Belt conveyors. Transition Distance for Head and Tail Terminals 1

[vkcat]

Hi all.
CEMA book gives transition distance for Head and Tail terminals - from the Pulley to the First Troughing Idler - 20, 35 etc degrees.

Question is.

Using 35 degree Idlers, Belt Width 30", in transition we using 20 degree idlers.
What is the right way to find position for 20 degree idler between Pulley and First 35 degree idler?

(Tension rate I think, in range 60-90%)

Thanks in advance,
vkcat.

 

[dvd]

To get fully confused on this you should read more. Try this article, it is interesting, even though it doesn't answer your question.

http://www.pooleyinc.com/pdf/TechArticle.pdf

If you look at the CEMA table values and see what the transition distance is for a 20deg idler vs 35deg idler, that might be a good place for the 20deg intermediate idler in a 35deg transition.

I have often wondered why a 20deg idler is used as an intermediate idler in a 35deg transition, as opposed to using another 35deg idler which has a wider center roller that would keep a straight line from fully formed belt profile to flat profile at the pulley. I don't know how the 20deg intermediate idler came to be used.

 

[vkcat]

[quotes]To get fully confused on this you should read more. Try this article, it is interesting, even though it doesn't answer your question[/quotes]

Thanks
This article in my desktop now

 

[PersonalProfile]

This enquiry may yield more results in another "sub" forum, or another forum altogether [e.g. bulk-solids.com].

I pro rata the angle change / distance to specify its location, e.g. 35 - 0 degree / Transition Length [TL] = degrees / TL, rearranging, TL20 = degrees / TL * 20 degrees.
I also require contractor to verify the installation with stringlines etc.
You will need to confirm that the transition length that you have selected is appropriate, and so are the idler spacing [with regards to: sag / spillage, and idler loads etc].

Others have completed more applied analysis, including the following reference, that may be of interest:

Beckley, D, 1982, Belt Conveyor Transition Geometry, Bulk Solids Handling, vol.2, no. 4, pp. 727-731.

Regards,
Lyle