Bucket elevator

that is an assignment that contains bucket elevator function, construction,types and uses

1. Function of Bucket Elevator
tilting mechanism & its uses
Assignment # 2
That assignment of subject of Material Handling that contains function of bucket elevators with its
working principles tilting mechanism. with advantages and usage of these elevators
11/12/2015
SUBMITTED BY:
MUDDASSAR LATIF AWAN (BSMT01123085)
SUBMITTED TO :
Mr. ARSHAD CHOUDRY

2. Bucket Elevators

A bucket elevator, also called a grain leg, is a mechanism for hauling flow able bulk materials
(most often grain or fertilizer) vertically.
It consists of:
1. Buckets to contain the material;
2. A belt to carry the buckets and transmit the pull;
3. Means to drive the belt;
4. Accessories for loading the buckets or picking up the material, for receiving the
discharged material, for maintaining the belt tension and for enclosing and protecting the
elevator.
A bucket elevator can elevate a variety of bulk materials from light to heavy and from fine to
large lumps.
A centrifugal discharge elevator may be vertical or inclined. Vertical elevators depend entirely
on the action of centrifugal force to get the material into the discharge chute and must be run at
speeds relatively high. Inclined elevators with buckets spaced apart or set close together may
have the discharge chute set partly under the head pulley. Since they don't depend entirely on the
centrifugal force to put the material into the chute, the speed may be relatively lower.


Nearly all centrifugal discharge elevators have spaced
buckets with rounded bottoms. They pick up their load
from a boot, a pit, or a pile of material at the foot pulley.
The buckets can be also triangular in cross section and set
close to on the belt with little or no clearance between
them. This is a continuous bucket elevator. Its main use is
to carry difficult materials at slow speed.
Early bucket elevators used a flat chain with small, steel
buckets attached every few inches. Current construction
uses a rubber belt with plastic buckets. Pulleys several feet
in diameter are used at the top and bottom. The top pulley
is driven by an electric motor.

It is useful in oil mill machinery and consists of buckets, a
belt, to carry the buckets and transmit the pull, machine to
drive the belt and accessories for loading the buckets or

3. picking up the material. it is important accessory for oil mill machinery as it can convey light to
heavy materials at ease.
Bucket Elevators are one of the most popular systems in use today for elevating bulk materials.
Their inherent simplicity makes them a popular choice for handling bulk materials and in
processing applications. Continuous developments in bucket shape, head and boot profiles,
manufacturing and operating specifications.
With a bucket elevator, most free flowing materials and other materials with poor flow
characteristics can be successfully handled. The rate at which material can be elevated depends
on many factors in addition to the obvious effects of bucket design, capacity and speed.

Working Principle

The product is fed into the moving bucket belt at a controlled rate in a similar manner to feeding
a normal belt conveyor. At the end of the conveyor, the buckets are emptied by gravity into the
discharge section.

Function

The main function of the bucket elevator is to transport or elevate goods and materials from one
place to another quickly and easily. The buckets are connected to a chain or belt which moves
when the equipment starts to function. The contents of the bucket are moved from one location
to another when the belt moves. The belt is either chain driven or friction driven.
In the mining industries, these buckets are filled with ore which is moved vertically and then
poured or dumped to a new location. Ore is a heavy material and therefore the bucket should be
constructed with heavy materials such as metals. Metallic buckets are quite commonly used in
most of the industries as it is durable and tensile, suitable for various purposes.
One of the main functions of the bucket elevator is to elevate the goods in the bucket in a vertical
direction. The products in the buckets are raised or lowered and the contents are dropped to
another container. The entire process of raising and lowering is done with the help of mechanical
and hydraulic power.
Another function of the bucket elevator is transporting the bucket in a horizontal direction. The
materials are moved or transported from one place to another with the help of these elevators.

Construction
Belt Buckets: The robust thick-walled plastic or steel buckets running between the parallel
rubber chains are joined with flexible bucket strips to create a closed, gap-free and resilient
conveying system.

4. Feed section: Depending on the application continuous bucket conveyor is equipped with one or
more in-feeds. The length of the feed opening is variable to suit the application, although the
width is related to the bucket size. At the in-feed, the product is fed into the buckets from the top
at a controlled rate. Appropriate equipment can be supplied to provide a controlled rate of feed.
The feed opening is sealed to the bucket belt.
Discharge section: Continuous bucket conveyors have just one discharge section. The length of
discharge will be determined by the discharge characteristics of the product. A bucket knocker
can assist product discharge from the buckets. Discharge chutes complete the connection to silos,
packaging machines or other equipment in the production line. The drive is mounted in the
discharge section. A gear motor is either directly connected to the drive shaft or via a
transmission chain. On the opposite side of the drive shaft a backstop bearing prevents the bucket
belt from running back.
Spillage: Continuous bucket conveyors can be supplied in a self-cleaning version: any product
spillage in the bottom horizontal section is collected by the return strand of buckets and returned
to the process. Alternatively, cleaning drawers, mesh or hinged bottom panels can be supplied.

Types of bucket elevators

The most common elevator is a centrifugal discharge
elevator, which may be vertical or inclined. The action of
centrifugal force drives the vertical elevators to put the oil
into the discharge chute and be run at a relatively high
speed. Inclined elevators have the buckets placed little
apart or set close together may have the discharge chute
set partly under the head pulley. The speed of the inclined
elevator is low because it doesn't depend on the
centrifugal force.
All vertical elevators have spaced buckets with rounded
bottoms. The materials from a boot, a pit or a pile can be
easily loaded to a centrifugal elevator. The shape of
buckets is triangular and close to on the belt with little or
no space in between them. These types of elevator are
being used to carry heavy material, and lift at a slow pace.
Unlike earlier elevators, which used to use small, flat steel
buckets, nowadays modern elevators uses a rubber belt
with plastic bucket. These are more convenient and easy
to use. Further, the pulleys are being used at the top and bottom and driven by an electric.

5. There are three common bucket elevator designs seen in bulk material handling facilities
worldwide:
1) Centrifugal Discharge Elevator - Typically, this is the style of elevator used in grain
handling facilities we are all familiar with along rivers, ports or on the farm. The elevator
buckets discharge product freely by the use of centrifugal force
2) Continuous Discharge Elevator - This style bucket elevator is used typically to discharge
sluggish and non-free flowing product where the elevator buckets discharge on top of each other.
Speeds are run in the 125 fpm range to accomplish this type of centrifugal force
3) Positive Discharge Elevator - Elevator design where the buckets are used to elevate
commodities such as popcorn, candy and potato chips where the utmost concern is on gentle
handling and finished food grade applications. This style elevator bucket operates off a double
strand chain where they are held in place by two pins so the bucket is allowed to freely swivel.

Advantages
The bucket elevators are used in most of the industries today for a variety of purposes. It has a
huge transporting capacity with lower maintenance and better transportation facilities.
These elevators are durable with low driving power. With the help of elevators, goods and
materials can be transported smoothly and easily. Materials can be lifted to a great height with
the help of these elevators. In addition to reliability, the bucket elevators have a wide range of
lifting capabilities. Modern elevators use plastic buckets and rubber belts for better and efficient
functioning.

1. Used in Number of Industries
2. Large Conveying Capacity
3. High Hoisting Height
4. Smooth Transportation of Goods
5. Less Maintenance
6. Stable and Reliable Running
7. Long Service Life
8. Low Driving Power
9. Wide Range of Lifting


Industries served that
Rely on Bucket elevators

Industries are ………. Grain Industry, Cement industry, Fertilizer & Mining, Aggregate/Asphalt/concrete
equipment, Lifting and material handling equipment etc.
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