Operation of Vibrating Screen
Clear away dust and stones from the base of the springs daily.
Listen and notice the abnormal sound. If screen is not running normally (uneven strokes, broken springs, loose/missing bolts, cracked screen body, broken media, material built-up in vibrating equipment & hitting to structures, loss of V-belts tension, noisy bearings, bearing temperature too high, etc.), stop it immediately and report it to service people.
If possible, always empty the screen before stopping it. Empty screen starts easier. Do not load screen too heavily. It leads to a carryover problem and less screening efficiency.
If the vibrating frame is bottomed out on the springs due to the weight of backed up material, (unusually due to heavy feed surge, plugged chutes, etc.) shut down the screen immediately. The back-up should be cleared by hand. Attempting to clear the back-up by running the unit will lead to spring and frame breakage. Worn paint or bare metal between coils is hard evidence that the spring has been totally collapsed.
Weekly Checks
- Oil level/s
- Condition of screening media (Check damage / wear of media cloth / module plates)
- Check apertures blockage due to plugging and blinding
- Condition of wear parts (liners)
- Condition of springs (Check physical condition / damage due to wear, corrosion, cracks etc. Clear away dust and large particles / stones from the base of the springs so that springs are free to compress & expand freely)
- Bolts joints (Visual inspection for tightness)
- Stroke lengths and angles
Bearings
lt is advisable to change the bearings if one or more of the following symptoms appear in the screen.
- The bearings overheat
- There is unusual noise in the bearing during operation
- The bearing has many operation hours or the clearance between the outer ring and the rollers is too significant
Rolling bearings in vibrating screens are stressed by high, mostly shock-type loads. Moreover, the bearings, while rotating about their own axis, perform a circular, elliptical or linear vibrating motion. This results in high radial accelerations which additionally stress the bearings, and especially the cages, considerably. In view of this, always use bearings recommended by screen manufacturer (standard bearings with C4 clearance may not be suitable!). Compared with grease lubrication, oil-bath lubricated bearings run cooler, require less attention. Last longer and adapt better to temperature extremes.