CEMA Conveyor Belt Cleaning Efficiency Ranking - First Draft - May 17, 2011

CEMA Conveyor Belt Cleaning Efficiency Ranking - First Draft - May 17, 2011

CLEANING EFFICIENCY RANKING

FOREWORD

Conveyor Belt Cleaners are one of the last items used on a bulk conveyor belt where the performance is not quantified. Motors, gearboxes, belts, idlers and impact beds all have measurable performance levels and capacities, but Conveyor Belt Cleaners do not. As the voice of the North American conveyor industry, the current situation should be seen as challenge for CEMA Bulk Conveyor Accessory members to provide guidance to the industry.

BACKGROUND

As the world market for new conveyors becomes increasingly interwoven and fugitive material capture becomes more critical to the conveyor design firm, the lack of a quantified belt cleaner performance standard becomes a concern. Design firms are tasked with achieving belt cleaning standards and do not have an industry accept method for meeting the requirement.

Conveyor Belt Cleaner manufacturers could also benefit because an industry standard method to calculate the savings in material and cleanup cost could be used in dialog with end users to show the benefit of Conveyor Belt Cleaners.

Safety in the industry would be enhanced with increased use of Conveyor Belt Cleaners since a significant number of injuries and fatalities occur annually from persons cleaning up fugitive material while in close proximity to the belt. Quantified Conveyor Belt Cleaner performance would allow for a calculable number of reduced hours spent cleaning up and thereby a reduction of time spent by personnel in hazardous locations.

OBSTACLES

Belt cleaner performance can vary based on factors outside the control of the manufacturer, so it is a scary exercise to guarantee performance as a general case. Probably performance would have to be rated under controlled inputs and conditions, but this may render the standard impractical to the industry.

There is no agreed upon measurement technique for measuring performance. There exist some techniques different manufacturers have used internally, but all have challenges and drawbacks. One of the first challenges in creating a performance standard would be to create a test method for measuring performance levels.

Performance level testing so far has been difficult, time consuming and expensive. In addition, there is no cost benefit to an end user from testing cleaner performance. CEMA should not create a standard that is just seen as an additional cost to the end user. Can a standard be created in such a way that in situ performance testing is not required and rarely performed, if ever?

Many conveyor belts are cleaned with multiple cleaners otherwise known as a system. It may become cost prohibitive to determine the rating for multiple systems.

If the all the above obstacles can be overcome, the following classification system is submitted as a baseline for further consideration.

CLEANING EFFICIENCY RANKING

Cleaner system performance could be ranked on a sliding scale.

Class I:>.05 lbs/ft2 (>250 g/m2)

Class II:.02 lbs/ft2– .05 lbs/ft2 (100 – 250 g/m2)

Class III:.002 lbs/ft2 – .02 lbs/ft2 (10 – 100 g/m2)

Class IV:.0004 lbs/ft2 – .002 lbs/ft2 (2 – 10 g/m2)

Note: The highest levels of cleaning are not possible on all belts. The above classifications are based on new or “as-new” belt. Highest classification levels are dependent on belt condition, belt speed, and moisture content. In some cases additional water may need to be applied to the belt to achieve desired classification level. Consult a CEMA member company for assistance.

These values can be converted to tons per hour of carryback by the following method:

Class * Material path width (in) * belt speed (fpm) ÷ 400 = tons per hour(imperial)

Class * Material path width (m) * belt speed (m/sec) ÷ 278 = metric ton/hour(metric)

Class * Material path width (m) * belt speed (m/sec) * 3.6 = kg/hour(metric)

With this system, it is an easy calculation to determine the appropriate cleaning class desired based on tons per hour of carryback. Once in tons per hour, it is more easily appreciated by the engineer or the site how much maintenance will be needed on the conveyor line to remove the accumulated carryback.

Sub-committee members:

Brett DeVries – Flexco

Judd Roseberry – Richwood

Joe Roell – Argonics, Inc

Greg Westphall – Flexco

Corrie Godee – Metso

Todd Swinderman – Martin Engineering

Justin Malohn – Martin Engineering

George Mott – ASGCO

Michael Heenan -- ASGCO

THE VOICE OF THE NORTH AMERICAN CONVEYOR INDUSTRY