Safety apparatus for combustion device
AssigneesRinnai Corporation, Tokyo Gas Co., Ltd.
InventorsTakashi Ueki, Yoshihiro Ishikawa
Life of this patent
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Abstract
A CO sensor is mounted on the heat exchanger of a gas water heater (or other combustion unit) and is connected in circuit with a detecting unit mounted separately from the heater. The detecting unit generates a control voltage in opposition to a reference voltage on a solenoid. The solenoid controls a valve in a fuel supply passage to a burner (or burners) in the heater, thereby shutting off the burners when the CO concentration reaches a predetermined value. A timing circuit may be added to cut off the burners whenever a lesser CO concentration continues for a predetermined time period.
Claims13
In a combustion unit having at least one burner therein, a safety valve in a fuel supply passage to the burner, a solenoid means for controlling the valve, and means for providing a reference voltage to the solenoid means, the improvement which comprises a detecting means including a sensor means operatively positioned and arranged with respect to the combustion unit for sensing concentration of CO in space influenced by exhaust gas therefrom, said detecting means also including a power source and a switching means, the sensor means being connected between the power source and the switching means;
- and wherein in the event of a potentially hazardous situation, the detecting means generates a voltage of opposite polarity to the reference voltage, and wherein at a predetermined difference between the reference voltage and the generated voltage from the detecting means, the solenoid means is actuated to close the valve in the fuel supply passage, thereby turning off the burner.
In a gas water heater, the combination of at least one burner, a heat exchanger, a body between the burner and the heat exchanger, a safety valve in a fuel supply passage to the burner, a solenoid means for controlling the valve, means including a thermocouple mounted in the heater in juxtaposition to the burner for providing a reference voltage, a pair of external terminals on the heater, a detecting unit connected to the terminals and generating a voltage of opposite polarity to the reference voltage, the detecting unit including a power source, a switching element and a sensor means connected therebetween, and the sensor means comprising a CO sensor whose resistance changes in accordance with the gas concentration, whereby at a predetermined difference between the reference voltage and the voltage generated by the detecting unit, the solenoid means is actuated to close the valve, thereby turning off the burner.
In a combustion unit, the combination of at least one burner, a fuel supply passage means to the burner, a valve in the fuel supply passage means, means for controlling the valve, and detecting means including CO sensing means responsive to both a predetermined CO concentration and to a predetermined time period of a CO concentration to actuate the valve controlling means, thereby closing the valve and turning off the burner, wherein the detecting means also includes a power source and a switching element, and wherein the sensing means is connected between the power source and the switching element.
Dependencies are inferred from the claim text.