World Grain -- December 2015 - 74

FEED OPERATIONS

Bucket elevator selection
and installation tips
Location of the bucket elevator and the atmosphere in which
it operates will impact the choice of construction
by Fred Fairchild

Bucket elevators are the most common method of elevating grains and other products. In this article we will examine issues relating to the selection of bucket elevators as
well as tips for installation.
The decision involves selecting the type of bucket elevator to be used and how it is built. Unless the elevator is of
small capacity and meets other requirements, it is recommended that the elevator be located outside of any structure
if it conveys combustible material such as whole or ground
grains or grain dust. OSHA rules in the United States do allow the bottom (boot) section to be located inside as long as
most of the bucket elevator is outside the structure. There
are many safety devices and types of construction required
and we will cover safety devices in a future article.
The bucket elevator commonly used in the grain-related
industries is a continuous belt with open top cups installed
on it that discharge over a top pulley using centrifugal force.
It is composed of three major components: the boot section
(base or bottom), trunking (the enclosure that surrounds the
ascending and descending belt with its cups), and the head
section where the product is discharged.
The location of the bucket elevator and the atmosphere in
which it operates will affect the choice of construction. If
installed in an area not subject to damp or multiple climatic
changes, the painted steel ones will work. Bucket elevators made of painted steel and installed in areas such as
outdoors will require repainting after a few years to protect
the metal. The cost of the painting may be as much as the
difference in cost to use galvanized construction initially.
For elevators handling acidic or corrosive products, stainless steel construction may be needed for the unit to last a
reasonable lifetime.
74

A comparison of estimated costs for a bucket elevator
with a capacity of 7,150 cubic feet (160 tons) per hour of
shelled corn at 45 pounds per cubic foot with a discharge
height of 100 feet is shown in Table 1 (page 76). The table
includes the elevator, a 25-horsepower motor and drive,
and the belts and cups for a complete bucket elevator.
INSTALLATION CONSIDERATIONS
Careful consideration must be exercised in initial purchasing of a bucket elevator for long lifetime installation.
When installing a bucket elevator, it should be set on a
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the bottom above areas where water might accumulate.
This is especially true in below ground pits that normally
are damp or wet. The bottom (boot) section of a standard
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to the area where the elevator cups can scoop the product.
This product residue is there from the time the empty boot
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If no product residue can be allowed or tolerated, the use
of a round bottom self-cleaning boot design is necessary.
I recommend that standard boots be supported on a structure 12 to 18 inches above the mounting pad. This allows
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slide that will aid in dropping the residue out of the boot
section and makes it easier to clean out.
Belt tension is adjusted by tightening the pull on the belt.
This is done by moving the pulley in the boot section down.
Thus the boot is equipped with manual or powered adjustment to raise and lower the boot pulley. When the bucket
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December 2015 / World Grain / www.World-Grain.com

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