Idlers
The idlers are standardised and designed according to DIN 22107, and on request according to CEMA 502-2001 (B, C, D, E), SABS, BS. TRANZA is capable of delivering unique idlers made from fibreglass composites which combine high strength with low specific weight and excellent anticorrosion and antistatic properties.
TRANZA also offers a range of special-design idlers: idlers for extreme climate conditions, for extremely heavy-duty applications, specific load distributions and zero gap idlers.
TRANZA provide two styles of idler base frame design:
Section base frames
are used for belt widths of 400 mm - 1400 mm. They are adapted for assembly on conveyor structures made from "U" sections. The idlers are mounted on the conveyor structure using support brackets without drilling holes in the conveyor structure. The idlers are welded from flat and angled steel sections. Return rollers brackets are also mounted without drilling holes.
Tube base frames
are used for belt widths of 1000 mm - 2000 mm. They are sunk between the sections of the support structure to reduce tilting moments. They are welded together using cambered tubes and flat steel. Nuts and bolts are used for attaching the idlers to the conveyor structure (these should be ordered separately). The tube base frame is particularly suitable for extremely heavy-duty conditions.
All idlers have quality rollers from our production.
Carrying sets
The first group of idlers covers carrying sets which support the loaded section of the belt and move the material. They are located in the upper part of the conveyor.
Return sets
Return sets are located in the bottom part of the conveyor and support the belt on its return from the discharge point to the tail pulley. The designs of return sets are essentially the same as for carrying sets.
Impact sets
Their function is to ensure maximum belt protection for the optimum service life. Impact idlers are positioned at the loading points where bulk material falling onto the belt could cause damage to it. Impact sets are equipped with rubber-lagged rollers or impact rollers with a number of rubber rings of appropriate thickness and resistance.
Carrying or return belt training sets
Troughing or flat idlers assist in keeping the conveyor belt centred on the conveyor when temporary or transient conditions could result in belt misalignment. Two small side rollers attached vertically to the base frame provide for self-alignment of the belt. Training sets are generally spaced 30 m apart and not within 15 m of the head or tail pulley. The effectiveness of trainer sets is enhanced by the use of urethane rollers.
Centring idlers
These idlers are used for supporting the carrying belt. They have a centring effect caused by a slight incline of the axes of the side rollers (approx. 2°). They have the same function as training idlers but they are used on smaller dimension belts (for belt lengths up to 100 m). If they are used they should be fitted along the whole length of the conveyor.
Self-cleaning sets
Several types are available: "Vee", flat, brackets and garland sets. Disc and spiral rollers are used. Disc rollers are used where sticky materials adhere to the belt, in a corrosive environment or where abrasive wear is a problem. These idlers can be used for belt travel in either direction.
Compacted end discs are standard. Spiral rollers are used under the same conditions as disc rollers. Their unique construction minimises belt fleet and damage to the return belt due to material build-up on the idler rollers. Spiral roller idlers can only be used for belt travel in one direction.