45
Air near bin wall cools and sinks to bottom of bin, pushing air up in center. When grain near surface cools warmer
air, moisture condenses because cool air cannot hold as much moisture as warm air. As this circulation
continues, moisture begins to accumulate near top center of bin (as shown in
) and crusting may occur,
indicating moisture accumulation and mold growth. An aeration system will cool grain uniformly, limiting moisture
migration. In spring and summer months when outside air warms up, moisture migration may occur in opposite
way and moisture will accumulate at bottom of bin.
Sukup Manufacturing Co. recommends the following steps for proper grain storage:
Transitions
must be properly sealed at both ends to prevent air loss. Air and pressure loss may occur with
improper installation. Outlet area of transition must be adequate for airflow produced by fan. Also, transition
shape should provide a smooth airflow route without any abrupt direction changes. If any bin stiffeners need
to be cut to install transition, suitable alternative support must be provided to prevent bin wall collapse.
Cleaning grain
before storage screens fines, foreign material and broken kernels and improves its storability.
Select a grain cleaner that collects and conveys screenings away. The most common locations for cleaners
are at receiving, after dryer and just before delivery to storage, and at loadout. Cleaning is easiest at low-flow
rates. Coring bin will also remove a major portion of fines and foreign material.
Roof vents
ensure proper airflow while preventing rain and snow from entering the bin. Roof vents also
increase efficiency of aeration systems and should always be used in drying. Without adequate open area to
let air and moisture out of the bin (1 ft² [.093 m²] of opening for every 1500 CFM [2550 m³/hr] fan will
produce), aeration or drying system will not operate efficiently. Have at least 1½” (38.1 mm) eave opening.
Also, keep center cap and manhole open during cooling and drying but closed during storage. Roof vents
need to be cleaned of dust and debris after each season to prevent roof damage.
Grain Spreaders
provide a more level grain surface in bin and are available for bins of up to 60’ diameter.
Peaked grain results in increased airflow resistance in peak of bin. Furthermore, fines and foreign material in
grain tend to gather in center of bin. These fines also increase airflow resistance.
Figure 50 -
Effect of Spreaders on Peaked Grain
Properly adjusted and operated grain spreaders will leave top surface of grain level and fines and foreign
material more evenly distributed throughout grain mass. A level surface and more evenly distributed fine
material result in uniform airflow resistance throughout entire bin, as shown in
III.
Aeration
Aeration’s purpose is to move air through grain in order to maintain a uniform temperature in bin and prevent hot
spots that accelerate spoilage. Since most problems develop in center of bin and crop will cool naturally near walls,
aeration system must at least provide good airflow in bin center.
Ideally, a fully perforated floor is used, but aeration ducts may be used for structures storing only cool, dry grain. If
aeration ducts placed directly on floor are to be held in place by grain, ensure grain is directly on top of ducts to
prevent movement and damage to them. Ducts must be strong enough to support grain regardless of its shape or
material used. Ensure airflow rate for aeration is 1/20 to 1/5 CFM/Bu (usually 1/10) or 4 to 15 m³/hr/MT (usually 8).
Summary of Contents for Fastir
Page 4: ...Limited Warranty 4 LIMITED WARRANTY...
Page 50: ...Appendix A Wiring Diagrams 50 Figure 52 Double Auger Fastir Wiring Diagram...
Page 51: ...Appendix A Wiring Diagrams 51 Figure 53 Triple Auger Fastir Wiring Diagram...
Page 52: ...Appendix A Wiring Diagrams 52 Figure 54 Quadruple Auger Fastir Wiring Diagram...
