AIR INLET DAMPER
A fuel fired, atmospheric water heater has a burner positioned inside a combustion chamber. All combustion air entering the combustion chamber must pass through a damper. The damper is operable to adjust the flow resistance to combustion air entering the combustion chamber. The damper is biased to a closed position such that during non-firing periods of the water heater, the damper significantly reduces the flow rate of combustion air being provided to the combustion chamber reducing standby heat loss. An actuator is in fluid communication with a fuel supply line such that when pressurized fuel is provided to the burner, the pressurized fuel causes the actuator to move the damper to an open position to permit operative combustion air delivery to the combustion chamber during firing periods of the water heater.
This application claims priority to U.S. Provisional Patent Application No. 62/202,550 filed Aug. 7, 2015. The present invention relates to an atmospheric water heater and more specifically an atmospheric water heater with an air inlet assembly.
SUMMARYIn one aspect, the invention provides a water heater comprising a combustion chamber; a burner disposed in the combustion chamber; a fuel valve operable to adjust a flow rate of fuel between a first flow rate and a second flow rate greater than the first flow rate; a fuel supply line communicating between the burner and the fuel valve for supply of pressurized fuel from the fuel valve to the burner; an air inlet assembly mounted to the combustion chamber and operable to permit combustion air to enter the combustion chamber, the air inlet assembly including: a damper movable between a first position corresponding to a first resistance to air entering the combustion chamber and a second position corresponding to a second resistance to air entering the combustion chamber, wherein the first resistance is greater than the second resistance; an actuator operable to move the damper between the first position and the second position; a conduit communicating between the actuator and the fuel valve such that the actuator moves the damper to the first position in response to the first flow rate and the actuator moves the damper to the second position in response to the second flow rate.
In another aspect, the water heater is an atmospheric water heater. In another aspect, the actuator has no electrical components. In another aspect, the fuel valve is operable to infinitely adjust the fuel flow rate. In another aspect, the damper resistance is infinitely adjustable as a function of the fuel flow. In another aspect, the actuator includes a diaphragm and a pin, such that the pin is coupled to a first side of the diaphragm and a second side of the pin is in fluid communication with the conduit. In another aspect, the water heater further comprises an arm functionally connecting the actuator and the damper. In another aspect, the water heater further comprises a closure mechanism to bias the damper to the first position. In another aspect, the closure mechanism is a counterweight positioned on the damper. In another aspect, the closure mechanism is a spring. In another aspect, the closure mechanism is achieved by designing the damper so that its own weight biases it to the closed position. In another aspect, the damper translates between the first position and the second position. In another aspect, the damper rotates about an axis from the first position to the second position. In another aspect, the damper includes a front portion and a rear portion; and when the damper is in the second position the front portion is lower than in the first position and the rear portion is higher than in the first position. In another aspect, a flame arrestor is located between the combustion chamber and the air intake assembly such that substantially all the combustion air passing through the air intake assembly must pass through the flame arrestor before arriving in the combustion chamber.
In another aspect, the invention provides a control system for a flow of combustion air to a combustion system of a water heater, the control comprising: a fuel valve for supplying fuel to the combustion system at a selected flow rate; and a damper restricting combustion airflow to a combustion chamber as a function of the fuel flow rate.
In another aspect, the damper is movable between a first position corresponding to a first resistance to combustion air entering the combustion chamber and a second position corresponding to a second resistance to combustion air entering the combustion chamber, wherein the first resistance is greater than the second resistance. In another aspect, an actuator operably moves the damper between a first position corresponding to a first resistance to combustion air entering the combustion chamber and a second position corresponding to a second resistance to combustion air entering the combustion chamber, wherein the first resistance is greater than the second resistance. In another aspect, the actuator has no electrical components. In another aspect, the combustion air being supplied to the combustion chamber is substantially at atmospheric pressure. In another aspect, the damper translates from the first position to the second position. In another aspect, the damper rotates about an axis from the first position to the second position. In another aspect, a closure mechanism biases the damper to the first position. In another aspect, the closure mechanism is a spring. In another aspect, the closure mechanism is a counterweight. In another aspect, the closure mechanism is achieved by designing the damper so that its own weight biases it to the closed position.
In another aspect, the invention provides a method of controlling the flow of combustion air to a combustion system of a water heater, the method comprising: controlling a flow of fuel to the combustion system with a fuel valve; and controlling a flow of combustion air to the combustion system with a damper by setting a flow resistance of the damper as a function of a flow rate of fuel from the fuel valve.
In another aspect, the method of controlling flow of combustion air to a combustion system of a water heater further comprises communicating the fuel valve with the damper via a conduit; wherein controlling a flow of combustion air includes actuating the damper in response to pressure of fuel in the conduit.
In another aspect, the method of controlling flow of combustion air to a combustion system of a water heater further comprises providing an actuator operable in response to pressure; exposing the actuator to pressure of fuel supplied by the fuel valve; and wherein controlling the flow of combustion air includes actuating the damper with the actuator in response to pressure of the supplied fuel. In another aspect, actuating the damper with the actuator includes interconnecting the actuator with the damper by way of an actuator arm.
Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
Before any constructions of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments or constructions and of being practiced or of being carried out in various ways.
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In the illustrated construction, the damper 54 is rotatable about a horizontal axis 70 between a first position (
The damper 54 includes a front portion 74 and a rear portion 78. When the damper 54 is in the second position, the front portion 74 of the damper 54 is lower (i.e., closer to the ground) than the rear portion 78. When the damper 54 is in the first position, the front portion 74 of the damper 54 is adjusted to create a larger inlet area that substantially all the combustion air entering the combustion chamber 30 must pass through, allowing a higher airflow rate. The resistance to combustion air entering the combustion chamber 30 is inversely related to the size of the inlet area such that when the air inlet area is at its maximum the resistance to air entering the combustion chamber is at a minimum. The damper 54 further includes a sealing gasket 80 to create an air-tight seal. The sealing gasket 80 is positioned on the bottom of the rear portion 78 and on the top of the front portion 74. In the illustrated construction, the damper 54 includes an air opening 82 formed therein. The air opening 82 is sized and specifically engineered to calibrate the first airflow rate when the damper 54 is in the first position such that it is only enough to support combustion of a standing pilot. In some constructions, a spacer is positioned between the housing 58 and the damper 54 to create an opening that sets the first airflow rate when the damper 54 is in the first position. In further alternatives, the damper 54 is undersized to create an air gap between the damper 54 and the housing 58 sufficient to set the first airflow rate.
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A first conduit 126 is in fluid communication between the fuel valve 122 and the burner 34, and a second conduit 130 is in fluid communication between the first conduit 126 and the actuator 86. The first conduit 126 may alternatively be referred to as the fuel supply line and the second conduit 130 may alternatively be referred to as the pressure signal line. In the illustrated configuration, the second conduit 130 is connected to a tee 134 formed in the first conduit 126. As an alternative configuration, the second conduit 130 may communicate directly between the fuel valve 122 and the actuator 86 parallel to the first conduit 126, as distinguished from the series-parallel configuration of the first and second conduits 126, 130 illustrated in
Regardless of the configuration of the first and second conduits 126, 130, when gas is supplied to the burner 34 through the first conduit 126, gas is also supplied to the actuator 86 through the second conduit 130. The pressurized gas in the second conduit 130 bears against and acts on the second side 118 of the diaphragm 110, causing the diaphragm 110 to elastically deflect and linearly actuate the pin 98. The un-deflected state of the diaphragm 110 and pin 98 is shown with dashed lines in
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During operation, when heating of the water held in the tank 14 is desired, gas is supplied to the burner 34 from the fuel valve 122 through the first conduit 126 and gas is simultaneously supplied to the actuator 86 through the second conduit 130 (in series-parallel or in parallel, as discussed above). The gas to the burner 34 provides fuel for combustion, and the gas to the actuator 86 provides a pressure signal for moving the damper 54 to the second position. When the damper 54 is in the second position, the damper 54 opens the opening 66 to permit sufficient airflow into the combustion chamber 30 to support complete combustion at the burner 34. The products of combustion are then used to heat the water held in the tank 14 as the products of combustion move from the combustion chamber 30 through the flue 38 and out the exhaust vent 42. Once heating is no longer desired, the fuel valve 122 stops the flow of gas to the burner 34 through the first conduit 126, which also automatically cuts off the gas pressure signal to the actuator 86 through the second conduit 130. As described above, once the flow of gas is stopped, the counterweight 138, torsion springs 142, or other closure mechanism or mechanisms act to quickly move the damper 54 into the first position. Quickly closing the damper 54 drives or purges excess gas from the conduits 126, 130. Once the damper 54 is in the first position, the airflow rate is reduce to an amount for supporting a standing pilot only and significantly reduces heat loss from excess air moving through the combustion chamber 30 and the flue 38 when combustion at the burner 34 is not occurring.
As such, the air inlet assembly 50 is an energy saving device that is designed to limit the amount of air allowed to enter the combustion chamber 30 when the burner 34 is not operational to avoid losing heat to the environment through the flue 38. The air inlet assembly 50 has two distinct functional positions (i.e., a high airflow rate position permitting sufficient airflow for burner operation and a low airflow rate position permitting sufficient airflow for pilot burner operation). Alternatively, the air inlet assembly may be designed for any of an infinite range of positions corresponding to an infinite number of flow resistances (e.g., for use with a modulating burner). When the burner 34 is not operational, the air inlet assembly 50 is in the low airflow rate position to minimize inefficiencies.
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The fuel valve 122E includes a pressure testing port or dedicated port 224 for communicating with one end of the second conduit 130E. The opposite end of the second conduit 130E communicates with the actuator 86E via a pressurized gas inlet 132E. The second conduit 130E is configured in parallel with the first conduit 126E because they both communicate directly with the fuel valve 122E.
The actuator 86E is supported by a bracket 228 that extends from the combustion chamber housing or combustion or chamber door. The actuator 86 is mounted inside the bracket 228 such that the actuator 86E is between the bracket and the water heater 10E, such that the bracket provides some protection for the actuator 86E. The actuator 86E in this construction is possibly more serviceable than previously-discussed constructions since it is mounted on an exterior surface of the water heater 10E and is more readily accessible by a service technician than an actuator 86 mounted under the water heater 10.
The actuator 86E is similar to the previously-described actuators 86 which include a diaphragm 110E and a pin 98E for converting the gas pressure signal from the second conduit 130E into linear motion. Because the actuator 86E is mounted on the side of the water heater 10E with the diaphragm 110E essentially vertical and the pin 98E essentially horizontal, the actuator 86E is relatively far away from the air inlet assembly 50E. The configuration includes a push rod 232 that extends vertically down and horizontally through the base ring 170E to connect with the arm 106E that is used to move the damper 54E to the second position.
A joint 236 between the push rod 232 and the arm 106E accommodates essentially horizontal movement of the push rod 232 with respect to the pivoting arm 106E (which is pivoting about the axis 70E of the damper 54E). The joint 236 includes a necked-down segment 240 of the push rod 232 within a circular hole 244 in the arm 106E. The necked-down segment 240 is of smaller diameter than the hole 244, such there is room for the necked-down segment within the hole 244 as the arm 106E pivots about the axis 70E.
Claims
1. A water heater comprising:
- a combustion chamber;
- a burner disposed in the combustion chamber;
- a fuel valve operable to adjust a flow rate of fuel between a first flow rate and a second flow rate greater than the first flow rate;
- a fuel supply line communicating between the burner and the fuel valve for supply of pressurized fuel from the fuel valve to the burner;
- an air inlet assembly mounted to the combustion chamber and operable to permit combustion air to enter the combustion chamber, the air inlet assembly including: a damper movable between a first position corresponding to a first resistance to air entering the combustion chamber and a second position corresponding to a second resistance to air entering the combustion chamber, wherein the first resistance is greater than the second resistance; an actuator operable to move the damper between the first position and the second position; a conduit communicating between the actuator and the fuel valve such that the actuator moves the damper to the first position in response to the first flow rate and the actuator moves the damper to the second position in response to the second flow rate.
2. The water heater of claim 1, wherein the water heater is an atmospheric water heater.
3. The water heater of claim 1, wherein the actuator has no electrical components.
4. The water heater of claim 1, wherein the fuel valve is operable to infinitely adjust the fuel flow rate.
5. The water heater of claim 4, wherein the damper resistance is infinitely adjustable as a function of the fuel flow rate.
6. The water heater of claim 1, wherein the actuator includes a diaphragm and a pin, such that the pin is coupled to a first side of the diaphragm and a second side of the pin is in fluid communication with the conduit.
7. The water heater of claim 1, further comprising an arm functionally connecting the actuator and the damper.
8. The water heater of claim 1, further comprising a closure mechanism to bias the damper to the first position.
9. The water heater of claim 8, wherein the closure mechanism is a counterweight positioned on the damper.
10. The water heater of claim 8, wherein the closure mechanism is a spring.
11. The water heater of claim 8, wherein the closure mechanism is achieved by designing the damper so that its own weight biases it to the closed position
12. The water heater of claim 1, wherein the damper translates between the first position and the second position.
13. The water heater of claim 1, wherein the damper rotates about an axis from the first position to the second position.
14. The water heater of claim 1, wherein the damper includes a front portion and a rear portion; and when the damper is in the second position the front portion is lower than in the first position and the rear portion is higher than in the first position.
15. The water heater of claim 1, wherein a flame arrestor is located between the combustion chamber and the air intake assembly such that substantially all the combustion air passing through the air intake assembly must pass through the flame arrestor before arriving in the combustion chamber.
16. A control system for a flow of combustion air to a combustion system of a water heater, the control comprising:
- a fuel valve for supplying fuel to the combustion system at a selected flow rate; and
- a damper restricting combustion airflow to a combustion chamber as a function of the fuel flow rate.
17. A control system of claim 16, wherein the damper is movable between a first position corresponding to a first resistance to combustion air entering the combustion chamber and a second position corresponding to a second resistance to combustion air entering the combustion chamber, wherein the first resistance is greater than the second resistance.
18. A control system of claim 16, wherein an actuator operably moves the damper between a first position corresponding to a first resistance to combustion air entering the combustion chamber and a second position corresponding to a second resistance to combustion air entering the combustion chamber, wherein the first resistance is greater than the second resistance.
19. A control system of claim 16, wherein the actuator has no electrical components.
20. A control system of claim 16, wherein the combustion air being supplied to the combustion chamber is substantially at atmospheric pressure.
21. A control system of claim 17 wherein the damper translates from the first position to the second position.
22. A control system of claim 17, wherein the damper rotates about an axis from the first position to the second position.
23. A control system of claim 17, wherein a closure mechanism biases the damper to the first position.
24. A control system of claim 23, wherein the closure mechanism is a spring.
25. A control system of claim 23, wherein the closure mechanism is a counterweight.
26. The water heater of claim 23, wherein the closure mechanism is achieved by designing the damper so that its own weight biases it to the closed position
27. A method of controlling the flow of combustion air to a combustion system of a water heater, the method comprising:
- controlling a flow of fuel to the combustion system with a fuel valve; and
- controlling a flow of combustion air to the combustion system with a damper by setting a flow resistance of the damper as a function of a flow rate of fuel from the fuel valve.
28. The method of claim 27, further comprising communicating the fuel valve with the damper via a conduit; wherein controlling a flow of combustion air includes actuating the damper in response to pressure of fuel in the conduit.
29. The method of claim 27, further comprising providing an actuator operable in response to pressure; exposing the actuator to pressure of fuel supplied by the fuel valve; and wherein controlling the flow of combustion air includes actuating the damper with the actuator in response to pressure of the supplied fuel.
30. The method of claim 29, wherein actuating the damper with the actuator includes interconnecting the actuator with the damper by way of an actuator arm.
Type: Application
Filed: Aug 5, 2016
Publication Date: Feb 9, 2017
Inventors: Robert Frederick Poehlman (Cudahy, WI), Janice Fitzgerald (Mequon, WI), J. Eric Arnold (Jonesborough, TN), Timothy Mitchel Smith (Blountville, TN), Chad Taylor Thompson (Dandridge, TN), George W. Kraus, II (Johnson City, TN), Duane A. Lee (Johnson City, TN)
Application Number: 15/229,664