decussate or spiral (Figure 1). Most prevalent in nature are spirals in which the average divergence angles between successive organs are close to 137.5° type "C" for light duty and type "D" for heavy duty. The mechanism and tank of both units are of sturdiest construction to meet the need for 24 hour a day service. Both type "C" and type "D" Rake Classifiers ...The most distant period in time for which we have estimated CO2 levels is around the Ordovician period
