Re: Wrap Resistance Between Conveyor Belt And Pulleys - Papers…
Originally Posted by dkaszuba
my name is Damian Kaszuba and my PhD work at the WRUT is about wrap resistance between conveyor belt and pulleys. I am searching for papers, research or simply advice regarding this topic.
I was unable to find any research into this type of belt conveyor resistance however I have found some equations to calculate it and graphical method for estimation.
Mentioned equations are as follows:
Equation 1:
- wrap resistance for fabric carcass belts Fl=9B[140+0,01(T/B)]db/D,
- wrap resistance for steel cord carcass belts Fl=12B[200+0,01(T/B)]db/D,
where:db - belt thickness, m, D - pulley diameter, m, T - average belt tension at pulley ((T1+T2)/2), N, B - belt width,
source: BS5934:1980/ISO5048:19979, book written by Golka,Bolliger,Vasili titled "Belt Conveyors Principles for calculation and design" from 2007 and book by Tadeusz ur a Polish scientist but within the equation the 140 is changed for 137 and 200 is changed for 196.
Equation 2 (very similar):
- wrap resistance for fabric carcass belts Tp(1)=9b(0.8+0,01(T/b)Bt/Dp,
- wrap resistance for steel cord carcass belts Tp(1)=12b(1.142+0,01(T/b)Bt/Dp,
where:b - belt width, m, Bt - belt thickness, m, Dp - pulley diameter, m, T - belt tension at pulley, lbs,
source: CEMA 5th edition.
Graphical method for quick estimate of Tp
The total tension to rotate pulleys is read from the graphs on the belt tension at pulley. It is an estimation and can be used only to estimate the range of wrap resistance.
Thank You in advance,
Best Regards!
PS. If my english in unclear i am verry sorry for that. I will explain any doubts in case of difficulties understanding what I had in mind.
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I do not know exactly what your wrap resistance is trying to identify and am not familiar with your distilling the above, but, can tell you it seems to lack many variables: a) bottom cover thickness, b) pulley lagging type, geometry, properties, c) range of ambient conditions, d) wrap arc, e) driven and non-driven type pulleys, f) secondary cover reinforcements, g) type of bottom cover rubber and its temperature dependent properties, h) idler to pulley transition geometry, i) .........
I suggest you read the older work of Hohman and Zedes. The later is an extension of Hohman's earlier work. There may be others that followed Zedes. Zedes did his PhD at Hannover University in Germany. His theory and experimental work included instrumenting pulleys to track the change in belt tension and surface friction as a function of wrap angle and belt tension. It gives very good insight on the reduction in surface friction with the many variables at play.
Please advise when you have read it and tell us what difference it makes in your study vs. the above simple equations you note.
Good Luck,
Lawrence Nordell
Partner
Conveyor Dynamics, Inc.; Comminution Technology, LLC.; Granular Dynamics, LLC, ROCKY-DEM, Inc. ■
Re: Wrap Resistance Between Conveyor Belt And Pulleys - Papers…
Hello!
Thank You, I will try to get to publications made by authors You mentioned. By now I had many difficulties with getting to any research/publications made into this component of belt conveyor resistance to motion.
All the factors that You mentioned are very important moreover the equations that I have found do not take belt width B into account. At my University is test stand built to measure wrap resistance between two pulleys but unfortunately it offers constant wrap angle (2 X 180 degrees) and pulleys diameter. I have tested two samples of steel cord belts with the same carcass and covers thickness the only difference was that covers was made of different rubber. The result was that the rubber used for covers has impact on wrap resistance.
I am also going to do some research at the test stand for measurement of wrap/bending resistance at another faculty at my University which allows to measure the wrap/bending resistance for diameter from 0,4 to 1,5 m. The trick is to get enough samples for my tests to check all the factors that have impact on the wrap/bending resistance.
Best Regards!
Damian Kaszuba ■
Wrap resistance between conveyor belt and pulleys - papers/research/suggestions
Dear forum members,
my name is Damian Kaszuba and my PhD work at the WRUT is about wrap resistance between conveyor belt and pulleys. I am searching for papers, research or simply advice regarding this topic.
I was unable to find any research into this type of belt conveyor resistance however I have found some equations to calculate it and graphical method for estimation.
Mentioned equations are as follows:
Equation 1:
- wrap resistance for fabric carcass belts Fl=9B[140+0,01(T/B)]db/D,
- wrap resistance for steel cord carcass belts Fl=12B[200+0,01(T/B)]db/D,
where:db - belt thickness, m, D - pulley diameter, m, T - average belt tension at pulley ((T1+T2)/2), N, B - belt width,
source: BS5934:1980/ISO5048:19979, book written by Golka,Bolliger,Vasili titled "Belt Conveyors Principles for calculation and design" from 2007 and book by Tadeusz ur a Polish scientist but within the equation the 140 is changed for 137 and 200 is changed for 196.
Equation 2 (very similar):
- wrap resistance for fabric carcass belts Tp(1)=9b(0.8+0,01(T/b)Bt/Dp,
- wrap resistance for steel cord carcass belts Tp(1)=12b(1.142+0,01(T/b)Bt/Dp,
where:b - belt width, m, Bt - belt thickness, m, Dp - pulley diameter, m, T - belt tension at pulley, lbs,
source: CEMA 5th edition.
Graphical method for quick estimate of Tp
The total tension to rotate pulleys is read from the graphs on the belt tension at pulley. It is an estimation and can be used only to estimate the range of wrap resistance.
Thank You in advance,
Best Regards!
PS. If my english in unclear i am verry sorry for that. I will explain any doubts in case of difficulties understanding what I had in mind. ■