Draft CEMA Standard - Bulk Material Belt Conveyor Cleaner Application Ranking – Revision 2 – August 11, 2011
Bulk Material Belt Conveyor Cleaner Application RankingDRAFT
Prepared by
The Bulk Belt Conveyor Accessories Committee
of the
CEMA Engineering Conference
Sub-committee members:
Brett DeVries – Flexco
Judd Roseberry – Richwood
Joseph Roell – Argonics, Inc
Greg Westphall – Flexco
Corrie Godee – Metso
Todd Swinderman – Martin Engineering
John Barickman – Martin Engineering
Michael Heenan -- ASGCO
Draft CEMA Standard - Bulk Material Belt Conveyor Cleaner Application Ranking – Revision 2 – August 11, 2011
DISCLAIMER
The information provided in this document is advisory only. These recommendations are provided by CEMA in the interest of promoting safety in the work place. These recommendations are general in nature and are not intended as a substitute for a thorough safety program. Users should seek the advice, supervision or consultation of qualified engineers or other safety professionals. Any use of this document, the information contained herein, or any other CEMA publication may only be made with the agreement and understanding that the user and the user’s company assume full responsibility for the design, safety, specifications, suitability and adequacy of the system component, or mechanical or electrical device designed or manufactured using this information. The user and the user’s company understand and agree that CEMA, its member companies, its officers, agents and employees shall not be liable in any manner under any theory of liability for the user or user’s reliance on these recommendations. The users and the user’s company agree to release, hold harmless and indemnify CEMA, its member companies, successors, assigns, officers, agents and employees from any and all claims of liability, costs, fees (including attorney’s fees), or damages arising in any way out of the use of this information. CEMA and its member companies, successors, assigns, officers, agents and employees make no representations or warranties whatsoever, either express or implied, about the information contained in this document, including, but not limited to, representations or warranties that the information and recommendations contained herein conform to any federal, state or local laws, regulations, guidelines or ordinances.
This standard has been established to provide uniformity of selecting duty class among the various manufacturers of conveyor belt cleaning devices.
This standard implies no representation that a particular belt cleaner is suitable to be used in combination with a particular conveyor belt.
This standard implies no representation that a particular belt cleaner is suitable to be used in combination with a particular conveyor belt splice.
Each manufacturer is responsible for the design of their product including the suitability for use in applications where food handling,corrosion resistance, fire retardant or anti-static features may be required by statute or application.
The use of Conveyor Belt Cleaners may increase the horsepower requirements of the conveyor drive. Contact a CEMA member for information.
Conveyor Belt Cleaners may be required to meet additional industry or government standards or requirements such as for use in underground mines, hazardous locations, or for food handling that are not spelled out in this standard. Contact a CEMA member for information.
CEMA reserves the right to revise this standard at any time without notice.
FOREWORD
Conveyor belt cleaners are used to remove fugitive material, otherwise known as carryback, from the head pulley and return side of the conveyor belt after the bulk material has been discharged. Ideally, this will be accomplished from within the chute works so that the removed carryback will pass onto the next system element. However, other locations may also be suitable. It is understood that the methods and designs for cleaning belts are numerous.
This standard has been established to provide a uniform method for determining the duty class of the application. This duty class will assist in the selection of an appropriate Conveyor Belt Cleaner or Conveyor Belt Cleaner system for the application. By ranking the application, guidance concerning the ruggedness and durability of the needed Conveyor Belt Cleaner will be provided. Manufacturers voluntarily specify into which class their particular designs fall.
This standard assumes the application ranking will consider the conveyor belt to be in “new” or “as new” condition.
This standard makes no statement regarding the cleaning performance or life of any particular Conveyor Belt Cleaner. Contact a CEMA member for information.
Bulk Material Belt Conveyor Cleaner Application Ranking DRAFT
Prepared by
The Bulk Belt Conveyor Accessories Committee
of the
CEMA Engineering Conference
CONVEYOR EQUIPMENT MANUFACTURERS ASSOCIATION
6724 Lone Oak Blvd.
Naples, Florida 34109
(239) 514-3441
Fax: (239) 514-3470
E-Mail:
Web Site:
Standard No. ??? - Copyright ????
Conveyor Equipment Manufacturers Association
DatabaseID=2B55274D20203421244B5220|ContactID=5F5650522020465B27572521|RANKING AND CLASS SYSTEM
The application severity for selecting a Conveyor Belt Cleaner is rated using the following factors.
- Belt Width
- Belt Speed
- Quantity and type of belt splices
- Abrasiveness of the material
- Stickiness/moisture content of the material
For the purposes of this ranking conveyor belts must be new or in “as new” condition.
DatabaseID=2B55274D20203421244B5220|ContactID=5F5650522020465B27572521|METHOD
Each of the five factors is rated individually. CEMA standard 550 is a valuable tool for assigning values to the various categories. The final application score is the sum of all five factors. The final score is divided into five duty class levels and should be specified when Conveyor Belt Cleaners are being selected. A Conveyor Belt Cleaner rated to at least equal to the calculated duty class score should be selected. An explanation of the factors appears below.
BELT CHARECTERISTICS
Belt Width
ScoreDescription
0<24” width (600mm)
124”– 47” width (600mm – 1199mm)
248”– 71” width (1200mm – 1799mm)
472”– 96” width (1800mm – 2400mm)
8>96” width (>2400mm)
Belt Speed
ScoreDescription
1<300 fpm (1.5 m/sec)
2300 – 600 fpm (1.5 – 3.0 m/sec)
4601 – 1000 fpm (3.1 – 5.0 m/sec)
8>1000 fpm (>5.0 m/sec)
Splice Type
ScoreDescription
0vulcanized (for the entire life of the belt)
2 vulcanized with temporary mechanical splices
4one or two mechanical splices
8more than two mechanical splices
MATERIAL CHARECTERISTICS
Abrasiveness
ScoreDescription
1Mild(CEMA Standard 550 code 5, Abrasive index 1-17)
2Medium(CEMA Standard 550 code 6, Abrasive index 18-67)
4Severe(CEMA Standard 550 code 7, Abrasive index 68-416)
Stickiness/Moisture Content(choose the worst case expected conditions in situations where the conditions will vary)
ScoreDescription
1Mild/Dry (<2% moisture by weight)
2Medium/Moist (2-8% moisture by weight)
4Heavy/Wet (>8% moisture by weight)
8Severe/Wet slurry with fines (CEMA 550 code F, O, V))
The sum of the individual scoresis broken down into the following ratings.
APPLICATION SEVERITY DUTY RANKING
ScoreDescription
≤ 6Class 1
7-10Class 2
11-15Class 3
16-23Class 4
24+Class 5
EXAMPLES
IMPERIAL
A conveyor designer needs to choose belt cleaners for a conveyor carrying limestone from the quarry pit. The conveyor width is 36” and the belt speed is 420’ fpm. The belt will be installed with a vulcanized splice but will be spliced mechanically with up to two splices simultaneously during its life.
Referring to the Belt Width chart a score of 1 for the 36” width is assigned.
From the Belt Speed chart a score of 2 is assigned.
From the Splice Type chart a score of 4 is assigned since this belt will typically have two mechanical splices in it even though it is vulcanized at commissioning.
Referring to CEMA Standard 550, the CEMA material code is 75A4046MY which contains 6 as the abrasiveness rating for limestone. From this, a score of 2 is assigned.
From the Stickiness/Moisture Content table, a score of 4 is assigned. Even though the majority of the time this material will run fairly dry, groundwater or heavy rain can make the pit very wet. A conservative ranking would assume wet conditions.
The total score would be 1+2+4+2+4=13. From the Application Severity Duty Ranking Chart, the designer would select conveyor belt cleaners that fall in at least the Class 3 category.
METRIC
A designer needs to choose belt cleaners for a new conveyor in a terminal expansion. The material conveyed will be clean bituminous coal on an 1800mm wide belt at 4.1 m/s. The site specified a vulcanized splice for all belts.
Referring to the Belt Width chart a score of 4 for the 1800mm width is assigned.
From the Belt Speed chart a score of 4 is assigned.
From the Splice Type chart a score of 0 is assigned since this belt will be vulcanized throughout its life.
Referring to CEMA Standard 550, the CEMA material code is 50D335LNXY which contains 5 as the abrasiveness rating for bituminous coal. From this, a score of 1 is assigned.
From the Stickiness/Moisture Content table, a score of 2 is assigned. Rain and anti-dust measures could result in extra moisture in the coal. A conservative ranking would assume moist conditions.
The total score would be 4+4+0+1+2=11. From the Application Severity Duty Ranking Chart, the designer would select conveyor belt cleaners that fall in at least the Class 3 category.
END OF DOCUMENT