the type of conveyor belt studied in this research was cotton/rayon staple. steady-state design theory was applied to analyze conveyor tension, the number ply and the size of driver set. Figure 1 shows the calculation process to design the conveyor. The calculation started from inputting convey capacity , conveyor length, properties of conveyed material, conveyor's inclination angle,angle of support wheel, detail of instollation and properties of belt. After that, there wa the calcullation on each belt width to find out the number of ply, the conveyor driver power and number of support wheel. The result from the calculation to each belt width was appliedto analyze the total cost.
2.2 calculation of the coveyor cost
The conveyor cost was calculation from the price and expenses of conveyor components which were designed from Fig. 1. Theconveyor cost in this study waas divided into 6 groups:
-The cost of belt support and components that are carrier roller, return braacket and belt cleaners
-Driver costs that are head and tail pulley, motor, gear box, drive and driven pulley, pulley belt, pulley shaft, bearing, driver housing and control system
-Conveyor frame cost
-Conveyor belt cost
-Energr cost
-Installation cost
Lifetime of the conveyor was determined from the component of which lifetime was longest, which was conveyor frame. The number of conveyor's components that there used for the whole lifetime of conveyor was determined by the quotient of the conveyor's lifetime and the lifetime of its components. The lifetime of each component is show in Table 1.