Procurement Gone Astray.
Originally Posted by subhashisskyisthelimit
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As per belt catalogue of internationally reputed belt manufacturers, troughability of belt with a belt rating of 630/4 is okay.
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An internationally reputed belt manufacturer should have access to a test rig which is built to evaluate the ISO/DIN properties in regard to troughing ability. Was the troughing ability questioned, confirmed or observed before ordering the belt? Troughing ability of 630/4 means nothing. What was the carcass construction etc, etc.
In the second question '... Belt rating is not yet decided.' any further comment would be irrelevant.
But, if the belt in question 1 is not touching the centre rolls have you considered putting them in store for a rainy day? ■
John Gateley johngateley@hotmail.com www.the-credible-bulk.com
Fitting To Order
Dear Guest,
I trust that you
a) talk about the troughing-in distance only
b) the idler within the troughing-in area have adjustable wing rolls
You might then consider
- fitting the idler to the belt position, i. e. to lift the idler until the center roll touches the belt
- to adjust the angle of the wing rolls to the troughing-in contour of the belt
Else you might purchase such idlers.
As for an in-depth analysis of the root cause, there's more parameters to be considered as well as some calc. work t. b. done... which is paid work and I'm quite convinced you or smbdy around you have the appropriate contact at hand. As per your post I kindly invite you to consider calling for expert input.
Kind regards
R. ■
Being Specific
Dear Experts,
First of all,I acknowledge with thanks for your valuable feedback -Mr. john gateley and Mr. Roland Heilmann.
In response to Mr. Gateley's comment, I would like to explain that the belt is of N-N carcass,FR grade.
I understood that the cover thicknesses being on a higher side, would add more stiffness to the belt.Should it be a criteria to be considered while discussing this issue?
It would be really appreciated if you also share your thought on the Transition distance with respect to T.C. and B.C. as per question no.2 for both Steel cord( ST-1400) and N-N (1600/4)Belt.
I would welcome your valuble feedback/advise/experience on the subject matter.
Thanks,
Subhashis Dey ■
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Dear Mr. Subhashis Dey,
troughability is dependend upon
- belt width, belt mass --> improve tr.
- tension member thickness --> impair tr.
- transverse rigidity properties, transverse reinforcements --> influence t. b. clarified
In my opinion your first conclusion is not correct.
You describe above that the troughability was checked by design instance based on general suppliers database but then on site did not satisfy requirements. Conclusion is, either operational environment is not to requirement or design instance has erred or equipment is not as previewed. Concluding: this is a multiparameter issue which cannot be solved from afar or even by some internet questioning, you need professional support on site. Pls. adjust your issue solving strategy
Kind regards
R. ■
Basics.
ISO 703:2017 specifies a test method for determining the transverse flexibility (troughability) of a conveyor belt, expressed as a ratio, F/L. The method is not suitable or valid for light conveyor belts as described in ISO 211831.
This standard should have been included in the original specification. Without it you are similar to Oscar Pretorius.
As previously mentioned internationally reputed belt manufacturers should have access to the required test facilities. When buying serious quantities of belting it is incumbent on the purchaser to ensure compliance via QC. Often enough the QC doesn't have clue: if he had a clue he would become a designer! ■
John Gateley johngateley@hotmail.com www.the-credible-bulk.com
Re: Belt Transition Distance And Troughability Of Conveyor
Hello,
The troughability of particular type of belt depends upon carcass thickness.
The textile (EP and NN type) belt 630/4 carcass can have differing thickness depending upon whether belt is of category-1 or category-2 or category-3; which are often named as light duty (or standard duty) or medium duty or heavy duty. Such categories arises in context of inter-ply rubber thickness.
The belt troughability value can differ some what among makes, depending upon their carcass specific thickness and in addition intrinsic quality of rubber, polyamide and polyester, as applicable to particular make.
Whether the troughability of one make (or publication) can be applicable to other make defecto ?? It depends upon the belt supply agreement.
One option is you may try to run conveyor hoping that belt stiffness will diminish after some use and everything ends happily. Also when material is loaded, belt may trough properly and convey material as per need, fulfilling the requirement.
Above to be treated as general information without any relevance to your contractual aspects.
Ishwar G. Mulani
Author of Book: ‘Engineering Science And Application Design For Belt Conveyors’. Conveyor design basis is ISO (thereby book is helpful to design conveyors as per national standards of most of the countries across world). New print Nov., 2012.
Author of Book: ‘Belt Feeder Design And Hopper Bin Silo’
Advisor / Consultant for Bulk Material Handling
System & Issues.
Pune, India. Tel.: 0091 (0)20 25871916
Email: conveyor.ishwar.mulani@gmail.com
Website: www.conveyor.ishwarmulani.com ■
Re: Belt Transition Distance And Troughability Of Conveyor
Hello,
I add following information in context of my earlier reply.
The belt manufacturers information about troughability do not give separate values attributed to cover thickness. So we can presume as below:
- Their stated troughability of belt already accounts for normal cover thickness say 6 mm and 3 mm etc.
- The abnormal cover thickness will certainly reduce troughability by some margin, but it may not be decisive because there is no mention about it.
- The belt troughability accounting abnormal cover thickness, can certainly be ascertained by belt manufacturer by sample test if required. Or one can also calculate the influence by using modulus of elasticity for rubber and carcass (transverse) and using composite beam formula, for deflection (troughability) under gravity force .
Ishwar G. Mulani
Author of Book: ‘Engineering Science And Application Design For Belt Conveyors’. Conveyor design basis is ISO (thereby book is helpful to design conveyors as per national standards of most of the countries across world). New print Nov., 2012.
Author of Book: ‘Belt Feeder Design And Hopper Bin Silo’
Advisor / Consultant for Bulk Material Handling
System & Issues.
Pune, India. Tel.: 0091 (0)20 25871916
Email: conveyor.ishwar.mulani@gmail.com
Website: www.conveyor.ishwarmulani.com ■
Re: Belt Transition Distance And Troughability Of Conveyor
Here Sharu
We also doing belt manufacuring, My suggestion is to get ISO 9001 Certification first and we go for other certification, You can go with EAS to Get best ISO Certification Cost ■
Re: Belt Transition Distance And Troughability Of Conveyor
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Belt Transition Distance and Troughability of Conveyor
Question 1
In a specific plant, following are the parameters of set of conveyors:
Belt width is 600 mm, trough angle is 350, Belt rating is 630/4, top cover is 7.5 mm & bottom cover is 7.5 mm. Top & Bottom cover are as per requirement of customer and not decided by loading cycle consideration.
As per belt catalogue of internationally reputed belt manufacturers, troughability of belt with a belt rating of 630/4 is okay. Hence designer okayed the selection of the belt.
But actually the belt is not touching the central idler throughout the length.
Question is
Should the top & bottom cover of the specific belt being very high (not required as per loading calculation) have an influence on troughing criteria? And do you wish to revisit the troughability of 630/4 recommendation?
Question 2
In another plant, belt width is 2000 mm. Belt rating is yet not decided, troughing angle is 350. And Customer wants 8 mm top cover. Obviously, the bottom cover can be 3mm and above.
Question is
Will the transition distance at head & tail end have any impact due to such top & bottom cover? Will it not add stiffness to the belt? I mean the cover thickness shall have any influence on the transition distance? ■