Important Bucket Elevator Formulas

TO FIND LEG CAPACITY:

1. DETERMINE BELT SPEED IN FEET PER MINUTE

a. Motor RPM x motor pulley diameter, divided by driven pulley diameter = Input shaft speed to drive.

b. Divide Input shaft speed by Drive reduction ratio (15:1, 25:1, etc.) This gives the head shaft RPM.

c. Multiply the head shaft RPM x head pulley diameter in feet, x

3.1416. This gives the Belt speed in feet per minute.

2. FIND THE NUMBER OF CUPS FILLED IN ONE MINUTE:

a. Multiply feet per minute of belt speed x 12”, divided by cup spacing in inches.

b. Find cup capacity from Manufacturer’s chart in cubic feet.

Use water level + 10% or 75% of gross cup capacity.

c. Multiply cups filled per minute x cup capacity in cubic ft. This gives capacity of leg in one minute. Multiply result x 60 minutes

for hourly capacity in cubic feet.

d. For Bushels per hour, multiply cubic ft. per hour x .8

HORSEPOWER FORMULA FOR BUCKET ELEVATORS:

1. DISCHARGE HEIGHT IN FEET X BUSHELS PER HOUR,

Divided by 33,000 gives BARE HORSEPOWER

2. Multiply Bare Horsepower x 1.25 (safety factor) to get DESIGN

HORSEPOWER.

3. This calculation is based on grain weighing 60# per bushel.

ALTERNATE HORSEPOWER FORMULA:

1. Multiply DISCHARGE HEIGHT IN FEET X POUNDS OF MATERIAL

RAISED IN 1 MINUTE. Divided by 33,000 gives BARE HORSEPOWER.

2. Multiply Bare Horsepower by 1.25 (Safety Factor) for DESIGN

HORSEPOWER.