Onion and potato box storage, forced ventilation through suction wall

Storage of onions and potatoes in boxes with forced ventilation, using a suction wall.

Storing onions or potatoes in boxes has the advantage that the produce is not crushed by being stacked up to 4 metres high. In addition, produce in boxes is compartmentalised, and so in the event of contamination or disease, the problem will not spread throughout the facility, but will be confined to that one box.

Box storage makes it necessary to invest in boxes, but the handling and logistics are very simple. The only specialised equipment you need is a forklift truck. Have a look how bulk storage and box storage facilities are filled and emptied here..

Box storage, with forced ventilation through the produce, is ideal for delicate products, such as short-day onions.

A suction ventilation wall for an onion or potato storage facility. The man is standing in front of the vertical ventilation hatches in the wall. At each side of these vertical hatches, boxes are stacked, forming an aisle. That aisle is covered by a canvas to form a suction chamber between the two rows of boxes.

The green canvas covers a kind of aisle made out of two rows of boxes. At the end of the aisle there are vertical hatches that give access to the space behind the suction wall. These hatches are opened according the number of boxes stacked.

View from above. One aisle (under the green canvas) and one row of boxes with potatoes on each side of the aisle. An indent in the canvas can be observed because of the low pressure underneath it.

View from above the boxes, where the spacing between two suction aisles can be noted. It is also important to note that the boxes should be full, otherwise the air will pass over the produce.

How does a storage system with a suction wall and boxes function?

The suction wall has vertical hatches, which are about 40 cm wide. The number of hatches will depend on how many boxes can be stacked on top of each other in a storage facility. At both sides of the vertical hatches, the boxes are stacked in such a way that they form an aisle in between. This aisle is covered by a tarpaulin or canvas, so the aisle becomes part of the low pressure behind the suction wall. As seen in the image, the air is forced through the produce. This system gives a very homogeneous airflow through the produce.

This system requires storage boxes that have sides with slits, to enable the air to pass through.

It is very important that all boxes are filled completely. A half-filled box will cause serious loss in ventilation capacity, because the air will be sucked, un-hindered, over the produce in the half-filled box.

A storage system with forced ventilation using a suction wall

To see more details regarding the major components of a storage system, like: sensors, the Multiserver (the brain of the system), boxes to be used etc., please go to: Components of a computerised storage facility.

Boxes in a potato storage facility with a suction wall