Re: Question about drum roaster design

Andy Schecter wrote: 
jim schulman wrote:

The tenor of the chaper is that virtually all heat transfer is by
convection even in conventional drum roasters.


This is the straw that broke the camel's back. This info is not in the first edition, so I'm going to have to bite the bullet and get the second edition.

Still, the info seems strange. What about heating by radiation? If you hold your hand a few inches below a 500F steel drum, it will indeed feel plenty of radiant heat.

It may be convection from the heat source to the drum but you could say too that the beans receive heat from contact with the drum wall which I don't think it would be correct to call convection. Then the cascade of heated beans into the air in the drum could always be hotter than the air. Since the shape of the bean is sort of round on one side particularly, actual contact is minimal there. A bean shaper would be of benefit in the contact situation. lol
.

Relevant Pages

  • Fun with Roaster Thermography
    ... Prior work on this roaster has included replacing the anemic burner that was ... next roast. ... I wanted to use a tryer to look at beans towards the end of the roasts. ... next roast since I try to let the drum cool off below 400F before new beans ...
    (alt.coffee)
  • Question about drum roaster design
    ... Or in roasterese: if hot air at the same temperature ... is moving past the beans at twice the speed, ... Now I know drum roasters can be speeded up by increading the air ...
    (alt.coffee)
  • Re: Coffee For Less?????
    ... I rather have an basic outdoor gas grill for welding together ... I've considered the BBQ drum and the are a lot of good home roasters who ... you can's see the beans; ... Smoke is diffused before it gets out of the roaster so you really ...
    (alt.coffee)
  • Re: Gene Cafe 1/2 pound roaster question
    ... I watched it mainly to see how to get the hot roasted coffee beans poured ... the drum is removed and the beans dumped by hand. ... end of the cool cycle and dumps the beans into the colander to get ...
    (alt.coffee)
  • Re: aluminum drum for small home roaster ?? will AL work??
    ... Conduction from a solid drum is probably the worst possible ... roasting method and none of the modern commercial roasters rely on ... There is nothing wrong with an aluminum drum per se but it's not used ... support at the front where I want to be able to dump the beans. ...
    (alt.coffee)