Rotary driers are most economically designed for the number of heat transfer units (HTU) from _________________?
A. 0.01 to 1
B. 1.5 to 2.5
C. 5 to 10
D. 10 to 20
A. 0.01 to 1
B. 1.5 to 2.5
C. 5 to 10
D. 10 to 20