Seed Drying Methods
Wagon Drying:
Wagon drying is a special type of batch drying with heated air which is finding extensive use. In this system, the seed is loaded directly from the combine on to the wagon, which is specially constructed so that it can be used for drying. The wagon is then drawn to the drier, to which it is connected with a canvas distributing duct. Three or four wagons can be dried at once. The seed is dried by hot air forced up through perforations in the wagon floor. The wagon is then disconnected from the canvas duct and drawn to one side where seed is cooled with a small fan of 1 ½ horse power, as required. After the seed is cooled, the wagon is towed to the storage bins.
Wagon drying has the following advantages:
1. Drying is essentially continuous;
2. High versatility
3. Low initial cost;
4. Saves on seed handing;
5. Easy cleaning and
6. Can be used for other purposes.
Bag Drying:
The drying of seeds could be done in bags also. This is particularly suited when many varieties are handles simultaneously, or when the seed lots are small in size and seed is received from the field in jute bags. Excellent air flow with minimum static pressure is possible because the drying bed is only one sack deep. Typical design criteria provide 25 to 40 cubic meters of air per minute, per cubic metre of seed at a static pressure of 3 cm, or even less. The construction is simple and inexpensive.
Box Drying:
The box drier is a modified bag drier. It is well- adapted for use in basic seed drying operations. With box driers, the identity of small seed lots can be maintained, despite bulk handling. The boxes, generally constructed of locally available materials, are fitted with perforated metal or woven wire bottoms. After the seed is dried, the filled boxes are removed from the drier and placed in a temporary storage area, thus making room on the drier for additionally boxes. This type of drier requires that the enough specially constructed boxes be maintained.