# US 10,480,821 B2 · Water heater

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- Number: US 10,480,821 B2
- Document ID: US10480821B2
- Status: Granted
- Kind: B2
- Application number: 15/580,712
- Filed: 2016-06-21
- Published: 2018-07-05
- Granted: 2019-11-19
- Earliest claimed: 2015-07-09
- Assignees: Rinnai Corporation
- Applicants: Rinnai Corporation
- Inventors: Takashi Ojiro
- Web page: https://patentgrep.com/patent/US10480821B2

## CPC

- F24H 8/006: {Means for removing condensate from the heater}
- F16L 55/00: Devices or appurtenances for use in, or in connection with, pipes or pipe systems (F16L1/00 - F16L53/00, F16L57/00, F16L59/00 take precedence; repairing or joining pipes on or under water F16L1/26; cleaning of pipes B08B9/02, e.g. removal of blockages B08B9/027; devices for preventing bursting of water pipes by freezing E03B7/10)
- F23D 14/825: {using valves}
- F23K 5/00: Feeding or distributing other fuel to combustion apparatus
- F23L 5/02: Arrangements of fans or blowers
- F23L 13/02: pivoted about a single axis but having not other movement (formed as linked slats each pivoted about an axis F23L13/08)
- F24H 1/145: {using fluid fuel}
- F24H 9/2042: {Preventing or detecting the return of combustion gases}
- F24H 15/345: Control of fans, e.g. on-off control (control of fans of heat pump units F24H15/375)
- F23D 2209/10: Flame flashback
- F24H 9/1836: using fluid fuel
- F24H 15/136: Defrosting or de-icing; Preventing freezing
- Y02B 30/00: Energy efficient heating, ventilation or air conditioning [HVAC]
- F24H: FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL (steam generation F22)
- F16L: PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F23D: BURNERS
- F23K: FEEDING FUEL TO COMBUSTION APPARATUS (fuel feeders specially adapted for fluidised bed combustion apparatus F23C10/22)
- F23L: SUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL ({air-supply arrangements for fluent fuels F23C;} firebridges with means for feeding air or steam F23M3/04; baffles or shields with air supply passages F23M9/04); VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS {(dampers and throat restrictors for open fire-places F24; air inlet valves for open fire fronts F24)}; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES
- Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS

## Abstract

A water heater includes a vessel (20) provided with a burner (3) having a downward combustion surface, a fan casing (10) accommodating a fan (10a) for supplying a mixture gas of primary combustion air and fuel gas to the burner, an annular packing connecting a first connection end surface at a downstream end of a first passage forming a downstream-side passage of the fan casing with a second connection end surface at an upstream end of a second passage forming an upstream-side passage of the vessel in airtight state, and a check valve (5) disposed near the upstream end in the second passage (2).

## Claims

### Claim 1

A water heater, comprising:
a vessel provided with a burner having a downward combustion surface;
a fan casing accommodating a fan for supplying a mixture gas of primary combustion air and fuel gas to the burner, the fan casing being in communication with the vessel;
an annular packing connecting a first connection end surface at a downstream end of a first passage forming a downstream-side passage of the fan casing with a second connection end surface at an upstream end of a second passage forming an upstream-side passage of the vessel in an airtight state; and
a check valve disposed near the upstream end in the second passage, wherein
the check valve includes a flange portion extending outward around an entire circumference of an upstream open end thereof,
at least one of the first connection end surface and the second connection end surface includes a first step portion configured to allow the annular packing to be fitted thereinto,
the second connection end surface includes a second step portion configured to allow the flange portion of the check valve to be fitted thereinto, and
the annular packing has an outer circumferential edge larger than a periphery of the flange portion of the check valve and an inner circumferential edge smaller than the periphery of the flange portion.

### Claim 2 (depends on 1)

The water heater according to claim 1, wherein the annular packing has an annular outer rib projecting along the entire outer circumferential edge in a thickness direction of the annular packing and an annular groove recessed along an inner base end portion of the outer rib in the thickness direction of the annular packing.

### Claim 3 (depends on 1)

The water heater according to claim 1, wherein the annular packing has an annular inner rib projecting along the entire inner circumferential edge in a thickness direction of the annular packing.

### Claim 4 (depends on 1)

The water heater according to claim 1, wherein at least one of an upstream end surface of the flange portion and a portion of the annular packing facing the flange portion has an annular ridge.

### Claim 5 (depends on 1)

The water heater according to claim 1, wherein the flange portion has a thickness substantially equal to a depth of the second step portion.

### Claim 6 (depends on 2)

The water heater according to claim 2, wherein the annular packing has an annular inner rib projecting along the entire inner circumferential edge in the thickness direction of the annular packing.

### Claim 7 (depends on 2)

The water heater according to claim 2, wherein at least one of an upstream end surface of the flange portion and a portion of the annular packing facing the flange portion has an annular ridge.

### Claim 8 (depends on 2)

The water heater according to claim 2, wherein the flange portion has a thickness substantially equal to a depth of the second step portion.

### Claim 9 (depends on 3)

The water heater according to claim 3, wherein at least one of an upstream end surface of the flange portion and a portion of the annular packing facing the flange portion has an annular ridge.

### Claim 10 (depends on 3)

The water heater according to claim 3, wherein the flange portion has a thickness substantially equal to a depth of the second step portion.