Objective
The objective of the project is to demonstrate how two types of modular solar driers, with collecting surfaces built into their roof, can be used to dry mechanical and aromatic plants. The first type of drier will be used for drying thin layers of plants i.e. plants whose shape and form must be maintained; the second for thick layers.
Apart from the added value to the products, the total energy saved with the 10 dryers will be 7 TOE/yr; payback between 3 and 6 years.
The project consists of the design, construction and operation of 10 solar driers adapted for producers of mechanical and aromatic plants requiring either thin or thick drying layers.
Each drier must :- maintain the correct temperature humidity and ventilation rate
- give enough natural light in the working areas
- have sufficient space in which other post-harvest operations can be carried out.
THIN LAYER DRIER
The drying bed is composed of 7-12 m2 shelves placed in a rack. The plants to be dried will be spread out making a layer from 1-20 cm thick. Thus drier is therefore adapted to fragile plants. Because the shelves are moved by hand, the number of plants to be treated is limited.
THICK LAYER DRIER
In this case each shelf may be from 5-20 m2 and the thickness of the layer of plants varies between 20 cm and 1 m. This drier is therefore of interest to cultivators with 50000 m2 or more.
OPERATION
Similar in both cases. A solar air collector is integrated into the roof. Glazing mayor may not be used; air circulates between the cover and insulation with the aid of a fan. Hot air collected thus, is ducted to the base of the plants to be dried and is then evacuated after passing through the plant layers. The characteristics of a drier to be built in St Girons en Ariege are :
Collector surface 10 m2
Water evaporated 23 Kg/day in July maximum weight of fresh plants 30 Kg/day or 1 T/yr humidity reduced from 80-15%.
The cost of the first drier is ca 41000 FF and the cost nd the cost of the second is ca 34000 FF.
Topic(s)
Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
34190 GANGES
France