CONVEYOR BELT MONITORING

There will always be incidents that cause conveyor belt failures. Unplanned conveyor downtimes are often a catastrophic and very costly result, that must be avoided. Hence, good belt scanning is highly advisable, well, even a must.

Below are short descriptions of the main types of monitoring.

VISUAL INSPECTION

Used for
Belt damages that may have injured the carcass, detecting protruding steel cords.

Working principle
A well-trained person is watching the belt running at creep speed.

Remarks
Works only at low speed. Carcass damages without external injuries are hard to detect.

X-RAY (PORTABLE CAMERA)

Used for
Detection of carcass damage.

Working principle
X-ray shots/photographs

Remarks
Excellent resolution. Covers small areas only. Suitable for spot check only.

TRANSMITTER-RECEIVER SYSTEM

Used for
Detection of cover injuries and damages of steel-cords.

Working principle
Site attenuation; decrease of an electric field by electrically conducting materials (the steel-cords).

Remarks
Small cracks can be detected. No real-time monitoring.

LEAKAGE FIELD MEASUREMENT

Used for
Detection of abrupt changes of the steel-cord cross-section.

Working principle
Leakage field measurement.

Remarks
Can be used for speeds of up to 6 m/s. No belt vibration allowed. Quality of analysis depending on software and personal experience.

MAGNETIC RESISTANCE

Used for
Inspection of steel cord conveyor belts right after the production or at certain intervals during the operating time.

Working principle
The steel cords are inductively magnetized (before that they have to be demagnetized).

Remarks
Complicated analysis, vague interpretation.

OPTO-ELECTRONIC IMAGING

Used for
Recording the belt surface condition.

Working principle
Camera systems, laser

Remarks
Limited results under dirty conditions. Belt carcass/steel cords not captured.

X-RAY (STATIONARY, CONTINUOUS)

Used for
Detection of cover and carcass damages, splice deterioration, wear, insufficient cleaning, ripping, foreign objects, material build-up, steel cord failures etc.

Working principle
Permanent X-ray recording of moving belt with image recognition technologies. Permanent and full cross-section X-ray recording.

Remarks
Excellent resolution, detection of any failure, real-time analyses, remote access, automatic reporting.

A comparison between continuous X-ray and magnetic based systems is here.

A video showing the principle of a continuous monitoring system is
here.

PREVENTIVE MAINTENANCE

A four-part article published in Coal Age magazine, May 2016, elucidates the need for preventive maintenance:

"The PM program should successfully avoid premature failures through timely inspection, condition-monitoring and testing. It should help extend equipment life with lubrication, cleaning, adjustment and minor component replacements like belts and filters.
By avoiding premature failures, there will be fewer emergency repairs and more work can be planned because equipment deficiencies will be found long before failure, creating opportunities to plan the work.
Because the resulting planned work is jointly scheduled with operations, it will be performed more productively and carefully by maintenance personnel, whose work will be of higher quality. Higher quality work increases the time needed before the work must be repeated.
As a result, components will have a longer operating life and additional cost savings will be realized by reducing the rate of material consumption."

z2003 Copyright ConveyorBeltGuide.com
z2003 Copyright ConveyorBeltGuide.com