2026-10-09
Working conditions: a fertiliser granulation line
This is a typical working condition rather than a single named plant: a fertiliser granulation line. The screening step is finished-product screening, and after it the material is moved by belt conveyor and by bucket elevator.
The material on the line is corrosive and takes up moisture easily. Both properties have to be allowed for when the parts for the line are specified.
Screen media: three materials, selected by the material
Screen media is selected by the material being screened. Three materials are used on fertiliser lines, and each one trades price, service life and noise differently.
- Manganese steel screen: good toughness and impact resistance.
- Polyurethane screen: service life is about twice that of ordinary manganese steel, at a slightly higher price. It suits wet, sticky material.
- Rubber screen: low noise and impact resistance.
Each of the three answers a different condition on the line: impact, wet and sticky material, or noise. Service life is what sets the interval between screen changes, so it is the figure to weigh against the price difference on a wet, sticky duty.
Corrosion, sticking material and the standard configuration
A fertiliser line is sensitive to corrosion and to material sticking. Rubber-lagged rollers and polyurethane screens are the standard configuration on this duty.
The bucket elevator is fitted by the same rule: the chain and sprocket, the conveyor belt and the iron remover are all selected to suit the material. Each item is chosen against the material it will handle, not from one standard list.
Supporting parts for the vibrating screen: coupling, drive shaft assembly, oil lubrication station assembly, high-strength bolts, starter cabinet.
Maintenance: screen replacement and chain tension
A screen that has developed a hole lets coarse material through, and coarse material reaching the finished product directly affects the qualified-product rate. The screen is therefore a quality item, not only a wear item.
Set the replacement point by tonnage passed, not by the calendar. Tonnage tracks what the screen has actually carried; the calendar does not.
Check bucket elevator chain tension at regular intervals. Tension checks protect the sprocket as well as the chain: if the chain jumps teeth, the sprocket is scrapped with it.
Set the replacement point by tonnage passed, not by the calendar.