hine shaft with centering DS form with thread acc B4-CV7A Bevel-helical gearboxes B4

Flender/Flender Gear Units/Bevel-helical gearboxes B4

The mean residence time of particles in the bed is 2 min (. 5 RADIATION DRYING The electromagnetic radiation, with wavelengths ranging between 0.2 and 0.2 , is used for the drying of different materials. The radiation sources include solar, infrared,dielectric, and microwave. The solar spectrum of radiation (0.2.5 ) does not pene- trate the skin of the materials. The magnitude of absorbed radiation depends primarily on the average radiative properties of the materials, direction of incidence, and the wavelength of the radiation. Infrared radiation (4- 8- band) can penetrate to certain depth in the material, and the drying of coatings, thin sheet, and lms is generally accomplished bythis spectrum of radiation. The radio frequencies are used to heat some moist solids volu-metrically by reducing the internal resistance to heat transfer, and the energy is absorbedselectively by the water (for its high dielectric value) molecules within the materials. Because of involvement of high cost, this method of drying is useful for drying high-unit value products or removal of nal moisture content of the products, which is generally nototherwise possible with other drying systems. 5.1 Sun Drying major quantity of grain is still dried under the sun in most of the Third World countries. This drying system can be classied into three categories: drying of standing crops, drying of grains in stalk, and drying of threshed grains, as described in the following sections. 5.1.1 Drying of Standing Crops The grains are dried on the standing crops until they attain proper moisture content. They are harvested and threshed thereafter. Besides considerable quantity of shattering loss of grains, this slow-drying process takes about 2 weeks after the grains attain maturity. Development of sun checks is common phenomenon that is attributed to uctuation oftemperature and relative humidity of the ambient air during day- and nighttime. Thus, ahigh yield of broken product is obtained during mi