A paper machine configured as a swing machine capable of producing both
light and heavy grades providing a Yankee hood split into a wet end half
and a dry end half, at least one hood half being a flex-hood half wherein
the supply for that half is capable of being run with either combustion
heat or recycled heat and is capable of either recirculating the exhaust
from the hood or discharging it to the atmosphere. The heater for the
flex-hood half comprises both a primary combustion heat source and an
indirect heat source capable of extracting by-product heat from another
operation. The exhaust system for the flex hood half is capable of being
run in either a straight through mode or in a recirculating mode.