Gas delivery system with pre-mix blower
A gas delivery system for an appliance, such as a water heater, including a gas control valve and a blower housing assembly which are mounted to the water heater proximate one another. The blower housing assembly includes a motor for driving an impeller within the blower housing, and an outlet of the blower housing is connected to the gas burner assembly of the water heater. A gas supply conduit extends from the control valve into the blower housing, and the outlet of the gas supply conduit is disposed within the blower housing interior near the blower housing inlet and the central portion of the impeller. In operation, rotation of the impeller draws a flow of air through the blower housing. Concurrently, gas is supplied through the gas supply conduit to the interior of the blower housing near the impeller, and the gas is mixed with the flow of air to form an air/gas mixture which is supplied through the outlet of the blower housing to the gas burner for combustion. In this manner, the gas is pre-mixed with air within the blower housing before being supplied to the burner assembly, and wherein combustion of the air/gas mixture results in a cleaner combustion with reduced nitrous oxide emissions.
1 . A gas supply assembly for supplying an air/gas mixture to the burner assembly of a water heater, comprising:
a blower housing assembly, comprising:
a blower housing having an inlet, and an outlet in fluid communication with the gas burner assembly;
a motor having a rotatable output shaft; and
an impeller coupled to said output shaft and disposed within said blower housing; and
a gas supply conduit fluidly communicating a source of gas to said blower housing, whereby rotation of said impeller draws air into said blower housing through said inlet, and gas supplied through said gas supply conduit is mixed with the air within said blower housing to form an air/gas mixture which is supplied to the gas burner assembly through said blower housing outlet.
2 . The gas supply assembly of claim 1 , wherein said gas supply conduit includes an outlet end disposed adjacent said inlet of said blower housing.
3 . The gas supply assembly of claim 1 , wherein said gas supply conduit includes an outlet end aligned substantially 90° with respect to a direction of air flow into said blower housing inlet.
4 . The gas supply assembly of claim 1 , wherein said blower housing includes a bore, at least a portion of said gas supply conduit received within said bore.
5 . The gas supply assembly of claim 1 , further comprising a control valve in fluid communication with the gas source, said control valve selectively controlling gas flow from the gas source through said gas supply conduit.
6 . The gas supply assembly of claim 5 , wherein said gas supply conduit comprises:
an inlet end connected to said control valve; and
an outlet end connected to said blower housing.
7 . The gas supply assembly of claim 6 , wherein at least one of said inlet and said outlet ends of said gas supply conduit is connected to said control valve and said blower housing via a compression fitting.
8 . A gas supply assembly for supplying an air/gas mixture to the burner assembly of a water heater, comprising:
a blower housing assembly, comprising:
a blower housing having an inlet, and an outlet in fluid communication with the gas burner assembly;
a motor having a rotatable output shaft; and
an impeller coupled to said output shaft and disposed within said blower housing; and
a control valve fluidly communicating a source of gas to said blower housing, whereby rotation of said impeller draws air into said blower housing through said inlet, and gas supplied through said control valve is mixed with the air within said blower housing to form an air/gas mixture which is supplied to the gas burner assembly through said blower housing outlet.
9 . The gas supply assembly of claim 8 , further comprising a gas supply conduit connecting said control valve and said blower housing.
10 . The gas supply assembly of claim 9 , wherein said gas supply conduit includes an outlet end disposed adjacent said inlet of said blower housing.
11 . The gas supply assembly of claim 9 , wherein said gas supply conduit includes an outlet end aligned substantially 90° with respect to a direction of air flow into said blower housing inlet.
12 . The gas supply assembly of claim 9 , wherein at least one of an inlet and an outlet end of said gas supply conduit is connected to said control valve and said blower housing via a compression fitting.
13 . A method of operating a gas supply assembly for a water heater, comprising the steps of:
rotating an impeller within a blower housing to induce an air flow through the blower housing;
supplying gas from a gas source into the blower housing;
mixing the gas with the air flow within the blower housing to form an air/gas mixture; and
supplying the air/gas mixture to a burner assembly of the water heater.
14 . The method of claim 13 , wherein said supplying step further comprises supplying gas from a gas source into the blower housing through a gas supply conduit fluidly connecting the gas source to the blower housing.
15 . The method of claim 13 , wherein said supplying step further comprises supplying gas from a gas source into the blower housing through a control valve.
16 . The method of claim 13 , wherein said supplying step further comprises supplying gas from a gas source into the blower housing at a location adjacent an inlet of the blower housing.