H4DH-14-C even by precise align ment Furthermore because Helical gear Reduction Box H4

Flender/Flender Gear Units/Helical gear Reduction Box H4

ilating with air heated to 4 (7F) above ambient through duct system or through one centrally placed cylinder, as with batch drying. This method is adequate for bins having capacities of up to 1 ton(. This method usually requires continuous operation of the ventilation system over period of 1 weeks, but has the advantage of permitting the handling of huge amounts in one ll. In-storage drying may also be carried out on bar oor provided with fan capable of providing airow rates of 8 3h/H1ton/H1of grain and an appropriate system of oor and lateral ducts. The advantages of this method are low-cost and simplicity. 2.4 Multistage Drying The term multistage drying refers to any process that uses high-temperature drying in combination with aeration or natural air drying. An outline of two such processes, dryera-tion and combination drying, follows. 2.4.1 Dryeration Dryeration is two-stage process by which grain is dried in heated air dryer to within about 2% of its dry moisture content and then moved to an aerating bin where it isleft to steep without ventilation for about 1 (. This allows time for moisture to migrateto the surface of the kernel. The grain is then aerated for about 1 at airow rates onthe order of 2 3h/H1m/H1of grain (0.5 cfm/bu). 1 Raghavan The advantages of this process are 1. Higher drying temperatures can be used during the removal of most of the mois- ture, as the residence time is shorter, which improves the speed of the initialdrying. 2. The drying system capacity can increase by up to 6% because the initial drying is faster, and there is no residence time for cooling. 3. The last few moisture percentage points, which are the most difcult to remove efciently, require only energy for the blower because the heat already con-tained within the grain is sufcient to drive the moisture to the surface, resultingin fuel savings of 2% or more. 4. The grain quality is improved by slower cooling, which results in fewer heat stress cracks. If the air