5. Material Handling
“the art and science of moving, packaging, and sorting of substances in any
form.
mechanical equipment used for the movement, storage, control and
protection of materials, goods and products throughout the process of
manufacturing, distribution, consumption and disposal.
used to create time and place utility through the handling, storage, and
control of material, as distinct from manufacturing,
7. Conveyors
- It is a horizontal, or vertical device for moving or transporting bulk materials or objects in a
path predetermined by the design of the device and having points of loading and discharge
fixed.
- quick and efficient transportation for a wide variety of materials
Conveyors are used:
- When material is to be moved frequently between specific points.
- To move materials over a fixed path.
- When there is a sufficient flow volume to justify the fixed conveyor investment.
Conveyors can be classified in different ways:
- Type of product being handled: unit load or bulk load
- Location of the conveyor: overhead, on-floor, or in-floor
- Whether or not loads can accumulate on the conveyor
11. 1 Main Principle and Advantages
2 Main Application
3 Types of Vibratory conveyors
12. Main Principle
- The basic vibratory (or oscillatory) conveyor consists of a trough which is supported
on or suspended by springs or hinged links and caused to oscillate at high frequency
and with small amplitude by an appropriate drive mechanism.
- Using vibrations for transferring the material. it provides an efficient and economical
method of conveying or processing bulk materials.
13. - The fundamental action of the vibrating trough on the bulk material carried in it is to throw the
particles upward and forward so that they advance along the trough in a series of short hops.
14. Advantages
- Low maintenance drive.
- High material conveying capacity
- Able to be used with a wide range of products
- they do not require any spare parts to replace
- conveying rate is much more faster than belt conveyors, thus increasing the production
capacity.
- Choice of Open thru or Tubular design
- the material is “live” and moves independently of the conveying medium
require minimum maintenance
- Extremely hot materials can be handled
15. Main Application
- Vibratory conveyors are especially amenable to adaptations which allow some kind of processing
operation (such as screening, de-watering, separate, cooling or drying) to be undertaken while the
product is being transported.
- Feeding mineral ores or quarried stone, to a primary, secondary, or tertiary crusher
- transportation of dusty, hot, toxic, and chemically aggressive bulk material
- delivery of small machine parts like screws, rivets
- Feeder/ conveyor for furnace charging to clinker removal.
- Feeder for conveyor belt padding and crusher load control.
- Feeders for packaging, blending, batching, mixing, flaking, freezing and drying operations.
16. Types of Vibratory conveyors
1- Horizontal Single Drive.
Used to :
Conveying flakes, blended materials, and coated products
Scanning product.
- Quick and easy to clean
- It reduces material damage, coating loss, segregation, and stratification
17. 2- Horizontal Cooling.
- The Vibrating Cooler is utilized for transferring and cooling in the recycling process of old sand
from casting. It can achieve the goal of drying and cooling continuously.
18. 3-Tubular Horizontal.
- These conveyors are ideal for the transfer of all granular and powder products.
- can help move dusty, abrasive, messy or dangerous substances cleanly, safely and efficiently.
- Used in a variety of fields such as food, chemical-technical and pharmaceutical industries,
where a gentle conveying and closed sanitary is needed.
19. 4- Spiral Vibrating Conveyor.
- spiral conveyors designed as natural-frequency system that operates with a large vibration
amplitude and a low vibration frequency.
- Low work space with more efficiency
21. Feeder and conveyors
- although the distinction is in fact mainly one of application. An important aspect of vibratory
handling is the ease with which the flow rate of the conveyed product along the trough can be
adjusted by altering the amplitude and/or the frequency of the vibration.
- Feeder must be capable of operating under varying head-loads, whereas a conveyor requires a
regulated feed rate and should not be subjected to changes in head-load.
22. Drive Mechanisms
Electromagnetic driveEccentric-mass
mechanical
Positive mechanical Hydraulically
Drive is on the longer
heavy-duty conveyors
where low-frequency
high-amplitude
oscillation is appropriate.
Positive drive can be in:
a- Simple direct drive
b- Resonance-type
conveyor
c- Balanced conveyor
using a split trough.
1. Caused to vibrate
using a single rotating
eccentric mass.
2. Much more common
approach is to use two
contra-rotating masses of
equal size.
3. The chief advantage is
the resulting linear
oscillating force can be
relatively easily adjusted
for direction.
1. One part being
mounted on the supporting
framework and the other
on the oscillating trough.
2. This drive mechanism
relies on the cyclic
energization of one or
more electromagnets to
generate the vibratory
motion of the trough.
3. In most designs there is
no contact between the
parts of the electromagnet
- Similar to
electromagnetic drives but
it is capable in general of
heavier-duty work.
1. Pneumatic or hydraulic
receiver pistons fitted to the
conveying trough can be
driven by a remotely
situated pump unit.
2. Also, capacity control of
the conveyor can be readily
achieved using manual or
automatic pressure control
valves on the pneumatic or
hydraulic supply.
23. Force analysis
- Throw number
- Machine number
- Drive angel
- efficiency of transport
- Material transport velocity
- Solids mass flow rate
24. Throw number (ᴦ)
- therefore the ratio of the vertical acceleration of the trough to the gravitational
acceleration g.
- normally be determined at the design stage by chosen values of frequency,
amplitude and angle of oscillation
- At the start of the flight phase YT/g = - 1, and it follows that, if the positive value
of r is less than unity, the bulk solid will not leave the surface of the trough and
forward movement will be little
25. Dynamic machine coefficient [K]
- The relationship between amplitude and frequency expressed by [K] and can be
represented graphically by curves.
- in practice vibratory conveyors are usually designed to have K between 1 and 4.
26. Drive angel (β)
- The angle of oscillation' or drive angel between line of action and horizontal trough.
- Optimum values of the drive angle β, for greatest transport rate, are plotted against
the dynamic material coefficient ᴦ, and from this chart it is seen that β is likely to be in
the range 30° to 50°.
27. efficiency of transport (ηu)
- It is found to be a function of the dynamic material coefficient ᴦ, the vibration angle β
and the coefficient of friction ηϝ between the bulk solid and the surface of the trough.
- Also depend upon a number of other variables, such as the depth of the bulk solid
layer on the trough, and the inclination of the trough (if not horizontal).
28. Material transport velocity (Us)
Us = ηu* λ*cosβ*2πf
- Since the actual velocity of the particles in the trough will vary throughout each cycle,
it is the average conveying velocity that is of significance.
29. Solids mass flow rate (ṁ)
- can then be predicted by introducing the cross-sectional area of the bulk material in
the trough and its bulk density.
ṁ = ρ A Us