Re: Belt Flapping Calculation
Originally Posted by raghu
sketch explaining the exact arrangement is attached.
your suggestions on this regard is most necessary.
Namaskar, greetings and salutations from 1,140 feet above mean sea level in my corner
of the Frozen Eastern Widlerness.
If you mean that the top cover and bottom cover end up slapping
each other when the belt is loaded and unloaded yes it would occur.
I would contact Lawrence Nordell at Conveyor Dynamics Incorporated in
Bellingham, Washington through the forum here and have him properly engineer
the corrective design to stop the problem for you. ■
Re: Belt Flapping Calculation
Mr.leon thanks for your reply.but my concern is not about top and bottom cover slap...i am intended to know the occurance of belt flap between those pulleys over a span of around 8-10 meters while the conveyor is running... ■
This Question Has Been Earlier Asked
Dear Mr.Raghu,
Hope the below link may be of your interest.
https://forum.bulk-online.com/showth...highlight=flap
Regards, ■
Belt Flap
Thanks For the link provided by you. Actually i have calculate the belt flap ratio between rotational frequency of pulley (instead of idlers bcoz. my concerned area of belt flap is between fixed tripper bend pulleys as per sketch attached earlier) and natural frequency of belt. Based on the ratio the belt flap occurs in my case. so i decided to provide a idler in the mid span of pulleys and belt flap ratio for the new case(between pulley and idler) is calculated based on rotational frequency of idler. whether the above said solution is seems to be working or will it cause any other adverse effects on the idler. ■
Belt Flap
Thanks for the link provided by you. i calculated the belt flap ratio between the pulleys based on rotational frequency of pulley and natural frequency of belt(based on deflection of belt due to sag) and it falls in node 1. so i have decided to provide an idler in the mid span of pulleys and belt flap ration calculated based on the idler frequency.
Now i am curious to know that there is any adverse effect on the idler as because it is placed between two pulleys due the rotational frequency change (pulley-idler-pulley). or the above said arrangement will solve the belt flapping issue?
experts advise on this regard is much awaited. ■
Re: Belt Flapping Calculation
Mr.Raghu,
Though I am not from design, I suggest you may try pulley-idler-pulley arrangement. The idler may be firmly fixed ( better with plummerblocks ) , so that it may not fall down due to excess flapping, or due to any other reason in future.
It may be fixed outside ( not between the belts ), so that even if it falls, it may not be entrapped between the pulleys & the belt.
You are the better judge, who is physically seeing your site conditions. Please post the result after the job done.
Regards, ■
Calculation Of Belt Flapping
Dear Mr. Raghu,
belt flapping mostly is created by the rotation of idlers. Main influences are therefore
- belt speed
- idler diameter
- idler distance
Influences by the belt come from
- belt weight (and load)
- belt tension
If the stimulating frequency is close to the resonant frequency of the belt, belt flap can occur.
Sometimes this can happen also at other harmonics. So you may have to consider also the "natural frequencies" at a reduce span, changing belt speeds and tensions. Sometimes also belt flap not with the whole mass i.e. only at the belt edges.
Best regards,
Dr.-Ing. Rainer Alles, Germany ■
Belt Flap From Greek Isles?
Originally Posted by Rainer Allesbelt flapping mostly is created by the rotation of idlers. Main influences are therefore
- belt speed
- idler diameter
- idler distance
Influences by the belt come from
- belt weight (and load)
- belt tension
If the stimulating frequency is close to the resonant frequency of the belt, belt flap can occur.
Sometimes this can happen also at other harmonics. So you may have to consider also the "natural frequencies" at a reduce span, changing belt speeds and tensions. Sometimes also belt flap not with the whole mass i.e. only at the belt edges.
Best regards,
Dr.-Ing. Rainer Alles, Germany
I thought you would be basking in the sun with deep tan and love of azur blue sea life, not doing mental gymnastics on belt flap.
His diagram would indicate he has no belt flap problem or at least not damaging. Otherwise, a roller of sufficient bearing capacity, depending on deflection angle, would do it on the outside of the belt loop per Mr. Ganesh. ■
Belt Flap ???
Placing a idler roller on dirty side of belt after discharging material will likely cause build-up of material plated to roller surface. If this happens, it will cause belt flap from induced roller speed and deflection. Not a wise choice. I do not believe you have belt flap from light mass at high angle of belt, unless you have pulley(s) out-of-round. ■
Re: Belt Flapping Calculation
Thanks to all of you for your precious advise.I have compared the natural frequency of belt and rotational frequency of pulley and the ratio does not falls on resonance zone. so i'm assuming that there will be no belt flap and hence no rollers are to be provided. once again thanks for your valuable suggestions. ■
Belt Flapping Calculation
How to find whether belt flap is occurs or not in an fixed tripper. sketch explaining the exact arrangement is attached.
your suggestions on this regard is most necessary.
Attachments
belt snap (PDF)
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