ELEVATOR

A bucket elevator is a type of material handling equipment designed for the vertical transport of bulk materials. It uses a series of buckets attached to a belt or chain to move materials, such as grains, minerals, or other loose materials, up a vertical path. Bucket elevators are commonly found in industries like agriculture, mining, cement, food processing, and chemical production due to their efficiency in moving materials to different heights quickly and consistently.

This dataset and calculations are for educational purposes only using Discrete Element Analysis (DEM).

Problem definition

To determine the optimal trajectory/discharge angle of material and design a suitable bucket shape for a bucket elevator to ensure complete, controlled, and efficient unloading of materials at the discharge point.

First Iteration:

RPM : 90

Pulley Diameter : 12"

Height: 132"

Particle Size: 5 cm (Polyhedron)

Normal Force: Hysteretic Linear Spring

Tangential Force: Linear Spring Coulomb Limit

Determine the Trajectory/Discharge Angle:

Establish a method to calculate the trajectory angle at which material exits the bucket under centrifugal force. The angle should account for:

Bucket speed (elevator RPM or angular velocity in radians per second).
Material properties, such as particle size, density, and flowability.
Geometry of the bucket (depth, lip angle, width, and curvature).
Position of the discharge chute relative to the bucket’s trajectory.

Particle distribution

First, we need to use a single bucket to analyze the trajectory of particles both at the scooping point and at the discharge point using the particle's material.

Spillage during the scooping due to rotational and translational force of the bucket motion.

Bucket Particle's Residence Time

discharge point

Calculating the trajectory angle at elevator speed based on material characteristics. We expect materials to be discharged at approximately 170 degrees from the 0-degree horizontal. However, due to the speed or the bucket orientation, materials remain held in the bucket until nearly 180 degrees of rotation.

Bucket Particle's Trajectory at discharge point showing the material’s weight and flowability affect the angle and speed at which it is discharged. Note that this is the first iteration to check the angle of discharge. Based on the figure above, we need to redesign the bucket position or the bucket shape to achieve the desired angle.

Final design using DIN 15234 dimensions with periodic bucket replication.

Available vendor selection chart based on the requirement . Continuous discharge elevators are offered as: Boot take-up. This elevator is available with buckets continuous mounted on chain or belt to handle many bulk materials ranging from light to heavy and from fines to larger lumps.

The buckets are loaded by direct feeding with the use of a loading leg. Spillage of material is minimizing by the close bucket spacing. As buckets discharge, material flows over thepreceding buckets; projecting sides form a chute, assisting in proper discharge. Q.E.D.

AnimationReference used in this calculation:

youtube.com/shorts/o40mUXdJyro?feature=share

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