ABSORPTION GAS ARRESTOR SYSTEM

• US 20080198524A1
• Filed: 02/16/2007
• Published: 08/21/2008
• Est. Priority Date: 02/16/2007
• Status: Abandoned Application

• Current Assignee: Dometic LLC
• Original Assignee: Dometic LLC
• Inventors: McCONNELL, PATRICK N., KARLSSON, ARNE, BUC, ELIZABETH C., LINDHAGEN, CARL H., REITE, FREDRIK
• Application Number:
  US11/675,996
• Publication Number:
  US 20080198524A1
• Time in Patent Office: Days
• US Class Current: 361/91.2
• CPC Class Codes: F23D 14/82 Preventing flashback or blowback
• CPC Class Codes: F23M 11/00 Safety arrangements
• CPC Class Codes: G01N 27/122 Circuits particularly adapted therefor, e.g. linearising circuits
• CPC Class Codes: G01N 33/0063 using a threshold to release an alarm or displaying means

Abstract

The subject application relates to a gas arrestor system(s) and/or methodology that facilitate sensing and shutting down a gas-burning appliance via a circuit that can perform both functions. In particular, the system and method can detect specific gases and at specific concentration levels by way of a sensory-power circuit. The circuit performs vapor detection and provides power to various ignition-related portions of the appliance. When gas or gas vapors are detected in the ambient air of the circuit and satisfy a threshold for that particular type of vapor, the circuit is shorted which results in a power loss to at least the ignition-related portions of the appliance. As a result, undesirable ignition of such vapors is mitigated.

Claims

1. A gas-arrestor system that facilitates termination of an ignitable portion of a gas burning device comprising:

at least two sensing resistors arranged in parallel within a power circuit, wherein the at least two sensing resistors are heated and adsorb oxygen on their surfaces to yield a build up of resistance and an isolation barrier between the resistors during normal operation of the gas burning device, and wherein the at least two sensing resistors detect at least one kind of gas at a specific concentration level by way of their voltage output; and

a decision component that measures the voltage output from the at least two sensing resistors to determine whether the voltage output correlates to a calibrated level below a lower explosion limit of at least one specific gas at a specific concentration,

characterized in that when the voltage output indicates the presence of at least one specified gas at a prescribed concentration, the at least two sensing resistors are shorted, thereby terminating power from the power circuit.

2. The system of claim 1, wherein each of the at least two sensing resistors comprise a thin layer of tin dioxide.

3. The system of claim 1, wherein the at least two resistors are exposed to ambient air and output voltage based on content of the ambient air.

4. The system of claim 1, wherein the decision component comprises a non-volatile memory that memorizes an occurrence of a sensing resistor-based power loss and prohibits a restart of at least a portion of the gas burning device before a service reset is performed on the device.

5. The system of claim 1, wherein the power circuit provides power to at least one portion of the gas burning device such that when power from the power circuit is terminated, the at least one portion no longer presents a fire hazard.

6. The system of claim 1, wherein the decision component signals a relay to open the power circuit in ambient air above the concentration level for which the sensing resistors are calibrated.

7. The system of claim 1, wherein the decision component signals activation of a fan to vent air surrounding the gas arrestor system when one or more gases are present at a concentration level that is approaching a shutdown threshold level.

8. The system of claim 1, wherein the at least two sensing resistors are calibrated to detect one or more kinds of gases at prescribed concentration levels by way of their voltage output such that a measured voltage output that is outside of a desired range indicates that a particular gas is present at a concentration level sufficient to alter the voltage output of the resistors.

9. The system of claim 1, further comprising a notification component that alerts a user when power from the power circuit is terminated.

10. The system of claim 9, wherein the notification component comprises at least one of an audible alarm and a visual indicator.

11. The system of claim 9, wherein the notification component is connected to a communication system that sends at least one of a voice or text message to alert the user when the power is terminated.

12. The system of claim 1, wherein the gas burning device is an absorption refrigerant appliance.

13. The system of claim 1, wherein the at least one kind of gas comprises at least one of ammonia, carbon monoxide, benzene, toluene, LP gas, and other flammable vapors comprising vapors from paint and solvents.

14. The system of claim 1, wherein the power circuit provides power to at least one of an ignition source and a fuel supply source.

15. The system of claim 1, wherein the sensing resistors are calibrated on a gas-by-gas basis and according to designated concentration levels for each gas so that the power circuit operates in the presence of some gases but not in the presence of others.

16. A gas-arresting method to mitigate undesirable ignition of gas vapor in a gas burning device comprising:

arranging two sensing resistors in parallel in a power circuit, the power circuit providing power to at least a portion of the gas burning device;

measuring a voltage output from the two sensing resistors; and

shorting the two sensing resistors when the voltage output indicates that a specified gas is present in ambient air at a specified concentration which results in a termination of power from the power circuit, thereby mitigating a potential fire hazard.

17. The method of claim 16, further comprising venting the gas burning device to further mitigate the potential fire hazard upon determining that the voltage output indicates that a specified gas is present at a specified concentration.

18. The method of claim 16, further comprising prohibiting a restart of at least a portion of the gas-burning device following a sensing resistor-based power loss before a service reset is performed on the device.

19. The method of claim 16, further comprising calibrating each of the two sensing resistors to operate and output a desired voltage when designated gas vapors are present in the ambient air in order to facilitate complete operation of the power circuit in the presence of acceptable gas vapors.