Early FGD systems were designed with separate quenching, or prescrubber, systems to cool the flue gas coming off the particulate control device.
All FGD systems do not cool flue gas.
mnli hypothesis: All FGD systems do not cool flue gas. premise: Early FGD systems were designed with separate quenching, or prescrubber, systems to cool the flue gas coming off the particulate control device.