Abstract: A dual direct contact water heater is described and consists of a heater housing having two sections, each section having a water reservoir. One section provides hot water at a high temperature and provides a source of heat exchange to heat an external source of water for commercial use. A burner is provided in the first section to provide the heat source to a packing through which water percolates. The source of water for the first section is the outlet of a heat exchanger whereby water from the reservoir is recirculated in a closed circuit in the first section. Hot gases rising from the first section is directed to a second section which also includes a second packing and a reservoir and it also has a closed loop whereby a second source of hot water, at a lower temperature, is utilized in a closed loop and in heat exchange with a second external source to produce domestic hot water or without heat exchanger to produce hot water for various processes.

Abstract: A gas-fired water heater is comprised of a vertical housing (11) having a circumferential side wall (12), a closed bottom end (13), and a flue (14) connected to a top end portion (15) thereof. A packing (17) of heat exchange elements (18) is supported inside the housing (11) in an uppermost region (19) thereof. A water discharge orifice or nozzle (21) is disposed above the packing (17) and connected to a water supply (22) for releasing water to be heated on the packing. An axial burner (23) is disposed substantially centrally with the housing under the packing (17). A feed pipe (24) is connected to the burner (23) and extends at least partly axially within the housing. A gas-air mixture is fed to the burner (23) through the feed pipe (24). An ignitor device (25) is provided to ignite the burner (23).