Fuel-fired heating appliance with dilution air/flammable vapor bypass tube and elevated combustion air inlet

• US 6,622,661 B1
• Filed: 01/16/2003
• Issued: 09/23/2003
• Est. Priority Date: 01/16/2003
• Status: Active Grant

• Current Assignee: Rheem Manufacturing Company (Paloma Co., Ltd.)
• Original Assignee: The Water Heater Industry Joint Research And Development Consortium
• Inventors: Hotton, Bruce A.
• Primary Examiner(s): Lu, Jiping
• Application Number:
  US10/345,592
• Time in Patent Office: 250 Days
• Field of Search: 122/13.01, 122/17.1, 122/17.2, 122/18.3, 122/18.31, 122/504
• US Class Current: 122/13.01
• CPC Class Codes: F23L 17/00 Inducing draught; Tops for chimneys or ventilating shafts; Terminals for flues
• CPC Class Codes: F23M 2900/11021 Means for avoiding accidental fires in rooms where the combustion device is located
• CPC Class Codes: F24H 1/205 with furnace tubes
• CPC Class Codes: F24H 9/2035 using fluid fuel

Abstract

A fuel-fired heating apparatus, representatively a forced draft or natural draft gas-fired water heater having a combustion chamber, is provided with a flammable vapor control system that functions, during firing of the apparatus, to substantially prevent entry into and combustion within the combustion chamber of extraneous flammable vapors externally adjacent the bottom of the apparatus, without detecting the extraneous flammable vapors or terminating firing of the apparatus. The flammable vapor control system includes a dilution air flow passage connected to a discharge portion of the apparatus vent structure and having an inlet externally adjacent a bottom portion of the apparatus and operative to draw dilution air and extraneous flammable vapors into the vent structure discharge portion, and a combustion air flow passage having an inlet disposed adjacent the upper end of the apparatus, and an outlet communicated with the interior of the combustion chamber.

Claims

1. Fuel-fired heating apparatus having top and bottom portions and comprising:

a combustion chamber;

a burner structure operative to create hot combustion products within said combustion chamber;

a vent structure having an inlet portion communicated with said combustion chamber, and a discharge portion disposed adjacent said top portion of said heating apparatus, said vent structure being operative, during firing of said heating apparatus, to create a draft that draws the created hot combustion products through said vent structure toward said discharge portion thereof; and

a flammable vapor control system for substantially preventing entry into and combustion within said combustion chamber of extraneous flammable vapors externally adjacent said bottom portion of said heating apparatus, without detecting the extraneous flammable vapors or terminating firing of said heating apparatus, said flammable vapor control system including;

a dilution air flow passage coupled to said discharge portion of said vent structure, isolated from direct communication with said combustion chamber, and having an inlet portion positioned externally adjacent said bottom portion of said heating apparatus, said dilution air flow passage functioning, during firing of said heating apparatus, to draw dilution air and said extraneous flammable vapors into said discharge portion of said vent structure for discharge therefrom, and

a combustion air flow passage having an inlet disposed in an elevated relationship with said bottom portion of said heating apparatus, and an outlet communicated with said combustion chamber.

2. The fuel-fired heating apparatus of claim 1 wherein:

said outlet of said combustion air flow passage is directly connected to said combustion chamber.

3. The fuel-fired heating apparatus of claim 2 wherein:

substantially all of the combustion air supplied to said combustion chamber interiorly traverses said combustion air flow passage.

4. The fuel-fired heating apparatus of claim 1 wherein:

said heating apparatus is a fuel-fired water heater.

5. The fuel-fired heating apparatus of claim 1 wherein:

said heating apparatus is a gas-fired water heater.

6. The fuel-fired heating apparatus of claim 1 wherein:

said heating apparatus is a forced draft heating appliance,

said discharge portion of said vent structure includes a draft inducer fan having an inlet portion, and

said dilution air flow passage is coupled to said inlet portion of said draft inducer fan.

7. The fuel-fired heating apparatus of claim 6 wherein:

said dilution air flow passage is defined by an external conduit structure.

8. The fuel-fired heating apparatus of claim 1 wherein:

said heating apparatus is a natural draft heating appliance.

9. The fuel-fired heating apparatus of claim 8 wherein:

said dilution air flow passage is defined by an external conduit structure.

10. The fuel-fired heating apparatus of claim 1 wherein:

said inlet of said combustion air flow passage is disposed adjacent said top portion of said fuel-fired heating apparatus.

11. The fuel-fired heating apparatus of claim 1 wherein:

said combustion chamber has a substantially imperforate bottom wall.

12. The fuel-fired heating apparatus of claim 1 wherein:

said combustion chamber is enclosed within and bounded by a wall structure substantially devoid of flame quenching openings.

13. Fuel-fired heating apparatus a bottom portion and comprising:

a combustion chamber disposed at said bottom portion of said heating apparatus;

a burner structure operative to create hot combustion products within said combustion chamber;

a vent structure operative having an inlet portion communicated with said combustion chamber, and a discharge portion, said vent structure being operative, during firing of said heating apparatus, to create a draft that draws the created hot combustion products through said vent structure toward said discharge portion thereof; and

a flammable vapor control system for substantially preventing entry into and combustion within said combustion chamber of extraneous flammable vapors externally adjacent said bottom portion of said heating apparatus, without detecting the extraneous flammable vapors or terminating firing of said heating apparatus, said flammable vapor control system including;

a dilution air flow passage coupled to said discharge portion of said vent structure, isolated from direct communication with said combustion chamber, and having an inlet portion positioned externally adjacent said bottom portion of said heating apparatus, said dilution air flow passage functioning, during firing of said heating apparatus, to draw dilution air and said extraneous flammable vapors into said discharge portion of said vent structure for discharge therefrom, and

a combustion air flow passage having an inlet for receiving ambient combustion air from adjacent said heating apparatus, and an outlet communicated with said combustion chamber.

14. The fuel-fired heating apparatus of claim 13 wherein:

said outlet of said combustion air flow passage is directly connected to said combustion chamber.

15. The fuel-fired heating apparatus of claim 14 wherein:

substantially all of the combustion air supplied to said combustion chamber interiorly traverses said combustion air flow passage.

16. The fuel-fired heating apparatus of claim 13 wherein:

said heating apparatus is a fuel-fired water heater.

17. The fuel-fired heating apparatus of claim 13 wherein:

said heating apparatus is a gas-fired water heater.

18. The fuel-fired heating apparatus of claim 13 wherein:

said heating apparatus is a forced draft heating appliance,

said discharge portion of said vent structure includes a draft inducer fan having an inlet portion, and

said dilution air flow passage is coupled to said inlet portion of said draft inducer fan.

19. The fuel-fired heating apparatus of claim 18 wherein:

said dilution air flow passage is defined by an external conduit structure.

20. The fuel-fired heating apparatus of claim 13 wherein:

said heating apparatus is a natural draft heating appliance.

21. The fuel-fired heating apparatus of claim 20 wherein:

said dilution air flow passage is defined by an external conduit structure.

22. The fuel-fired heating apparatus of claim 13 wherein:

said combustion chamber has a substantially imperforate bottom wall.

23. The fuel-fired heating apparatus of claim 13 wherein:

said combustion chamber is enclosed within and bounded by a wall structure substantially devoid of flame quenching openings.

24. A method of operating a fuel-fired heating apparatus having a combustion chamber disposed at a bottom portion thereof, a burner structure operative to create hot combustion products within said combustion chamber, and a vent structure having an inlet portion communicated with said combustion chamber, and a discharge portion, said vent structure being operative, during firing of said heating apparatus, to create a draft that draws the created hot combustion products through said vent structure toward said discharge portion thereof, for discharge therefrom, said method comprising the step of:

substantially preventing entry into and combustion within said combustion chamber, during firing of said heating apparatus, of extraneous flammable vapors externally adjacent said bottom portion of said heating apparatus, without detecting the extraneous flammable vapors or terminating firing of said heating apparatus, said substantially preventing step including the steps of;

drawing dilution air and said extraneous flammable vapors into said discharge portion of said vent structure from a location externally adjacent said bottom portion of said heating appliance, during firing thereof, into said discharge portion of said vent structure via a dilution air flow path isolated from direct communication with said combustion chamber, and

flowing ambient combustion air into said combustion chamber, from adjacent said heating apparatus, via a combustion air flow passage.

25. The method of claim 24 wherein:

said flowing step is performed using a combustion air flow passage having an inlet portion elevated relative to said bottom portion of said heating apparatus.

26. The method of claim 24 wherein:

said heating apparatus has a top portion, and

said flowing step is performed using a combustion air flow passage having an inlet portion disposed adjacent said top portion of said heating apparatus.

27. The method of claim 24 wherein:

said combustion air flow passage is defined by a conduit structure having an outlet, and

said flowing step includes the step of directly connecting said outlet to said combustion chamber.

28. The method of claim 27 wherein:

said flowing step is performed in a manner such that all of the combustion air supplied to said combustion chamber interiorly traverses said conduit structure.

29. The method of claim 24 wherein:

said heating apparatus is a forced draft heating appliance,

said discharge portion of said vent structure includes a draft inducer fan having an inlet portion, and

said drawing step is performed by drawing dilution air and said extraneous flammable vapors into said inlet portion of said draft inducer fan.

30. The method of claim 29 wherein:

said drawing step is performed using an external conduit structure.

31. The method of claim 24 wherein:

said heating apparatus is a natural draft heating appliance, and

said drawing step is performed using a conduit structure coupled to said discharge portion of said vent structure.

32. The method of claim 24 further comprising the step of:

providing said combustion chamber with a substantially imperforate bottom wall.

33. The method of claim 24 further comprising the step of:

bounding said combustion chamber with a wall structure substantially devoid of flame quenching openings.