Forced draft water heater with an improved tank structure and a method for making water heaters

• US 5,179,914 A
• Filed: 10/30/1991
• Issued: 01/19/1993
• Est. Priority Date: 09/30/1991
• Status: Expired due to Fees

• Current Assignee: Sabh Water Heater Group, Inc.
• Original Assignee: MOR-FLO Industries, Inc.
• Inventors: Moore, Henry J. Jr., Deneau, Myron E., Gidanian, Bijan
• Primary Examiner(s): Favors, Edward G.
• Application Number:
  US07/784,887
• Time in Patent Office: 447 Days
• Field of Search: 122/13.1, 122/17, 122/18, 122/19, 122/14, 126/361, 29/890.051
• US Class Current: 122/19.2
• CPC Class Codes: F24H 1/182 Insulation
• CPC Class Codes: F24H 1/205 with furnace tubes
• CPC Class Codes: F24H 9/1836 using fluid fuel
• CPC Class Codes: Y10T 29/49385 Made from unitary workpiece, i.e., no assembly

Abstract

A fuel fired, high capacity, high efficiency water heater uses a cylindrical plastic tank. The strength of the plastic tank is maintained by keeping the side wall imperforate and providing all access to the interior through metallic top and bottom plates.

Claims

1. A water heater comprising:

a generally cylindrical, non-metallic tank having a large bottom opening having a bottom opening minimum diameter, a top opening and an imperforate generally cylindrical side wall;

a body of insulation substantially surrounding said tank;

a metallic bottom plate adapted to close said tank bottom opening having an upwardly facing inside and a downwardly facing outside;

a metallic combustion chamber wall enclosing a combustion chamber fixed to said bottom plate;

a cold water inlet tube passing through and fixed to said bottom plate;

a products of combustion outlet passing through and fixed to said bottom plate;

bottom fixing means fixing said bottom plate to said tank closing said bottom opening;

a burner disposed within said combustion chamber;

a circular opening in said bottom plate disposed beneath said burner;

means supplying air and fuel to said burner;

means fixing said air and fuel supplying means to said bottom plate; and

,

exhaust means communicating said combustion chamber to said products of combustion outlet.

2. The water heater of claim 1 wherein said bottom plate, said combustion chamber wall, said cold water inlet tube and said products of combustion outlet are stainless steel.

3. The water heater of claim 1 wherein said combustion chamber wall, said cold water inlet tube and said products of combustion outlet are welded to said bottom plate.

4. The water heater of claim 1 wherein said exhaust means comprises an exhaust gas exit tube having a combustion chamber end fixed to said combustion chamber, a helical segment of several turns having a helical segment maximum horizontal diameter and a tank exit portion passing through said bottom plate, said helical segment maximum horizontal diameter being smaller than said bottom opening minimum diameter.

5. The water heater of claim 4 further comprising a metallic top plate adapted to close said tank top opening having a hot water outlet therein.

6. The water heater of claim 5 wherein the highest extending element mounted on said bottom plate extends less high than a first horizontal plane in said tank and said lowest extending element mounted on said top plate extends less low than said first horizontal plane whereby said top plate mounted elements cannot contact said bottom plate mounted elements.

7. The water heater of claim 4 wherein said bottom fixing means comprises a bottom flange about said bottom opening integral with said tank, a plurality of bolt holes in said bottom flange, a plurality of bolt holes in said bottom plate and fasteners pressing through said bottom flange bolt holes and said bottom plate bolt holes.

8. The water heater of claim 1 wherein said bottom plate further comprises a recess around said circular opening, and said water heater further comprises a combustion chamber bottom wall, said combustion chamber bottom wall being retained in said recess and welded to said bottom plate about the periphery of said circular opening, said metallic combustion chamber wall being received in said recess and welded to said bottom plate about the periphery of said recess.

9. A water heater comprising:

a non-metallic tank having a large bottom opening and a top opening and an imperforate generally cylindrical sidewall;

a body of insulation substantially surrounding said tank;

a metallic bottom plate adapted to close said tank bottom opening having a combustion chamber access opening, a cold water inlet opening and a products of combustion outlet opening;

a metallic top plate having a hot water outlet opening;

a combustion chamber enclosure enclosing a combustion chamber within said tank fixed to said bottom plate;

an exhaust gas exit tube connecting said combustion chamber to said products of combustion outlet opening;

10. The water heater of claim 9 wherein said bottom plate, said top plate, said combustion chamber wall, said cold water inlet and said products of combustion outlet are stainless steel.

11. The water heater of claim 9 wherein said combustion chamber wall, said cold water inlet tube and said products of combustion outlet are welded to said bottom plate.

12. The water heater of claim 9 wherein said exhaust means comprises an exhaust gas exit tube having a combustion chamber end fixed to said combustion chamber, a helical segment of several turns having a helical segment maximum horizontal diameter and a tank exit portion passing through said bottom plate, said helical segment maximum horizontal diameter being smaller than said bottom opening minimum diameter.

13. The water heater of claim 9 wherein the highest extending element mounted on said bottom plate extends less high than a first horizontal plane in said tank and said lowest extending element mounted on said top plate extends less low than said first horizontal plane whereby said top plate mounted elements cannot contact said bottom plate mounted elements.

14. The water heater of claim 9 wherein said bottom fixing means comprises a bottom flange about said bottom opening integral with said tank, a plurality of bolt holes in said bottom flange, a plurality of bolt holes in said bottom plate and fasteners pressing through said bottom flange bolt holes and said bottom plate bolt holes.

15. A method of constructing a water heater comprising:

providing a generally cylindrical, non-metallic tank having a large bottom opening and an imperforate side wall;

providing a metallic bottom plate adapted to close said tank bottom opening, said bottom plate having a combustion chamber access opening, a cold water inlet opening and a products of combustion outlet opening;

welding a combustion chamber wall having a combustion chamber outlet surrounding a combustion chamber to said bottom plate such that said combustion chamber access opening communicates with said combustion chamber;

providing a products of combustion conduit communicating said combustion chamber outlet to said bottom plate products of combustion outlet opening;

providing a blower and air/fuel proportioner assembly to said bottom plate such that said blower and air/fuel proportioner assembly communicates with said combustion chamber access opening;

providing a base, an outer jacket bottom, an outer jacket side wall and an outer jacket top;

providing thermal insulation adapted to surrounding said tank;

assembling said tank, said bottom plate, said outer jacket bottom, said outer jacket side wall, said outer jacket top such that said tank bottom opening is closed and said insulation surrounds said tank.

16. The method of claim 15 wherein said insulation is precast foam insulation.

17. A method of constructing a water heater comprising:

providing a generally cylindrical non-metallic tank having a large bottom opening, a top opening and an imperforate, generally cylindrical side wall;

providing a metallic bottom plate adapted to close said tank bottom opening, said plate having a combustion chamber access opening, a cold water inlet opening and a products of combustion outlet opening;

welding a combustion chamber wall having a combustion chamber outlet surrounding a combustion chamber to said bottom plate such that said combustion chamber access opening communicates with said combustion chamber.

providing a products of combustion conduit communicating said combustion chamber outlet to said bottom plate products of combustion outlet opening;

providing a metallic top plate adapted to close said tank top opening, said top plate having a hot water outlet opening;

providing a blower and air/fuel proportioner assembly adapted to be mounted to said bottom plate such that said blower and air/fuel proportion assembly communicates with said combustion chamber access opening;

providing a base;

providing an outer jacket;

providing a body of thermal insulation adapted to surround said tank; and

,

assembly said tank said body of insulation, said bottom plate, said top plate, said outer jacket;

said blower and air/fuel proportion assembly, such that said tank is water tightly sealed.

18. The method of claim 17 wherein said non-metallic tank is provided with a flange surrounding said bottom opening and a flange surrounding said top opening, said bottom plate is bolted to said flange surrounding said bottom opening and said top plate is bolted to said flange surrounding said top opening.