Tray dryer for automatic seed drying

Drying of a small amount of seed does not always get the attention it deserves. The tray dryer of Agratechniek dries the seed in every tray automatically to the desired moisture content. This can vary per tray. The drying process starts automatically when the tray is placed and the mesh lid (b) is closed.

The fan rotation (f) will increase to create the desired amount of additional air. A T° and RH sensor (c) above each tray measures the air from the seed. When the desired moisture content is reached, the slide (d) closes gradually and the fan rotation decreases. When the slide is closed, the seed is dry.

Cross section of the static tray dryer (in this example containing 6 trays; more or less trays is possible):

A: Place a tray with an opened mesh lid
B: Tray placed and mesh lid closed
C: Measurement of T° and RH of the air from the seed
D: Slide for automatic opening and closing
E: Electrical heating for additional heating up

F: Central fan for air measurement

G: Heating radiator for desired basic T°

H: Valve register for inside air (recirculation)

I: Valve register for aspiration of outside air

J: Valve register for supply of dried air

The electric heating (g) ensures a separate temperature can be provided per tray or per drying phase. After the desired time or desired moisture content, the T° can be readjusted in a next phase.

Cross section without tray; the lidwith sensor (c) has been opened toplace a tray.

Cross section of tray with mesh lidstill open; drying process has notstarted yet

Cross section of tray during dryingprocess; mesh lid closed and slide(d) opened.

The fan automatically provides more air when an additional tray is placed. When the seed in a tray begins to dry,the slide (d) closes gradually. When this occurs, the air quantity will decrease automatically, durinhg which thedesired moisture content is maintained.

The T°+RH measurement sensor (c)has been mounted onto the covergrid using a funnel, to measure theair condition from the seed.

A high pressure fan (f) with builtinair measurement can giveadditional air quantity whenplacing a tray.

An electric heating (g) ensures theair T° can be heated up additionallyper phase.

The slide is closed when no tray hasbeen placed and the lid is opened(K). The slide is opened to dry a trayof seed with a closed lid (L).

A heating radiator (g) ensures theair is heated up to a desired basicT°. Afterwards the T° can beheated up additionally per phase.

Valve section for aspiration of insideair (h), outside air (i) and dried air (j)from the central air dryer.

The dried air from the central air dryer mixes with the inside or outside air. Therefore, it continuously creates the desired moisture content of the air. This can vary per phase. The drying process takes place completely controlled and always reaches the desired moisture content.

The drying process usually stops when the air from the seed has reached the desired moisture content. Therefore the air from the seed will be measured (c). Another possibility is to end the drying process when a desired amount of moisture around the seed has been evaporated. The drying process will stop when the original weight of the seed has been reached.

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