Most modern screens are designed with the benefit of modern CAD & computer simulation techniques and can cope with a wide range of operational conditions under very different applications.
However, variations in feed rates and composition of the material being processed can, in some circumstances, result in an excessive amount of material being on the screen at any one time. If, as a result, the rate and speed of vibration of the screen slows down, even temporarily, problems can quickly occur, causing blockages, stoppages, downtime etc, inevitably leading to a major situation & proving to be very costly to rectify.
Material continues to be fed on to the screen at the normal rate but the slowdown causes the discharge rate to be reduced, a marginal overload can quickly enter a runaway situation with material arriving at the screen causing an ever increasing overload and further slowdown. Mechanical failure, V-belt ‘burn off’ or the intervention of the drive motors electrical overload is often the first time the operator will know that all is not well.
Rotech’s Vibration sensor VS4000 fitted to a screen is designed to monitor its rate of vibration and will operate an alarm or switch the in-feed conveyor off if the screen slows down. Even a drop in speed of 5% for a few milliseconds can be detached and action taken almost instantaneously. On V-belt-driven screens the drive motor can be switched off the moment any slippage occurs, preventing extensive damage to the belts.
The VS4000 signal output can be connected to the Plant PLC/Computer or independently used with the Rotech Vibration Relay – SR4000 series.
Typically on a screen vibrating at 750 throws per minute, the SR4000 Vibration Relay is set at 725 TPM, if the speed drops below this level, the relay operates in less than 10 milliseconds.
For more information, click on the links below to browse the Rotech Systems website where you can download data sheets & application information.
Tel: +44 (0) 151 356 2322
Fax: +44 (0) 151 356 2437
Website: www.rotechsystens.com/products
Applications Data: www.rotechsystems.com/vibrationsensorapplications
Email Rotechs Systems:info@rotechsystems.co.uk
