Screw Conveyor Power Calculation

Screw Conveyor Power Formula:

\[ HP = \frac{L \times W \times F \times RPM}{33,000 \times Eff} \]

Length (L):

Weight (W):

lb/ft

Factor (F):

RPM:

rev/min

Efficiency (Eff):

Required Power (HP):

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1. What is Screw Conveyor Power Calculation?

The screw conveyor power calculation determines the horsepower required to drive a screw conveyor system based on length, material weight, friction factor, rotational speed, and mechanical efficiency. This calculation is essential for proper motor selection and system design.

2. How Does the Calculator Work?

The calculator uses the screw conveyor power formula:

\[ HP = \frac{L \times W \times F \times RPM}{33,000 \times Eff} \]

Where:

\( HP \) — Horsepower required
\( L \) — Length of conveyor (feet)
\( W \) — Weight of material per foot (lb/ft)
\( F \) — Material factor (dimensionless)
\( RPM \) — Rotational speed (revolutions per minute)
\( Eff \) — Mechanical efficiency (percentage)
\( 33,000 \) — Conversion constant (ft-lb/min per horsepower)

Explanation: The formula calculates the power needed to overcome friction and move material through the conveyor system, accounting for mechanical losses through the efficiency factor.

3. Importance of Power Calculation

Details: Accurate power calculation ensures proper motor sizing, prevents underpowering (which can cause system failure) or overpowering (which wastes energy and increases costs), and optimizes system performance and reliability.

4. Using the Calculator

Tips: Enter conveyor length in feet, material weight in pounds per foot, appropriate material factor (typically 1.0-4.0), rotational speed in RPM, and mechanical efficiency as a percentage. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical material factor (F) range?
A: Material factors typically range from 1.0 for light, free-flowing materials to 4.0 for heavy, abrasive materials. Consult material handling references for specific values.

Q2: What mechanical efficiency should I use?
A: Typical mechanical efficiency ranges from 85% to 95% for well-maintained systems. Use lower values for older equipment or systems with multiple drive components.

Q3: Does this account for incline or decline angles?
A: No, this basic formula assumes horizontal operation. For inclined conveyors, additional calculations for elevation changes are required.

Q4: How do I determine material weight per foot?
A: Calculate based on material density and conveyor capacity: W = (material density × conveyor capacity) / (conveyor speed × cross-sectional area).

Q5: Should I add a safety factor to the calculated power?
A: Yes, it's recommended to add 10-20% safety factor to the calculated horsepower to account for startup loads, material variations, and future capacity increases.