • Drying hardly affects the main calorie-providing constituents.
  • Dried fruits and vegetables have a longer shelf-life under proper storage conditions.
  • Transportation, handling and storage costs are substantially lowered.
  • They provide a consistent product, an important modern marketing requirement.
  • They utilize the most economical and disposable form of packaging
    Produce Moisture Content (% W.B) Max.Permissible Temperature
    Initial Final
    Green Peas 80 5 5
    Green Beans 70 5 75
    Cauliflower 80 6 5
    Cabbage 80 4 55
    Onions 80 4 55
    Chilies 80 5 65
    Potatoes 75 13 75
    Tomatoes 96 10 60
    Brinjal 95 6 60
    Apple 80 24 70
    Apricots 85 18 65
    Peaches 85 18 65
    Grapes 80 15-20 70