1. Introduction
Conveyors are one of the transport equipment in material handling
Transport equipment
Conveyors
Cranes
Industrial Trucks

2. Conveyors are used
Where 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 conveyer investment

3. Classification of conveyors
Type of product being handled unit
bulk
Location of the conveyor overhead
on-floor
in-floor
Whether or not loads can accumulate on the conveyor
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4. Type of Conveyors 1. Chute Conveyors 2. Wheel Conveyors
3. Roller Conveyors
a) Gravity roller conveyor
b) Live (powered) conveyor
4. Chain Conveyors
5.Slat Conveyors
6.Belt Conveyors
a) Flat belt conveyor
b) Magnetic belt conveyor
c) Trough belt conveyor

5. 7.Bucket Conveyors
8. Vibrating Conveyors
9. Screw Conveyors
10. Pneumatic Conveyors
a) Dilute-phase pneumatic conveyors
b) Carrier-system pneumatic conveyors
11. Vertical Conveyors
a) Vertical lift conveyors
b) Reciprocating vertical conveyor

6. c) Sliding shoe device 12. Cart-on-track conveyors 13. Tow conveyor
14.Trolley conveyor
15.Power-and-free conveyor
18.Monorail
19.Station conveyor
a) Diverter d) Tilting device
b) Pop-up device e) Cross-belt transfer device
c) Sliding shoe device

7. Belt Conveyors Characteristics Very Efficient
Damage to the products is very low
High Carrying capacity
Long distance conveying
Long service life

8. Elements of a belt conveyor
Feeder
Belt
Idler Pulley
Pulley
Discharge
Drive

10. 1) Belt -consists of one or more layers of material
1) Belt -consists of one or more layers of material. Many belts -two layers. An under layer (carcass) for linear strength and shape an over layer (cover). The carcass is often a woven fabric -polyester, nylon and cotton. The cover is often various rubber or plastic compounds specified by use of the belt. 
2) Drive
- Drive the mechanism
-Located at the end of the discharge to
prevent the sag

11. 3. Pulley
- Large enough to provide enough contact
surface with the belt to ensure a positive
drive
4. The Take Up
- Automatic or manual adjustment for contraction or expansion of the belt due to moisture and temperature.

12. 5. Idler Pulleys
- Material – Plain wood or light steel
- Multiples to increase carrying capacity
6. Feeder
- Free flow – Single funnel with a gate valve
- Not a free flow - Screw feeder, vibrating
feeder , Star feeder

13. 7) Discharge
- Placed at the end of the belt
- Types
a) Tripper
b) Angle Scrapper

14. Types of belt conveyors
Flat belt conveyor

15. Transport Medium and light weight loads
Inclined or decline when it is required
Provide considerable control over the orientation and placement of the load
No smooth accumulation, merging and sorting on the belt
The belt is roller or slider bed supported

16. Magnetic belt conveyor
For transporting ferrous materials

17. Trough belt conveyor

18. Designing Belt Capacity Determination BLTCAP = 0.8 * CSA * BLTS
BLTCAP – Conveyor belt capacity (bu/min)
SI units can be used m3, m2 & ms-1
Belt capacity vary according to the belt width and surcharge angle
CSA – Cross sectional area (ft2)
BLTS – Belt speed (ft/min)
(1bushel = cubic feet)

19. Horse Power Requirement Determination
1. Horse power to drive = BLTS * (A+BL)/100
empty conveyor
BLTS – Belt speed (ft/min)
L - Conveyor length in feet
A, B – Constants depend on belt width
2.Horse power to
convey material = tons of material * ( L)/100
on level per hour
(Metric tonne = 1000kg ton = 2240 pounds or 1016kg)
1 t = t

20. 1hp =745.7 W 3. Horse power to = Lift * 1.015 * tons of
lift the material in ft material per h/1000
Simplified SI calculation
Power (kW) = (Capacity (t/h)* lift (m)* 3.75)/1000
**** True for <10% slope
**** If efficiency of drive mechanism is < 95% use instead 3.75
1hp =745.7 W

21. SI detailed calculation

22. The basics of the Calculations of Conveyor Belt Design Parameters
Belt tension: The belt of the conveyor always experience a tensile load due to the rotation of the electric drive, weight of the conveyed materials, and due to the idlers. The belt tension at steady state can be calculated as:
Tb = 1.37*f*L*g*[2*mi+ (2*mb + mm)*cos (δ)] + (H*g*mm)…….eqn.1.1

23. Where,
Tb is in Newton.
f = Coefficient of friction
L = Conveyor length in meters. Conveyor length is approximately half of the total belt length.
g = Acceleration due to gravity = 9.81 m/sec2
mi = Load due to the idlers in kg/m.
mb = Load due to belt in kg/m.
mm = Load due to the conveyed materials in kg/m.
δ = Inclination angle of the conveyor in Degree.
H = vertical height of the conveyor in meters.

24. Load due to idlers (mi): This can be calculated as below:
mi = (mass of a set of idlers) / (idlers spacing) ……………..eqn.1.2
Power at drive pulley: The power required at the drive pulley can be calculated from the belt tension value as below:
Pp = (Tb*v)/1000……………..eqn.1.3
Where,
Pp is in kW.
Tb = steady state belt tension in N.
v = belt speed in m/sec.

25. Tb = the steady state belt tension in N. Ks = the start-up factor
Belt tension while starting the system: Initially during the start of the conveyor system, the tension in the belt will be much higher than the tension in steady state. The belt tension while starting can be calculated as:
Tbs =Tb*Ks………………..eqn.1.4
Where,
Tbs is in N.
Tb = the steady state belt tension in N.
Ks = the start-up factor

26. Pp = the power at drive pulley in kw Kd = Drive efficiency.
Sizing of the motor: 
The minimum motor power can be calculated as:
Pm = Pp/Kd………………eqn.1.5
Where,
Pm is in kw.
Pp = the power at drive pulley in kw
Kd = Drive efficiency.

27. Acceleration : 
The acceleration of the conveyor belt can be calculated as:
A= (Tbs – Tb)/ [L*(2*mi + 2*mb+mm)]………eqn.1.6
Where,
A is in m/sec2
Tbs = the belt tension while starting in N.
Tb = the belt tension in steady state in N.
L = the length of the conveyor in meters.
mi = Load due to the idlers in kg/m.
mb = Load due to belt in kg/m.
mm = Load due to the conveyed materials in kg/m.

28. An Example of Conveyor Belt Calculations
Input data:
Conveyor capacity (Cc) = 1500 t/h = kg/sec
Belt speed (V) = 1.5 m/sec
Conveyor height (H) = 20 m
Conveyor length (L) = 250 m
Mass of a set of idlers (m’i) = 20 kg
Idler spacing (l’) = 1.2 m
Load due to belt (mb) = 25 kg/m
Inclination angle of the conveyor (δ) = 5 0
Coefficient of friction (f) = 0.02

29. Drive efficiency (Kd) = 0.9 Friction factor (Cr) = 15
Start-up factor (Ks) = 1.5
Drive efficiency (Kd) = 0.9
Friction factor (Cr) = 15
Breaking strength loss factor (Cv) = 0.75
First, we will use the eqn.1.2 for finding out the load due to idlers:
mi = (20/1.2) = 16.67 kg/m
We will use the eqn.1.1 for finding out the belt tension in steady state:

30. Tb = 1.37*0.02*250*9.81*[ {2*25+ (416.67/1.5)}*cos (5)] + (20*9.81* (416.67/1.5)) =  N.
The belt tension while starting the system can be calculated by using the eqn.1.4:
Tbs = 1.5 * =  N
For calculating the power at drive pulley, we will use the eqn.1.3:
Pp = ( *1.5)/ 1000 =  kw
We will use the eqn.1.5 estimate the size of the motor:
Pm = /0.9 =  kw

31. A = (116335.32 - 77556.88)/ [250*{(2*16.67) + (2*25) + (416.67/1.5)}]
We will use the eqn.1.6 to find out the acceleration of the motor:
A = ( )/ [250*{(2*16.67) + (2*25) + (416.67/1.5)}]
= 0.429 m/sec2

32. Chain Conveyors

33. Having a powered continuous chain arrangement
If the chain at bottom is called the drag
The chain at the top is called as the flight
Operate at less than 200ft/min (Slow process)
Noise is a problem

34. Trolley conveyor
Overhead trolleys fastened by a chain
Can have 1800 turn and steep elevations
Commonly used in processing, assembly, packaging, and storage operations

35. Scraper conveyor
A type of flight conveyor. It consists of a trough in which a continuous driven chain with flights is running. The flights are scraping the material over the bottom of the casing. The material is moving forward to the discharge point
Used for granular
or non abrasive materials
Power requirement is
high
Use for many raw
products

36. Apron conveyor
Flights in scraper conveyors are replaced with the flat slats, steel plates or boards
Have a moving platform or apron to convey sacked materials and large units
The apron conveyor is an economical design for horizontal and inclined conveying up to 28°. Special features may be added to make inclinations of up to 60° possible. An extremely low-cost unit preferred for applications of up to 45° inclination.

38. Chain conveyor design Generally flight speed – 75 -125ft/min
Capacity decreases with inclination
Horse power requirement
Horse power = 2* V *Lc* Wc* Fc + Q(L *Fm +H)
33000
V – Speed of the conveyor
Lc - Horizontal projection length of conveyor (ft)
Lc = cos ( c) * TCL
[ =cos(angle of elevation conveyor) * Total conveyor length]

39. Wc – Weight of flight and chain (lb/ft)
Total conveyor length
Conveyor length after loading
Wc – Weight of flight and chain (lb/ft)
Fc – Coefficient of friction for chain and
flight
Q – Material to be handled (lb/min)
L - Horizontal projected length of loaded
conveyor (ft)
L = cos (c ) TLL =cos(angle of elevation conveyor) * Total Loaded length of conveyor

40. Fm – Coefficient of friction for material H – Height of lift (ft)
H = Sin (angle of elevation conveyor) * Total length of conveyor

41. Bucket Elevators

42. A special adaptation of both belt and chain conveyors
Very efficient in moving things vertically
It consists of:
Buckets to contain the material
A belt or chains to carry the buckets and transmit the pull
Means to drive the belt
Accessories
for loading the buckets or picking up the material
for receiving the discharged material
for maintaining the belt tension
for enclosing and protecting the elevator.

43. Components of a Bucket Elevator
Head pulley
Head drive
Components of a Bucket Elevator
motor
Garner Throat
Head drive
(Reducer)
Leg Belts
Leg
Elevator Buckets
Deflector pulley
Take -ups
Boot pulley
Boot spout
Boot

46. Discharging mechanisms
Centrifugal action
Gravity action

47. Types of buckets

48. Applications
A bucket elevator can elevate a variety of bulk materials from light to heavy and from fine to large lumps
Eg:
Food products – grain, sugar, flour, coffee, salt..
Rock products – sand, gravel, cement, gypsum, limestone
Chemical processing products – fertilizer, phosphate, agricultural lime , soda ash
Pulp and paper products

49. Designing Power requirement determination
Horse Power Requirement = Q.H / 33,000
Q = material handled (lb/min)
= Belt speed * No of buckets per foot * Bucket capacity
H = Lift (Ft)

50. - Theoretical value is increased by 10 to 15 % for,
friction
power for loading
- Also additional power is needed for,
starting under load
peak load

51. Advantages Low power requirement Long service life
Minimum maintenance requirement
Ability to handle wet grains as easy as dry grains with negligible increase of power
Relative quietness
But Grain damage may be high in handling seed purpose grains!!!!

52. The Screw conveyor

54. The capacity of a screw conveyor depends on the screw diameter, screw pitch, speed of the screw and the loading efficiency of the cross sectional area of the screw.
The capacity of a screw conveyor with a continuous screw:
Q = V. ρ
Q = 60. (π/4).D2.S.n.ψ.ρ.C
Where,
Q = capacity of a screw conveyor

55. V = Volumetric capacity in m3/h
ρ = Bulk density of the material, kg/m3
D = Nominal diameter of Screw in m
S = Screw pitch in m
N = RPM of screw
Ψ = Loading efficiency of the screw
C = Factor to take into account the inclination of the conveyor
Screw Pitch:
Commonly the screw pitch is taken equal to the diameter of the screw D. However it may range 0.75 – 1.0 times the diameter of the screw.

56. RPM of Screw:
The usual range of RPM of screw is 10 to 165. It depends on the diameter of screw and the type of material (Max RPM of screw conveyor is 165)
Loading efficiency:
The value is large for free flowing and non abrasive,
Ψ = 0.12 to 0.15 for abrasive material
= 0.25 to 0.3 for mildly abrasive material
= 0.4 to 0.45 for non abrasive free flowing materials

57. The inclination factor C is determined by
the angle of screw conveyor with the horizontal.

58. Oscillating conveyors

59. Metallic trough carried on inclined arms fitted with rubber bushes to handle the reciprocating motion of the trough
The oscillating motion of the trough is achieved via specially designed inclined arms and an eccentric shaft driven by a motor through v – belts

60. PRINCIPLE CONVEYOR TROUGH IMPARTS VELOCITIES IN x & y DIRECTIONS

61. F1 F2 F4 F3
Figure 2
Figure 1
FORCES ON ‘ Y ‘ DIRECTION
F1 - ACCELARATION FORCE
F2 - PARTICLE WEIGHT
FORCES ON ‘ X ‘ DIRECTION
F3 - FORCE IN THE X DIRECTION
F4 - FRICTION

62. F1>F2
PARTICLE LIFTS &
MOVES AXIALLY BY A SHORT TRAJECTORY
F3>F4
PARTICLE MOVES MAXIMUM X DISTANCE DURING FLIGHT

63. DESIGN CRITERIA

64. END PART_1

65. Belt conveyor design following site for SI