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A fuel-fired, forced draft, down-fired water heater is provided with an improved combustion product flow path that permits the heater to operate with improved fuel efficiency, lowered CO and NOx emissions, and an improved water heat input distribution along the vertical length of the heater. The wat

A fuel-fired, forced draft, down-fired water heater is provided with an improved combustion product flow path that permits the heater to operate with improved fuel efficiency, lowered CO and NOx emissions, and an improved water heat input distribution along the vertical length of the heater. The water heater includes a vertically oriented tank with a vent plenum structure formed at the top end of the tank interior and having an outlet passage connectable to an external combustion product vent pipe. A centrally positioned submerged vertical burner tube extends downwardly from the vent plenum and has an open lower end extending into a submerged turn bowl disposed at the bottom end of the tank interior. Extending upwardly from the turn bowl within the tank interior, and symmetrically arranged about the centrally disposed burner tube, are a plurality of vertical flue tubes that communicate the interiors of the turn bowl and the vent plenum. A suitable fuel burner is disposed within the burner tube and is supplied with a throughflow of a pressurized fuel/air mixture which is ignited to create a downwardly directed flame and associated hot combustion products. During operation of the water heater, the hot combustion products are sequentially flowed downwardly through the burner tube into the submerged turn bowl, upwardly through the flue tubes into the vent plenum, and then outwardly through the vent plenum outlet passage.

대표청구항 ▼

A forced draft, fuel-fired water heater comprising: a vertical tank centered about a vertical axis and having an internal chamber adapted to hold a quantity of water, said tank having a top end, a bottom end, an inlet for receiving pressurized water to be heated within said internal chamber, and an

A forced draft, fuel-fired water heater comprising: a vertical tank centered about a vertical axis and having an internal chamber adapted to hold a quantity of water, said tank having a top end, a bottom end, an inlet for receiving pressurized water to be heated within said internal chamber, and an outlet for discharging pressurized heated water from said internal chamber; a vent plenum structure formed within a top end portion of said tank, downwardly adjacent the underside of said top end thereof, and defining a top end boundary of said internal chamber, said vent plenum structure having an outlet passage extending outwardly through said tank and connectable to an external combustion product vent pipe; an enclosed, hollow turn bowl structure disposed within a lower end portion of said internal chamber, said hollow turn bowl structure being centered about said vertical axis and having a top side wall and a bottom side wall; a vertically oriented burner tube extending through said internal chamber along said vertical axis, said burner tube having an upper end positioned adjacent said top end of said tank, and a lower end portion extending downwardly through said top side wall of said turn bowl structure and opening into the interior of said turn bowl structure; a plurality of vertically oriented flue tubes extending through said internal chamber in a symmetrically spaced array extending outwardly around and centered about said burner tube, said flue tubes having open upper end portions extending through the underside of said vent plenum structure and opening into the interior of said vent plenum structure, and open lower end portions extending through said top side wall of said turn bowl structure and opening into the interior of said turn bowl structure, each of said flue tubes, said burner tube and said turn bowl structure, during operation of said water heater, being submerged in and in intimate heat transfer contact with water within said internal chamber of said tank; burner means extending downwardly through an upper end portion of said burner tube and being operative to receive a pressurized fuel/air mixture from a source thereof, and ignite the received fuel/air mixture to form hot combustion products which are sequentially flowed downwardly through said burner tube into said turn bowl structure, upwardly through said flue tubes into said vent plenum structure, and then outwardly through said outlet passage of said vent plenum structure; and fuel/air delivery means operative to flow a pressurized fuel/air mixture to said burner means, said bottom end of said tank being defined by an upwardly domed bottom head structure, said turn bowl structure being supported atop said bottom head structure by a vertically oriented hollow cylindrical support column centered about said axis, and said water heater further comprising a condensate drain tube centrally extending downwardly from said turn bowl structure through the interior of said support column into said bottom heat structure and having an interior communicating with the interior of said hollow turn bowl structure.