Chrome Plated Rollers

ABSTRACT

This paper presents an experimental investigation on applying different types of rollers in order to obtain optimized roller life time and screening performance. Roller screen classifies green pellets coming from balling disc; which usually includes three sections for sorting pellets in three grain sizes: undersize section (0-9 mm), product section (9-16 mm) and oversize section (+16 mm). Some transfer rollers are also placed between each two sections. Using stainless steel 304 rollers results in uniform material flow with lower manufacturing cost. However, the main problem occurs due to non-uniform wear of rollers that results in non-uniform opening gap. This phenomenon reduces both process efficiency and producing capacity about 3 to 5%. Moreover, the time required to stop the equipment for re-gapping the worn rollers is another disadvantage of stainless steel rollers. Thus, by application of chrome plating, enhancement of rollers life time as well as skipping gap re-adjustment can be expected. Accordingly, the experimental setup is designed and verification tests are performed in Ardakan pelletizing plants of Iran. Subsequently, it is shown that chrome plated rollers are performing properly for beginning of undersize section and transferring section, while using such rollers in product section dramatically reduces classifying efficiency. Finally, proper configuration for using different rollers on a roller screen is suggested.