| Belt width | Measure the belt’s nominal width, not the conveyor frame width. Confirm the value from the conveyor drawing or by measuring the belt. | Common bulk-conveyor widths include 500, 650, 800, 1,000, 1,200 and 1,400 mm. | Helps establish the required roller face length and idler-frame configuration. The correct face length also depends on trough geometry and clearances. |
| Roller face length and frame dimensions | Record the existing roller’s usable face length, overall length, shaft-end dimensions, and the distance between frame mounting points. Note whether the conveyor uses a troughing or flat idler. | Use the measured assembly dimensions; do not infer roller length from belt width alone. | A roller that is too short, too long, or has incompatible shaft ends may not fit or support the belt correctly. |
| Trough angle and idler arrangement | Measure the wing-roll angle or verify it on the equipment drawing. Record the number of rolls per set and the center-roll and wing-roll lengths. | Common trough angles include 20°, 35° and 45°; the installed angle must match the conveyor design. | Trough geometry affects belt support, roller lengths, belt tracking, and how material load is distributed across the idler set. |
| Roller outside diameter | Measure the roller shell diameter, excluding any coating or buildup. Confirm the bearing and shaft arrangement when replacing an existing roller. | Bulk-conveyor roller diameters commonly fall within approximately 76–159 mm, depending on the design and duty. | Diameter influences rotational speed, bearing selection, shell stiffness, and suitability for the conveyor’s load and operating speed. |
| Belt speed and throughput | Record the operating belt speed in m/s and the maximum design throughput in t/h. Use the maximum expected operating duty, not only the average. | Example: 600 t/h at 2.0 m/s corresponds to about 83.3 kg of conveyed material per metre of belt, before adding belt mass. | Throughput and speed help establish material load per unit length. Higher speed also increases roller rotational speed and may affect bearing and sealing requirements. |
| Material bulk density and lump size | Record the material’s bulk density, maximum lump size, moisture, abrasiveness, and whether the feed drops onto the belt. | Bulk density is specified in kg/m³ or t/m³. For example, a material with 150 mm maximum lumps may require a different loading-zone arrangement than fine material. | Density affects conveyed mass; large or heavy lumps and impact at the loading point can increase local roller loads and wear. |
| Idler spacing and roller-set load | Measure the distance between carrying idler sets and return idlers. Note whether spacing changes near the loading zone, pulleys, or transition areas. | Preliminary layouts often use about 0.8–1.5 m between carrying idlers and 2–3 m between return idlers; actual spacing is design-dependent. | Closer spacing generally reduces the load carried by each set. Final roller loads must account for belt mass, material mass, load distribution, and dynamic effects. |
| Belt mass, tension, and operating conditions | Obtain belt mass per metre, relevant belt-tension data, start/stop frequency, operating hours, ambient temperature, and exposure to water, dust, or chemicals. | Provide values from the belt and conveyor specifications; they vary with belt construction and installation. | These conditions inform the required roller, shaft, bearing, and seal duty. Confirm capacity against the conveyor design rather than relying on a generic load figure. |
| Loading-zone impact and duty cycle | Identify the loading point, drop height, impact frequency, and whether the conveyor runs continuously or intermittently. | Record the actual drop height and operating schedule; these are installation-specific. | Impact zones may need purpose-designed impact support. A standard carrying roller should not be assumed suitable for every loading condition. |