High efficiency direct-contact high temperature water heater

Abstract

A gas-fired direct-contact water heater system 10 is described. It consists of a first housing 11, 50, 80 having a packing 16, 51, 81 of heat exchange elements 17 and on which water is sprayed. A burner 18, 52, 83 is disposed on the side of the housing under the packing. A combustible gas feed pipe is connected to the burner 18, 52, 83 to provide a combustible gas to the burner. A water collection reservoir 20, 58, 86 is defined below the burner for collecting heated water. A further packing 31-59-91 having heat exchange elements is located in a further housing 30-60-90 and it is also sprayed water. Ambient air is admitted under this packing by a blower 32-63-101 whereby the air is humidified and heated and supplied to the burner for admixture with the gas whereby to obtain a higher combustion product dew point and a reduction in the NO.sub.x emission when burned. A further water collecting reservoir 35, 62-93 is defined in the second housing 30-60-90 below the packing 31, 59, 91 for collecting water percolated through the further packing. Heated water is convected through a first conduit 36, 69, 107 from the water collection reservoir 35, 62, 93 in the first housing. A further conduit 36, 76', 99 is also provided for convecting water from the further housing. The flue gases from the first packing are also cooled in a third packing before being released to atmosphere.

Dependencies are inferred from the claim text.