Building a Rice Drying Hut
A rice drying hut helps farmers reduces yield losses and preserves the quality of the rice. It is a low-cost technology which is easy to apply, and well suited to small-scale farmers.
Building the Hut
Materials
To build the hut, you will need some strong bamboos or small logs, some large transparent plastic sheets, a nylon net, some wire and some rice husk (Fig. 1).
Building Method
- The size of the hut depends on the available land surface, but usually it will cover an area of 100 - 300 square meters, and be 5 to 10 meters long. Prepare the floor so it is flat and smooth.
- Dig a drainage gutter around the floor. It should be 20 - 30 cm wide, and 20 - 30 cm deep.
- Erect a row of bamboos or logs as support columns in the middle of floor, connected at the top by a log or bamboo as a roof beam.
- The columns should be about 2 - 3 meter high, with an extra 50 cm buried in the soil.
- Small rafters are fastened to the roof beam at one end, with the other end of each rafter resting on the ground. This makes a V-shaped structure.
- Nylon ropes are stretched over the roof beam of the hut from one side to the other. The ropes should be 50 - 60 cm apart.
- Plastic sheets are put over the ropes, to make a V-shaped roof. The lower part of the roof should be 20 - 30 cm above the ground surface, so that water will flow easily into the gutter.
- The four corners of each plastic sheet are fastened to a nylon rope.
- Dry rice husk is spread over the floor to a depth of 5 - 10 cm. The nylon net is laid over the husk, and fixed to the ground with bamboo pegs at the edtes.
Drying the Rice
The harvested rice is spread out evenly over the nylon net (Fig. 2). The husk beneath the net insulates the rice from the wet ground, and gives the rice at the bottom a good supply of dry air.
The pile of rice is 20 - 30 cm deep in the middle, and 15 cm deep at the edges. Regularly once an hour, the rice should be turned and piled into long ridges.
The rice will take from one to three days to dry, depending on the weather. If the rice in the hut is still too wet and the sun has come out, some of the plastic sheets should be removed from the roof, to allow the sunlight to enter and to get rid of some of the moisture.
Some Characteristics of the Rice Drying Hut
The temperature inside the hut is always higher than the temperature outside it. Because the temperature inside the hut rises gradually, there is also a gradual loss of moisture from the rice grains, so the rice grains seldom crack.
On sunny mornings, between 9 AM and 10 AM, it is 8oC warmer inside the hut than outside it. An hour later, the temperature difference rises to 12oC. On rainy days, the difference is 6oC. At night, the difference is 1-3oC.
A hut measuring 10 x 10 meters (i.e. 100 m2) has the capacity to dry 2 - 2.5 mt of rice at any one time. Usually, the hut is used to dry several batches of rice, one after the other.
Precautions
The hut must be protected from wind, and should stand with one side facing the direction of the prevailing wind. The entrance should not face into the prevailing wind, and rain should not be able to blow into the hut.
Index of Images
Figure 1 Building the Rice Drying Hut
Figure 2 Spreading Out the Rice in the Rice Hut
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