Fans and Motors

Pipe Diameter (in)Cross1Area (ft2)Airflow (cfm)2
@1500ft/min@2000ft/min@3000ft/min
50.14210280420
60.20300400600
70.27405540805
80.355257001050
90.446608801320
100.5582511001650
110.6699013201880
120.79118515802370
130.92138018402760
141.07160521403210
151.23184524603690
161.40210028004200
171.58237031604740
181.77265535405310
191.97295539405910
202.18327043606540
212.40360048007200
222.64396052807920
232.88432057608640
243.14471062809420
253.415115382010230
263.695535738011070
273.975955794011901
284.276405854012810
294.586870916013740
304.917365982014730
1. Cross sectional area of inside air duct, not necessarily circular.
2. Airflow through duct in cfm = A x v
Table 3. Airflow rates for selected air velocities and duct across sectional areas.

Most aeration systems are designed with downward airflow through the cottonseed. This helps minimize moisture condensation and accumulation in the top layers of cottonseed, which can occur when warm, moist air moves upward into the cold top layers of seed. In addition, temperature and odor of the exhaust air from the fan can give an indication of cottonseed condition.

To select a fan, the required volume of air to aerate the number of tons of seed must be known as well as the static pressure. Static pressure or resistance to air flow is measured in inches of water and depends on the depth and density of the seed. Static pressures for different airflow rates and cottonseed depths are shown in Table 3. Knowing airflow and static pressure, a fan and motor can be selected from a supplier's catalog to meet the design specifications.

 

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