Heating device having a secondary safety circuit for a fuel line and method of operating the same
AssigneeAOS Holding Company
InventorsDennis R. Hughes, Hyungsik Lee
Life of this patent
Estimating the term…
Abstract
A secondary safety circuit for a gas-fired device and method of operating the circuit. The secondary safety circuit includes a low-voltage direct current power source, a valve, and at least one sensor. The valve can be positioned in a pilot burner gas line. The secondary safety circuit ensures the valve is closed upon detecting an unsafe condition with the sensor.
Claims14
A gas water heater comprising:
- a burner;
- a gas valve coupled to the burner;
- a pilot light being operable to produce a flame;
- a pilot safety circuit comprising a thermocouple thermally coupled to the pilot light and electrically coupled to the gas valve, the pilot safety circuit being configured to ensure the gas valve is closed in response to the flame extinguishing;
- and
- a secondary safety circuit comprising
- a low-voltage power source distinct from the thermocouple, and
- a safety detecting device distinct from and powered by the low-voltage power source, the safety detecting device configured to detect a safety condition different from the flame extinguishing detected by the pilot safety circuit, and to issue a signal in response to the safety condition,
- a second normally-open, magnetically-actuated gas valve coupled to the pilot light, the second normally-open, magnetically-actuated gas valve closing in response to receiving the signal from the safety detecting device.
A method of controlling a gas water heater including a pilot light, a pilot safety circuit, a main burner, a gas valve, and a secondary safety circuit, the secondary safety circuit being distinct from the pilot safety circuit, the secondary safety circuit having a low-voltage power source, a safety detecting device, and a second valve coupled to the pilot light, the method comprising:
- detecting a condition with the safety detecting device, the safety detecting device being distinct from and powered by the low-voltage power source;
- issuing a signal in response to the condition with the safety detecting device;
- applying a voltage from the low-voltage power source to the second valve in response to the signal;
- closing the second valve in response to applying the voltage, thereby ensuring a flame of the pilot is extinguished;
- detecting the extinguishing of the flame by the pilot safety circuit;
- and
- closing the gas valve by the pilot safety circuit when extinguishing of the flame is detected.
Dependencies are inferred from the claim text.