Rollers / Stations
|Product range "NM"|
|Product range "NS"|
|View construction drawing "NM"|
|View construction drawing "NS"|
|Industries - application|
Item#06Return rollers with helical rubber rings for self cleaning - arrangement "NM"
Used on the return transom to support the belt when the material being conveyed, even if only a little sticky, is very viscous. The helical spiral form of the non-abrasive rings, assembled onto the base roller shell, performs a cleaning action and reduces the tendency of material to deposit itself and stick to the surface of the dirty side of the belt.
They may be employed on any part of the return belt section in the case of short conveyors. On long sections it is satisfactory to employ these rollers only up to the point where the material does not adhere any more to the belt surface. These rollers should not be employed as snub rollers adjacent to the drive or return drums.
Return rollers with helical steel cage for self cleaning - arrangement "NS"
Used in the return section to support the belt when the conveyed material is very adhesive, as with for example clay.
They may be positioned on any part of the conveyor return section, when it is relatively short. When these rollers are produced with a spiral steel cage, it is attached to the two end caps with similar characteristics to the PSV rollers series.
The spiral cage, in permanent contact with the dirty side of the belt, removes material from the belt using its natural rotary cleaning action.
The rollers should be installed in a way that the spiral moves the material towards the edge of the belt. These rollers must not be employed as belt snub rollers.
The tables indicate the standard types and diameters with their dimensions according to European norms. On customer request cleaning rollers may be supplied with spirals in steel, with non standard dimensions and characteristics (for example steel spiral in flattened format).
Click to download NM product range
Click to download NS product range
Download “BULK ROLLER SELECTION FORM”
SELF-CLEANING - Roller selection
If you have already decided
• roller dimensions as A, B, C lengths
• shell and shaft diameter
• bearings size
• eventual rubber rings or special coatings
• and the load capacity
the roller selection can be done by simply looking into our catalogue pages and finding the correct roller to suit the requested data.
In the case that only the conveyor data is known, but the roller size is not decided, the roller selection type (series, steel, plastic, coated) and dimensions (shell and shaft diameter, bearing size, eventual rubber rings) depends on the following application data. This data must be given by the conveyor designer (for new projects) or by the end user or maintenance contractor (for spare parts):
• Belt width [mm]
• Conveyor capacity [t/h)]
• Belt Speed [m/s]
• Belt weight per meter [kg/m]
• Roller diameter (if stated) [mm]
• Idler sets distance (stations pitch) [mm]
• Angle of the side rollers (20°, 30°, 35°, 45° or other)
• N° theoretical bearing lifetime hours L10h requested (10.000, 30.000, 50.000 or other)
• Material lump size (max material block dimension) [mm]
• Transported material type, condition (dry, wet, sticky), abrasion, corrosion
• Climate, max & min temperature, marine or chemical corrosive environment.
For return rollers selection in addition to the above data :
- Are they a single flat return roller or V-return rollers?
- Are rubber rings required on the tube?
- What would be the: base roller diameter/rubber ring diameter (if stated)
- Their configuration (NG, NL, NC etc. see catalogue pages).
For impact rollers calculation selection:
- Drop height of material [mm]
- Max material lump size[mm]
- Type of loading (free fall on the belt, hopper, loading inclined plane, extractor conveyor).
According to this data and a proper load capacity and lifetime calculation (see our technical chapter), the rollers can be selected and dimensioned.
For help and guidelines with regard to roller loading capacity we refer to our roller catalogue (direct download our catalogue from this web site or request it from your local Rulmeca offices.)
In case you are not familiar with this selection and calculations, please fill accurately the attached "Bulk roller selection form" with all the requested data and send it to your local Rulmeca office.
Download “BULK ROLLER SELECTION FORM”