Abstract: A condensing heat exchange economizer wherein upwardly flowing hot flue gas is apportioned by a damper among a plurality of reverse flow passages and redirected to flow in a downward direction through the reverse flow passages over respective bundles of heat exchange tubes carrying a counter-flowing heat exchange medium to form condensate and cool the flue gas. The economizer may comprise a housing having a main flow duct defining a main flow passage in which the damper is located, a pair of conduits opposing one another across the main flow duct and defining respective reverse flow passages, and a pair of return channels opposing one another across the main flow duct and defining respective return flow passages. The cooled flue gas may be merged with the main flow passage at a location above the damper.

Abstract: A condensing heat exchange economizer wherein upwardly flowing hot flue gas is apportioned by a damper among a plurality of reverse flow passages and redirected to flow in a downward direction through the reverse flow passages over respective bundles of heat exchange tubes carrying a counter-flowing heat exchange medium to form condensate and cool the flue gas. The economizer may comprise a housing having a main flow duct defining a main flow passage in which the damper is located, a pair of conduits opposing one another across the main flow duct and defining respective reverse flow passages, and a pair of return channels opposing one another across the main flow duct and defining respective return flow passages. The cooled flue gas may be merged with the main flow passage at a location above the damper.

Abstract: A condensing heat exchange economizer wherein upwardly flowing hot flue gas is redirected to flow in a downward direction over a bundle of heat exchange tubes carrying a counter-flowing heat exchange medium to form condensate and cool the flue gas, and the condensate is forced by gravity to flow in the downward direction. The economizer may be in the form of a cylindrical economizer adapted for insertion in an exhaust stack for flue gas. The cooled flue gas may be redirected to flow in an upward direction and merged with a primary flow passage leading to the stack.

Abstract: A condensing heat exchange economizer wherein upwardly flowing hot flue gas is redirected to flow in a downward direction over a bundle of heat exchange tubes carrying a counter-flowing heat exchange medium to form condensate and cool the flue gas, and the condensate is forced by gravity to flow in the downward direction. The economizer may be in the form of a cylindrical economizer adapted for insertion in an exhaust stack for flue gas. The cooled flue gas may be redirected to flow in an upward direction and merged with a primary flow passage leading to the stack.