Conveyor systems

01

Match the conveyor type to the load

Plant Engineering's guide to powered belt and roller conveyors for unit handling (items with a definable shape such as packages, cartons and totes) says belt conveyors suit loads whose speed and spacing must be controlled, can run horizontally or incline and decline, and are fixed, portable or telescoping, operating at 40–60 fpm in the guide's figures with up to 200 fpm available and a maximum live load of about 150 lb/ft on belt widths of 12–36 in. Slider-bed belts run on a continuous surface with a 25–30% friction coefficient, needing larger motors, and suit small, unstable, light-to-medium irregular items, elevation changes and constant spacing; roller-bed belts run on rollers with about 5% friction, lasting longer at lower operating cost, with two or three rollers under every product. [1]

The guide says roller conveyors are the better choice for accumulation, because zero- and minimum-pressure options can slot or halt product, and for systems with merges, curves and diversions. Belt-driven (flat or V-belt) roller conveyors serve light-to-medium cartons and totes, V-belts flexing around curves; line-shaft conveyors drive each roller through polyurethane belts from one shaft, for light-to-medium transporting, sorting and accumulating; chain-driven roller conveyors serve medium-to-heavy loads, continuous chain for transport but not frequent starts and stops, and roller-to-roller chain for pallets, skids or drums up to 10,000 lb with starting, stopping and reversing. It lists selection factors as load dimensions and weight, throughput, safety, flexibility and expandability, economics, noise and automation level. [1]

Editorial calculation: for the same 1,000 lb of load on the belt, the guide's friction coefficients give a drag of about 250–300 lb on a slider bed against about 50 lb on a roller bed — five to six times less — which is why roller-bed belts need smaller motors and drives. [1]

Editorial note: bulk materials, PCBs, pallets, chips and pneumatic transport have their own CNFX pages; use this page to decide the family, then specify on the specific page.

Give the supplier the items or material conveyed (dimensions, weight, base shape, temperature, fragility), throughput per hour, layout drawing with elevations, curves, merges and diverts, accumulation needs, speed, environment (washdown, dust, temperature), controls and integration (PLC, WMS/MES), noise limits, safety requirements, power supply, and installation scope.

02

Plan controls, guarding and safety

OSHA 29 CFR 1926.555 (conveyors in construction) requires a means to stop the motor at the operator's station, and at the motor if the station is remote; an audible warning immediately before start-up; emergency stop switches that must be reset before the conveyor can restart; guarding of screw conveyor flights; guards where conveyors pass over work areas, aisles or passageways, with crossings marked; lockout and 'Do Not Operate' tagging during repairs; and conformity with ANSI B20.1 for design, construction, inspection, testing, maintenance and operation. [2]

Plant Engineering's safety sidebar adds on-off controls near workstations with more than one pushbutton station on long runs, an emergency pull cord along the conveyor, warning lights and buzzers before start-up, guards on drives, nip points between belts and pulleys, couplings and sprockets and under overhead conveyors, and noise control by lower speeds, less metal-to-metal contact, tight fasteners and quality bearings. [1]

Editorial note: OSHA 1926.555 applies to construction work; general-industry plants follow their own machine-guarding rules and ASME B20.1, so state the safety standard you require in the enquiry.

03

Compare conveyor system suppliers

These companies list conveyors for different industries; check that each one's range matches your load and layout.

04

Map the guarding rules that apply outside construction

Minnesota OSHA's instruction on guarding belt conveyors sets out which federal rules an inspector cites for conveyors outside construction and pulp and paper mills. Drive components (belts and pulleys, chains and sprockets) fall under 1910.219, which excludes the driving pulley on which the conveyor belt runs; in-going nip points, shear points and rotating parts fall under 1910.212(a)(1), and guarding by location is allowed at 8' or more above the floor. Where staff remove or bypass a guard for servicing, a lockout/tagout program under 1910.147 must be in place. Conveyors above exit passageways, aisles or corridors should leave a clearance of at least 6' 8". [3]

For pulp, paper and paperboard mills, the instruction cites 1910.261(c)(15): an emergency stop cable along the length of the conveyor, or stop buttons within 10 feet of each work station. It also notes that ANSI B20.1 2015 allows lubrication during operation only if shutdown is impractical and only by trained, qualified personnel. Where B20.1 'shall' provisions are not met, Minnesota can cite its general duty clause, for example for remotely or automatically controlled conveyors without emergency stop devices, or missing spill or pan guards. [3]

Editorial calculation: 8' is about 2.44 m and 6' 8" about 2.03 m (1 ft = 0.3048 m); give these heights to the supplier when routing conveyors over walkways. [3]

05

Size motorised-roller zones from the load and gear-ratio tables

Interroll's datasheet for its RollerDrive EC5000, a 60 mm motorised conveyor roller with the motor integrated in the tube, describes it as a drive for unit-handling conveyors carrying cartons, containers, tyres or lightweight pallets, suited to straight conveyors and especially to zero-pressure accumulation conveyors. The 50 W roller runs on 24 V or 48 V, with rated current of 3.4 A or 1.7 A and starting current of 7.5 A or 3.8 A, in ambient temperatures of 0 to 40 °C, and lists maximum installed noise of 55 dB(A), application-dependent. [4]

Load is rated per zone and per roller. A zone driven by the RollerDrive carries up to 2500 N with a polyamide drive head or 5000 N with a welded steel drive head; a single RollerDrive carries 1100 N without a drive head, 550 N with a polyamide PolyVee head and 1100 N with a welded steel PolyVee or double-sprocket head. These values assume two-dimensional loading of the tube; for one-dimensional loads such as pallets the load per roller is reduced, and not all rollers support the pallet. [4]

The gear ratio sets speed and torque, as the table shows; Interroll states that values may differ by up to ±20 % before run-in and stay within ±10 % for 95 % of rollers after it. [4] Editorial calculation: 0.52 m/s at 42:1 is about 102 fpm (0.52 × 196.85), above the 40–60 fpm belt speeds in Plant Engineering's guide, and 5000 N is about 1,124 lbf (5000 ÷ 4.448). Give the supplier your heaviest unit load, its footprint, zone length and required speed so it can choose the drive head and gear ratio. [1]

06

Trace the system components

This is a functional reference built from the sources cited; it is not one maker's design.

07

Fill the specification fields with values for your plant

A conveyor system quotation needs values for your loads and layout. The table explains each field, gives published values where a reviewed source states them, and says what to obtain from the supplier.

08

Send the load, layout and safety data together

Paste it into your enquiry below or into an email to a maker, then replace every bracket.

Load: [items or material; size; weight; per hour]
Layout: [length; elevations; curves; merges; diverts]
Function: [transport; accumulate; sort]
Environment: [washdown; dust; temperature]
Controls: [PLC; stations; integration]
Safety: [standard; guards; stops]
Supply: [installation; spares; training]

See manufacturer records Send an enquiry through CNFX