Re: Cross Section Area
Originally Posted by mehdiohadi
which one is true ?
Probably none of them.
All are based on making assumptions about the characteristics of the material handled.
With experience comes knowledge about which formula to use and it usually resides in the brain of an experienced engineer. ■
Re: Cross Section Area
The 20% increase with the DIN value was selected for simplicity way back in the 1940's or before. It was done when hand calculators were not yet invented. CEMA was published in 1966. The original developers could have used DIN but chose to formulate with more precision.
Standards are meant to simplify engineering. Sometimes the simplifications are not adequate for good engineering practice. Thus, the standards leave you to seek the experience factor to define good practices.
We personally prefer CEMA to DIN. The 20% added loading factor is too large a difference to accept. No material loads with such a peak in the crossection. If anything, it is just the reverse as material leaves the turbulent skirt containment region. ■
Surcharge Angle
Dear Nordel
thanks for your attention
I find out that in DIN 22101 has a parameter beta that's not surcharge angle
it's mean is "Equivalent angle of slope for the calculation of the partial cross section A1th" that's why DIN recommended to get beta = 15 deg and when i calculate cross section area with this value, I don't have many different.
With kind regards
Ohadi ■
Cross Section Area
Dear Experts
I have compered cross sectional area with 3 standard and i find out that we have different between DIN 22101 & BS2890.
why?
which one is true ?
For example
Belt width = 1200 mm
Trough angle = 30 deg
Repose Angle = 30 deg
Surcharge Angle = 20 deg
Length of the central idler = 465
in DIN 22101
At = 0.183 m2
in CEMA
A = 0.153 m2
in BS 2890
A = 0.153 m2
Can i rely on to DIN22101 ?
thanks ■