Situation – Grain Systems PNEG-501 User Manual
Page 11
11
Fan/Heater Application
SITUATION
SITUATION:
On farm in-bin drying of corn, 24' diameter, 6 ring, FCDL series farm bin with
22' eave height. Tank will be layer filled to level full. The drying systems
will consist of a full floor with 12" plenum, stirring device, one fan and heater.
1.
AVE GRAIN DEPTH, level = (6 rings x 3.67) - 1 (floor) - 2 (stirring
device) = 19'.
2.
Select 1 CFM/BU for heated air drying of corn.
3.
From the STATIC PRESSURE TABLE for corn at 19' and 1cfm/bu the
static pressure is 3.58" of water.
3.58" water column
4.
Bin operating capacity, BUSHELS
19' x 0.6594 x 24 x 24 = 7216
5.
Required TOTAL AIRFLOW, CFM
1 cfm/bu x 7216 bu = 7216 CFM
6.
From the FAN PERFORMANCE TABLE for van axial fans, at 3.58" static
pressure (4" on table) and 7216 cfm (10250 on table), the best choice would
be one 15 hp 26" fan.
7.
Number of ROOF VENTS
10250 cfm ÷ 1800 cfm/vent = 5.6, therefore 6 vents
NOTE!
It may be desired to increase the number of roof vents in a
drying situation to account for layers or batches as the effective
airflow will increase. In this example 8 vents should
accommodate the airflow at one-half the expected pressure:
12700÷1800 = 7
*
Two fan/heater sets may be necessary to meet temperature requirements.
Two fan/heater sets may also be necessary to provide even air/heat distribution
when recirculating devices are in use.