Variable Flow Gas Valve and Method for Controlling Same

• US 20100140520A1
• Filed: 12/08/2008
• Published: 06/10/2010
• Est. Priority Date: 12/08/2008
• Status: Active Grant

• Current Assignee: Robertshaw Controls Company (Schneider Electric SE)
• Original Assignee: Robertshaw Controls Company (Schneider Electric SE)
• Inventors: Millius, Michael J.
• Granted Patent: US 10,100,938 B2
• Time in Patent Office: Days
• US Class Current: 251/129.150
• CPC Class Codes: F16K 3/32 Means for additional adjustment of the rate of flow
• CPC Class Codes: F16K 3/34 Arrangements for modifying the way in which the rate of flow varies during the actuation of the valve
• CPC Class Codes: F16K 31/0675 Electromagnet aspects, e.g. electric supply therefor
• CPC Class Codes: Y10T 137/0318 Processes

Abstract

A gas control valve and method of controlling a gas control valve to provide infinite adjustability is provided. The gas control valve defines a fluid flow path. A flow adjustment arrangement within the fluid flow path has a plurality of discrete open configurations. Each discrete open configuration establishes a different flow rate through the fluid flow path. A controller operatively cyclically alternates the flow adjustment arrangement between different ones of the discrete configurations to provide an average flow rate through the fluid flow path that is between the flow rates permitted by the different ones of the discrete open configurations. The controller establishes residence times at the various ones of the discrete open configurations such that the resultant flow rate is the desired flow rate.

Claims

1. A method of controlling a gas control valve having a plurality of discrete open configurations including at least a first discrete open configuration providing a first flow rate and a second discrete open configuration providing a second flow rate, different than the first flow rate, the method comprising the step of:

continuously cycling between the first and second discrete open configurations to provide a desired average output flow rate that is different than the first and second flow rates.

2. The method of claim 1 wherein a period of each cycle includes a first residence time in which the valve is maintained in the first discrete open configuration and a second residence time in which the valve is maintained in the second discrete open configuration.

3. The method of claim 2 further comprising the step of adjusting the desired average output flow rate which includes adjusting a ratio of the first residence time to the second residence time.

4. The method of claim 3 wherein the step of adjusting a ratio of the first residence time to the second residence time includes inversely adjusting the first residence time relative to the second residence time such that the period remains substantially constant.

5. The method of claim 3 wherein the step of adjusting a ratio of the first residence time to the second residence time includes adjusting the period of the cycles.

6. The method of claim 1, wherein the gas control valve includes at least one valve member that defines the first discrete open configuration when in a first position and defines the second discrete open configuration when in a second position, wherein the step of cycling includes repeatedly transitioning the at least one valve member between the first and second positions.

7. The method of claim 6, wherein the valve includes a stepper motor arrangement operatively coupled to and operatively driving the at least one valve member and the step of transitioning the at least one valve member includes repeatedly energizing and deenergizing at least one solenoid of the stepper motor arrangement.

8. The method of claim 1, further including stopping continuously cycling between the first and second discrete open configurations and further including the step of maintaining the valve in the first discrete open configuration only.

9. The method of claim 8, wherein the gas control valve includes at least one valve member that defines the first discrete open configuration when in a first position and defines the second discrete open configuration when in a second position, wherein the step of cycling includes repeatedly transitioning the at least one valve member between the first and second positions, wherein the step of maintaining the valve in the first discrete open configuration includes maintaining the valve member in one of the first and second positions.

10. The method of claim 1, where the step of continuously cycling between the first and second discrete open configurations includes cycling into an off configuration, while maintaining a desired average output flow rate sufficient to prevent an attached device from being extinguished.

11. The method of claim 1, prior to the step of continuously cycling between the first and second discrete open configurations, further comprising the step of performing a warm up sequence.

12. The method of claim 11, wherein the step of performing a warm up sequence includes controlling the valve to provide a flow rate that is greater than the desired average output flow rate.

13. The method of claim 12 wherein the step of performing a warm up sequence further includes maintaining the valve in at least one of the plurality of discrete open configurations that provides a flow rate that is greater than the desired average output flow rate.

14. A gas control valve comprising:

a housing having an inlet port and an outlet port;

a fluid flow path between the inlet port and the outlet port;

a flow adjustment arrangement within the fluid flow path having a plurality of discrete open configurations, each of the plurality of discrete open configurations establishing a different unique flow rate through the fluid flow path;

a controller operatively coupled to the flow adjustment arrangement to switch the flow adjustment arrangement between the discrete open configurations, the controller cyclically alternating the flow adjustment arrangement between different ones of the discrete open configurations providing an average flow rate through the fluid flow path that is between the unique flow rates permitted by the different ones of the discrete open configurations.

15. The gas control valve of claim 14, wherein the flow adjustment arrangement includes at least one valve member, the valve member defining, at least in part, the discrete open configurations and a stepper motor operably driving the valve member between the discrete configurations.

16. The gas control valve of claim 15, wherein the stepper motor includes at least one solenoid arrangement.

17. The gas control valve of claim 16, wherein the controller operatively energizes and de-energizes the at least one solenoid to drive the at least one valve member between the discrete open configurations.

18. The gas control valve of claim 14, further including a selector for establishing a user defined flow rate, the selector including a discrete open configuration indicator for each one of the plurality of discrete open configurations, the selector positionable at or between the discrete open configuration indicators.

19. The gas control valve of claim 18, wherein when the selector aligns with one of the discrete open configuration indicators, the controller maintains the flow adjustment arrangement in the discrete open configuration, when the selector is aligned in a stationary position between two discrete open configurations, the controller cyclically alternates the flow adjustment arrangement between the two discrete open configurations.

20. The gas control valve of claim 19, wherein when the selector is aligned between two discrete open configuration indicators, the controller establishes a residence time for each of the two discrete open configurations that the selector is between, the spacing between the selector and the discrete open configuration indicators being inversely proportional to the residence time for the corresponding discrete open configuration.

21. The gas control valve of claim 20, wherein the selector is digital and the distance is a digital representation of a distance.

22. The gas control valve of claim 20, wherein the controller maintains a constant period for any value between two discrete open configurations but only adjusts the ration of the residence times for the two discrete open configurations to adjust the average flow rate permitted by the valve.

23. The gas control valve of claim 15, wherein the valve member and the housing have a plurality of apertures arranged such that varied selection of the number of apertures defines the plurality of discrete open configurations.

24. The gas control valve of claim 15, wherein the flow adjustment arrangement defines at least one off configuration, at least one off configuration such that fluid flow is prevented through the fluid flow path, the controller cyclically alternating the flow adjustment arrangement between different ones of the discrete open configurations and the at least one off configuration providing an average flow rate through the fluid flow path that is between the unique flow rates permitted by the different ones of the discrete open configurations.

25. A method of controlling a gas control valve having a first discrete open configuration providing a first flow rate and a second discrete open configuration providing a second flow rate, different than the first flow rate, and an off configuration preventing fluid flow through the gas control valve, the method comprising the step of:

continuously cycling between the first discrete open configuration and the off configuration to provide a desired average output flow rate that is different than the first flow rate, the desired average output flow rate being sufficient to maintain a flame by an attached device.

26. The method of claim 25, further comprising continuously cycling between the first discrete open configuration, the second discrete open configuration and the off configuration to provide the desired average output flow rate.

27. The method of claim 25, further comprising the steps of:

adjusting the desired average output flow rate to a second desired average output flow rate;

continuously cycling between the first discrete open configuration and the second discrete open configuration time to provide the second desired average output flow rate; and

wherein the step of continuously cycling between the first discrete open configuration and the off configuration and the step of continuously cycling between the first discrete open configuration and the second discrete open configuration are performed at different times.