# US 4,398,882 A · Combustion safety apparatus

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- Number: US 4,398,882 A
- Document ID: US4398882A
- Status: Granted
- Kind: A
- Application number: 06/181,226
- Filed: 1980-08-25
- Granted: 1983-08-16
- Earliest claimed: 1979-09-01
- Assignees: Rinnai Corporation
- Inventors: Toshifumi Yamana
- Web page: https://patentgrep.com/patent/US4398882A

## CPC

- F23N 5/006: {the detector being sensitive to oxygen}
- F23N: REGULATING OR CONTROLLING COMBUSTION (control devices specially adapted for combustion apparatus in which combustion takes place in a fluidised bed of fuel or other particles F23C10/28; condition responsive controls for regulating combustion in domestic stoves with open fires for solid fuel F24B1/187)

## Abstract

There is provided a combustion safety apparatus where the main burner has a combustion detecting element such as an oxygen concentration cell element, and the element is arranged so that one electrode thereof is always heated by a flame of a standing burner and into an oxygen lack condition while the other electrode is heated by the main burner. When the main burner is in its complete combustion condition, there is a difference in oxygen concentration between the two electrodes and thereby there is generated an output at the element. On the other hand, when the main burner is in its incomplete combustion condition, the difference in oxygen concentration therebetween is decreased and thereby the output is lowered. In addition there is provided a safety device such as a gas safety valve or the like. The same is arranged to be controlled in operation by the output directly or indirectly; the element is formed into a long plate disposed to extend along nearly at a right angle to the direction of the flame of the standing burner.

## Claims

### Claim 1

A combustion safety apparatus of the type having a main burner in front thereof, with a combustion detecting element such as an oxygen concentration cell element or the like, the element having a first and second electrode, the first electrode thereof is always heated by a flame of a standing burner and is brought into lack of oxygen condition while the second electrode thereof is heated by the main burner, so that when the main burner is in its complete combustion condition, a difference in oxygen concentration between the two electrodes is formed to generate an output at the element; the main burner in its incomplete combustion condition has a decrease in oxygen concentration difference between the two electrodes and thereby the output at the element is lowered, and a safety device such as a gas safety valve or the like, arranged to be controlled in operation by the output of the element whereby: the element is formed into a long plate having a longitudinal axis, said plate being positioned such that said axis is disposed to extend nearly at a right angle to a center axis of the flame of the standing burner, said center axis being the longitudinal axis of the flame.

### Claim 2 (depends on 1)

A combustion safety apparatus as claimed in claim 1, wherein: the element is an oxygen concentration cell element comprising an element main body of zirconia and porous electrodes of platinum on both surface of the element main body.

### Claim 3 (depends on 1)

A combustion safety apparatus as claimed in claim 1, wherein: the center axis of the flame of the standing burner extends substantially vertically and inclines to a small degree towards the element and the longitudinal axis of the element extends horizontally.

### Claim 4 (depends on 1)

A combustion safety apparatus as claimed in claim 1, wherein: the standing burner is a standing pilot burner.