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7. Cost Performance of Belt Conveyor

The electric power for belt conveyor drive is a very important point to plant operators and designers. Plant designers have to consider the size of belt frame, the arrangement and diameter of belt pulley, the size of bearing and shaft depend fully on the electric power (motor size). Proper design and choice of components can greatly reduce the operation cost. The formula for B/C drive power is specified on KS B6406 and JIS B8805 D “Method of calculation and tests for rubber belt conveyor”. You can see on this report how the weight of rollers effect the belt conveyor drive power and how much money can be saved through using the ULTROL^® of POLTEC Corporation.

P = P1 + P2 + P3

= 0.06 × f × W× v × (l + lo) + f × Qt × (l + lo) ±(H×Qt)

367 367 367

P : Total Electric Power (Kw)

P1 : Electric Power without load

P2 : Electric Power by horizontal load

P3 : Electric Power by vertical load

f : Coefficient of friction of roller

W : Electric Power for moving parts without load

v : Velocity of B/C(m/min.)

l : Length of B/C

lo : Center length of B/C (m)

Q : Material Flow (ton/h)

H : Height of B/C from the bottom to the top (m)

H, v, l, Q, H are variable depending on the design of B/C system. Among these factors, W (electric power for moving parts) depends mainly on the weight of roller. Therefore, the weight of roller finally gives the electric power for B/C operation a great effect. You can see the effect of W more detail.

W = Wc + Wr + 2Wb

2.4

Wc : Weight of 1 set of Carrier Roller

Wr : Weight of Return Roller

Wb : Weight of B/C (Kg/m)

You can realize that W depends on the material of rollers and the weight of B/C. If the same conveyor belts are selected, W is solely dependent upon the weight of rollers. Table 3-4 on KS B presents W according to the belt width.

W : KS B 6406

Belt width (mm)	900	1050	1200	1400	1600
Steel Roller	63	80	90	112	125
ULTROL	40	64	72	88	98

Assuming :

F = 0.03 V = 140 M/min Lo = 49

L = 700M Q = 120 Ton/Hr H = 30 M

Steel Roller

P = 0.06×0.03×112×140×	(700 + 49)	+ 0.03×120×	(700 + 49)	+ (120×30)
	367		367	367
= 74.76(Kw)

ULTROL

P = 0.06×0.03×88×140×	(700 + 49)	+ 0.03×120×	(700 + 49)	+ (120×30)
	367		367	367
= 62.41(Kw)

In conclusion, We could verify that less roller weighs, the less electric power requires for B/C drive. About 16% of electric power are saved by the change of the material of roller. Also, don’t forget ULTROL^® is more durable, calm, clean than Steel Roller is