# US 11,906,159 B2 · Frustoconical combustion chamber for a fluid heating device and methods for making the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,906,159 B2 - Document ID: US11906159B2 - Status: Granted - Kind: B2 - Application number: 17/588,434 - Filed: 2022-01-31 - Published: 2022-05-12 - Granted: 2024-02-20 - Earliest claimed: 2020-04-27 - Assignees: Rheem Manufacturing Company - Applicants: Rheem Manufacturing Company - Inventors: Amin Monfared; Leonard E. Chambers; Miguel Mendoza; Arash Jafari; Babak Bagheri; Bruce Hotton - Web page: https://patentgrep.com/patent/US11906159B2 ## CPC - F23C 3/00: Combustion apparatus characterised by the shape of the combustion chamber - F24H 1/145: {using fluid fuel} - F24H 1/287: {with the fire tubes arranged in line with the combustion chamber} - F24H 9/1836: using fluid fuel - F23C: METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN {A CARRIER GAS OR} AIR (burners F23D) - F24H: FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL (steam generation F22) ## Abstract The disclosed technology includes a fluid heating device including a frustoconical combustion chamber and a heat exchanger that can include heating tubes. The combustion chamber can have a first end and a second end that is in fluid communication with the heating tubes. The surface area of the second end of the combustion chamber can be larger than the surface area of the first end of the combustion chamber. ## Claims ### Claim 1 A fluid heating device comprising: an outer shell having a fluid inlet and a fluid outlet, the outer shell defining a fluid heating volume for heating fluid; a heat exchanger including heating tubes that are each fluidly isolated from the fluid heating volume, the heat exchanger being concentrically disposed with respect to the outer shell such that a channel is formed between an inner surface of the outer shell and an outer surface of the heat exchanger; and a combustion chamber having a substantially frustoconical shape in fluid connection with the heating tubes of the heat exchanger, the combustion chamber including: a first end having a first surface area; a second end having a second surface area that is larger than the first surface area, the second end being in fluid connection with the heating tubes of the heat exchanger; and at least one angled sidewall including an angled portion that extends along a portion of a height of the combustion chamber, wherein the angled portion has an angle relative to the first end of from 90.5 degrees to 120 degrees, and wherein the fluid outlet is positioned in the outer shell at the second end of the combustion chamber. ### Claim 2 (depends on 1) The fluid heating device of claim 1, wherein the combustion chamber has at least one corner. ### Claim 3 (depends on 2) The fluid heating device of claim 2, wherein the combustion chamber includes a first angled sidewall and a second angled sidewall. ### Claim 4 (depends on 1) The fluid heating device of claim 1, wherein the combustion chamber includes a first angled sidewall and a second angled sidewall. ### Claim 5 (depends on 1) The fluid heating device of claim 1, wherein the second surface area is in the range of approximately 1.02 times and approximately 9 times larger than the first surface area. ### Claim 6 (depends on 1) The fluid heating device of claim 1, wherein the first end has a first diameter and the second end has a second diameter, the second diameter being in the range of approximately 1.02 times and approximately 3 times larger than the first diameter. ### Claim 7 (depends on 1) The fluid heating device of claim 1, wherein the outer shell has a diameter larger than a diameter of the heat exchanger. ### Claim 8 (depends on 7) Fluid heating device of claim 7, wherein the channel has a width in a range between approximately 0.25 inches and approximately 1.5 inches. ### Claim 9 (depends on 7) The fluid heating device of claim 7, wherein the diameter of the outer shell is in a range between approximately 1.05 times and approximately 3.5 times larger than a first diameter of the first end of the combustion chamber. ### Claim 10 (depends on 1) The fluid heating device of claim 1, wherein at least a portion of a sidewall of the combustion chamber is corrugated. ### Claim 11 (depends on 1) The fluid heating device of claim 1, wherein a flow of combustion gas through the combustion chamber substantially correlates to a shape of the combustion chamber. ### Claim 12 (depends on 1) The fluid heating device of claim 1, wherein the angled portion of the at least one angled sidewall has an angle relative to the first end of approximately 96 degrees. ### Claim 13 (depends on 1) The fluid heating device of claim 1, further comprising an igniter positioned within the combustion chamber proximal to the first end and configured to expel combustion gases towards the second end and towards the at least one angled sidewall such that the substantially frustoconical shape directs the flow of combustion gases to the heating tubes of the heating exchanger. ### Claim 14 (depends on 1) The fluid heating device of claim 1, wherein a gap is formed proximate the first end of the combustion chamber between an exterior surface of the combustion chamber and the inner surface of the outer shell. ### Claim 15 A method for manufacturing a fluid heating device, the method comprising: providing an outer shell including a fluid inlet and a fluid outlet; positioning a heat exchanger concentrically within the outer shell such that a channel is formed between an inner surface of the outer shell and an outer surface of the heat exchanger, the heat exchanger including an inlet tube sheet disposed proximate a first end of the heat exchanger, an outlet tube sheet disposed proximate a second end of the heat exchanger, and a plurality of heating tubes extending between the inlet tube sheet and the outlet tube sheet; providing a combustion chamber having a substantially frustoconical shape, a first end that has a first surface area, second end that has a second surface area larger than the first surface area, wherein the fluid outlet is positioned in the outer shell at the second end of the combustion chamber, and at least one angled sidewall including an angled portion that extends along a portion of a height of the combustion chamber, the angled portion having an angle relative to the first end of from 90.5 degrees to 120 degrees; attaching the combustion chamber to the heat exchanger such that the combustion chamber is in fluid communication with the plurality of heating tubes; and connecting a blower system to the first end of the combustion chamber, the blower system being configured to provide an air/fuel mixture to the combustion chamber. ### Claim 16 (depends on 15) The method of claim 15, wherein the heat exchanger is positioned in a substantially coaxial location with respect to the outer shell. ### Claim 17 (depends on 15) The method of claim 15, wherein an outer edge of the combustion chamber is substantially flush with an outer edge of a top surface of the heat exchanger. ### Claim 18 (depends on 15) The method of claim 15, wherein the channel has a width in a range between approximately 0.25 inches and approximately 1.5 inches. ### Claim 19 (depends on 15) The method of claim 15, wherein the angled portion of the at least one angled sidewall has an angle relative to the first end of approximately 96 degrees.