customize a new roasting machine

[heshamabubaker]

Dear All,

i am starting a new specialty coffee roastery and we have a local manufacturer that builds a coffee roasting machines and i can customize and add whatever i want to the machine.

my machine will be 15 kilos with 4 motors.
the face and the back of the drum will be cast iron.
Bottom fired, natural gas.


and i have these questions:

what is the best Drum material?

How thick the drum wall should be?

if i want to make a double wall drum, what is the thickness of the 2 walls and what is the space between the 2 walls should be?

what is the deference between Burner atmospheric, power burner,infra-red or recalculating??

Amount and size of Exhaust??

How the blades must be configured ??

Chaff collector designs??

Push or Pull exhaust systems??

if any body have a pictures of the roaster design please provide me with.

thanks for all.