Thread subject: Homeroasters - Home Roasting Coffee Community :: Drum Roaster Heat Transfer to Beans

Posted by allenb on 11/24/2018 2:48 AM
#1

A discussion has been ongoing at HRO and other sites about what mode of heat transfer is dominant between conduction, convection and infrared from drum wall depending on specific drum roaster designs. I have contended that with single wall drum, with electric or gas heat being directly applied on the outside of the drum, that IR (infrared), radiating from drum to bean, is dominant over the other two modes and that with all drum roaster designs that heat transfer from conduction is always minimal due to the lack of sufficient contact area of coffee beans.

Still needed to be able to determine to what extent this may or may not be the case, is an accurate reading of drum wall temperature at various locations during a roast. If anyone is able to accurately measure this with a reliable and calibrated IR thermometer, please post your results here and any and all discussion related to this topic is desired.

Allen

Edited by allenb on 12/31/1969 12:00 PM