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US 2011/0214621 A1Published application
High efficiency gas-fired water heater
AssigneeRheem Manufacturing Company
InventorsJozef Boros, Qian Zhang, Yoshiki Semba, Subbu Thenappan
Life of this patent
Estimating the term…
Abstract
The efficiencies of illustrative embodiments of vertical center flue type fuel-fired base water heaters are improved by installing in the water heaters variously configured tubular condensing type secondary heat exchangers of smaller diameters than the associated center flues. The efficiency increases are achieved with components and manufacturing processes similar to those utilized in the base water heaters and secondary heat exchanger materials similar to those in the tank portions of the base water heaters.
Claims42
Fuel-fired liquid heating apparatus comprising:
- a tank adapted to hold a quantity of liquid to be heated, said tank having upper and lower ends;
- a primary flue longitudinally extending vertically through the interior of said tank, said primary flue extending between and being connected to said upper and lower ends of said tank;
- a secondary flue longitudinally extending vertically through the interior of said tank, said secondary flue having a total surface area exposed to the interior of said tank, an upper end portion coupled to said primary flue adjacent said upper end of said tank and further having a vertically coiled lower end portion substantially entirely disposed in a lower portion of said tank;
- and
- a fuel-fired combustion system operable to flow hot combustion products sequentially through said primary flue and said secondary flue to transfer combustion heat therethrough to liquid disposed in said tank,
- the percentage ratio of the surface area of said lower end portion of said secondary flue to said total surface area of said secondary flue exposed to the interior of said tank being in the range of from about sixty percent to about ninety percent.
3 more elements
A fuel-fired water heater comprising:
- a tank adapted to hold a quantity of pressurized water to be heated, said tank having upper and lower ends;
- a combustion chamber disposed beneath said lower end of said tank;
- a tubular primary flue longitudinally extending vertically through the interior of said tank and communicating with the interior of said combustion chamber, said primary flue having a capped upper end portion extending upwardly through and connected to said upper end of said tank, said primary flue further having a lower end connected to said lower end of said tank and communicating with the interior of said combustion chamber;
- a fuel burner disposed within said combustion chamber and operative to receive fuel and air from sources thereof and combust the fuel and air to create hot combustion products that are flowable upwardly through said primary flue;
- and
- a tubular secondary flue disposed within said tank and operative to receive hot combustion products from said primary flue, said secondary flue having an inlet portion connected to an upper end portion of said primary flue, and a vertically coiled section disposed beneath said inlet portion and wrapped around said primary flue, said coiled section vertically extending only through a lower portion of the interior of said tank, said secondary flue having a diameter smaller than the diameter of said primary flue.
3 more elements
Fuel-fired liquid heating apparatus comprising:
- a tank adapted to hold a quantity of liquid to be heated, said tank having upper and lower ends;
- a combustion chamber associated with said tank;
- a tubular primary flue longitudinally extending vertically through the interior of said tank and communicating with the interior of said combustion chamber;
- said primary flue having a diameter and being connected to said upper and lower ends of said tank;
- a fuel burner associated with said combustion chamber and operative to receive fuel and air from sources thereof and create therefrom hot combustion products flowable from said combustion chamber through said primary flue;
- and
- a tubular secondary flue disposed within said tank and having a diameter smaller than the diameter of said primary flue, said secondary flue being operative to receive and then discharge hot combustion products exiting said primary flue, said secondary flue further having an inlet portion coupled to said primary flue, and a vertically coiled section disposed beneath and extending downwardly away from said inlet portion and vertically extending only through about a bottom third to a bottom half of the interior of said tank.
4 more elements
Fuel-fired liquid heating apparatus comprising:
- a tank adapted to hold a quantity of liquid to be heated, said tank having upper and lower ends;
- a combustion chamber disposed beneath said lower end of said tank and being horizontally divided into a first portion and a second portion;
- a primary flue longitudinally extending vertically through the interior of said tank and communicating with said first portion of said combustion chamber;
- a fuel burner disposed within said first portion of said combustion chamber and operative to receive fuel and air from sources thereof and create therefrom hot combustion products that flow upwardly through said primary flue;
- and
- a secondary flue disposed within said tank and operative to receive hot combustion products exiting said primary flue, said secondary flue having an inlet portion coupled to said primary flue and extending from said inlet portion sequentially through the interior of said tank, said second portion of said combustion chamber, and then outwardly through an outer wall portion of said combustion chamber.
3 more elements
Fuel-fired liquid heating apparatus comprising:
- a tank adapted to hold a quantity of liquid to be heated, said tank having upper and lower ends;
- a combustion chamber disposed beneath said lower end of said tank and having a walled-off portion;
- a primary flue longitudinally extending vertically through the interior of said tank and communicating with said walled-off portion of said combustion chamber;
- a fuel burner disposed within said walled-off portion of said combustion chamber and operative to receive fuel and air from sources thereof and create therefrom hot combustion products that flow upwardly through said primary flue;
- and
- a secondary flue disposed within said tank and operative to receive hot combustion products exiting said primary flue, said secondary flue having an inlet portion coupled to said primary flue and extending from said inlet portion sequentially through the interior of said tank, said combustion chamber externally of said walled-off portion thereof, and then outwardly through an outer wall portion of said combustion chamber.
3 more elements
Dependencies are inferred from the claim text.