Storage, cleaning and preparation in grain production

There are many different varieties of wheat that are used to make flour. In general, wheat is either hard (containing 11-18% protein) or soft (containing 8-11% protein). The flour used to bake bread is made from hard wheat. The high percentage of protein in hard wheat means the dough will have more gluten, allowing it to rise more than it would with the soft wheat. The flour used to bake cakes and pastry is made from soft wheat. Then there is an ‘all-purpose’ flour, made from a blend of soft and hard wheat. Before wheat can be ground into flour it must be free from foreign matter. This requires several different cleaning processes. The first device used to purify wheat is known as a separator. The wheat then passes through an aspirator. This device works like a vacuum cleaner, and it extracts the foreign matter that is lighter than the wheat. The next stage is ‘cold conditioning’ which involves soaking the wheat in cold water. An alternative is ‘warm conditioning’, which involves soaking the wheat in water at a temperature of 115°F (46°C).

The OPTIWAVE 6500 radar level transmitter is the most suitable device for level measurement in the large grain storage silos, which can be as large as 80m or more. The level meter is unaffected by dust and temperature. The OPTITEMP is a suitable temperature transmitter to monitor the grain in these silos. During the conditioning phases the level of water in the storage tank can be controlled with OPTISWITCH 6500 level sensors, and the flow economically monitored by the WATERFLUX 3300 electromagnetic flowmeter.