Patent Application
20120090600
Exemplary embodiments pertain to the art of furnace systems and, more particularly, to an inducer fan assembly for a furnace system.
Gas furnace systems burn a combustible gas to generate heat. In operation, air is drawn from a comfort region into the furnace. The air from the comfort region is passed through a heat exchanger, heated by the burning combustible gas, and delivered back into the comfort region. A typical heat exchanger includes a series of passages each of which is heated by the burning combustible gas. Products of combustion of the burning combustible gas or flue gas are typically drawn through the passages of the heat exchanger, into a collector box and then discharged to ambient via a chimney or flue pipe through the action of an inducer fan assembly. A typical inducer fan assembly includes a housing, an electric motor, and a centrifugal fan rotor driven by the motor shaft. The housing includes a central inlet, a volute collector region and an outlet port that extends from the collector region.
Disclosed is an inducer fan assembly including a flow collector piece including a motor support surface, a substantially toroidal collector, and a discharge region extending substantially tangentially from the collector. The collector forms a central recessed zone in the housing. A fan rotor is rotatably mounted relative to the motor support surface. The fan rotor includes a hub surface, a central region, and an outer circumferential edge. The fan rotor further includes a plurality of blades that extend from the hub surface. The plurality of blades extend from a leading edge at the central region across the hub surface to a trailing edge that extends beyond the outer circumferential edge. The plurality of blades include a first height at the central region and a second height at the circumferential edge. The second height is less than the first height. The first and second heights define a blade tip revolved contour. The collector is arranged radially outward from and axially off-set from the hub surface of the fan rotor. An inlet casing piece is mounted to the flow collector piece. The inlet casing piece includes a central opening that registers with the central region, and an inlet casing contour that is substantially similar to the blade tip revolved contour of the fan rotor.
Also disclosed is a gas furnace system including a heat exchanger, a collector box connected to the heat exchanger, and an inducer fan assembly fluidly connected to the collector box. The inducer fan assembly includes a flow collector piece including a motor support surface, a substantially toroidal collector, and a discharge region extending substantially tangentially from the collector. The collector forms a central recessed zone in the housing. A fan rotor is rotatably mounted relative to the motor support surface. The fan rotor includes a hub surface, a central region, and an outer circumferential edge. The fan rotor further includes a plurality of blades that extend from the hub surface. The plurality of blades extend from a leading edge at the central region across the hub surface to a trailing edge that extends beyond the outer circumferential edge. The plurality of blades include a first height at the central region and a second height at the circumferential edge. The second height is less than the first height. The first and second heights define a blade tip revolved contour. The collector is arranged radially outward from and axially off-set from the hub surface of the fan rotor. An inlet casing piece is mounted to the flow collector piece. The inlet casing piece includes a central opening that registers with the central region, and an inlet casing contour that is substantially similar to the blade tip revolved contour of the fan rotor.
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
With reference to
Gas furnace system 2 is also shown to include a burner assembly 30 mounted to component support wall 18. Burner assembly 30 includes a burner box 32 and a gas valve 34. Burner assembly 30 combusts a fuel, in the form of gas to generate heat used to condition a comfort zone such as living spaces, work spaces and the like. Products of combustion or exhaust gases generated by the burning of the fuel are expelled to ambient. In the Exemplary embodiment shown, burner assembly 30 is operatively connected to a primary heat exchanger 40 arranged within heat exchange portion 13. Primary heat exchanger 40 is operatively coupled to a condensing heat exchanger 42. Condensing heat exchanger 42 includes a plurality of heat exchange members 46. With this arrangement, a blower motor assembly 50 arranged within blower portion 15 draws in air from a space to be heated. The air is guided over primary heat exchanger 40, and condensing heat exchanger 42. The air is heated and then re-introduced into the space.
During operation of gas furnace system 2, moisture from the products of combustion condenses in condensing heat exchanger 42. This moisture is collected in a condensate collector system 60 and passed on to an external drain (not shown) Gas furnace system 2 further includes an inducer fan assembly 70 mounted to condensate collector system 60. Inducer fan assembly 70 creates an air flow that draws products of combustion from burner box 32, and through condensate collector system 60. Inducer fan assembly 70 then directs the products of combustion through a flue vent 73. Inducer fan assembly 70 produces a pressure rise and flow rate to achieve a desired combustion performance while overcoming flow losses within gas furnace system 2.
As best shown in
Inlet casing piece 82 includes an end wall 110 having an inlet opening 113 and a circular rim portion 117. As will be discussed more fully below, end wall 110 includes an inlet casing contour that closely conforms to, or follows a shape of fan rotor 85. More specifically, end wall 110 includes an inlet casing contour that follows a blade revolved profile of fan rotor 85. Inlet casing piece 82 is further shown to include a discharge zone 121 that extends substantially tangentially from end wall 110 and a plurality of mounting elements, one of which is indicated at 125, that extend about circular rim portion 117. Discharge zone 121 is configured to mate with air guide zone 104 on flow collector piece 81 to form a discharge pipe (not separately labeled) Mounting elements 125 register with corresponding ones of mounting members 100 to join flow collector piece 81 with inlet casing piece 82.
As best shown in
In the exemplary embodiment shown, blade 133 includes a first end or leading edge 147 that extends to a second end or trailing edge 148 through an intermediate portion 150, and a tip edge 151. Intermediate portion 150 includes a pressure side 152 and a suction side 153. Intermediate portion 150 is backward curved relative to a rotational direction of fan rotor 85. Leading edge 147 is formed having a first height, and trailing edge 148 is formed having a second height that is less than the first height. The first and second heights combine to define blade tip revolved contour 144.
In accordance with one aspect of the exemplary embodiment, trailing edge end 148 extends beyond outer circumferential edge 131 to form a protrusion 154. Blade 133 is also shown to be joined to hub 127 thought a fillet region 155. Fan rotor 85 is also shown to include a plurality of ribs, one of which is shown at 160, formed on an opposing surface 165. Fillet region 155 and ribs 160 provide structural stability for fan rotor 85. Finally, fan rotor 85 is shown to include an insert (
At this point it should be understood that inducer fan assembly 70 has a compact form factor without detracting from an overall operational efficiency. That is, by forming fan rotor 85 without an integral rotating shroud, inducer fan assembly has a lower profile than existing furnace inducer fans. The lower profile leads to greater flexibility in plumbing various outlet options resulting in more compact furnace configurations. The term “axially off-set” should be understood to mean off-set relative to the hub surface of the fan rotor in a direction away from the inlet casing along an axis of rotation of motor 86. Moreover, the axially off-set collector manages rotor outlet flow and formed a recess zone for motor mounting. Furthermore, arranging the collector outlet port axially off-set from the fan rotor leads to a more quiet operation of inducer fan assembly 70. More specifically, the axial off-set reduces unsteady interaction between the rotor blades and any discharge flow passing to the collector outlet port. Reducing the unsteady interaction has been shown to lead to lower sound levels during operation.
While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims.
This is a Non-Provisional Application of Provisional Application Ser. No. 61/393,473, filed Oct. 15, 2010.
| Number | Date | Country | |
|---|---|---|---|
| 61393473 | Oct 2010 | US |
