ABSTRACT
O? If the coal burns heterogeneously under diffusion control and if its density is 1300 kg/m
, what is the burning time for 75-
µ
m particles? If the velocity of coal and gas is 15 m/sec, what is the combustor length required for complete combustion? (Note that boilers fire pulverized fuel (pf) suspensions with 75% of mass passing through a 75-
µ
m sieve.)
Problem 9.5:
Activated carbon is manufactured from corn fiber. First, corn fiber is densified and then fed into rotary kilns for carbonization at 700 to 1000
°
C. The resulting corn char is activated in H
O/CO
/O
at 700 to 1000
°
C to get the desired pore structure and (large) internal surface area.
