Patent Application
20240035668
The present invention relates to providing a redundant safety shutoff valve for gas appliances that has a leak rate of no greater than 20 cc/hr which is externally controlled, preferably as an electronic solenoid valve.
There are environmental concerns expressed relating to the amount of methane gas released into the atmosphere. Gas ranges are a target of this concern, even when in the off position. One reason for these concerns relating to release of methane when a gas range is in the off position is that a standard four top burner gas range configuration has up to 14 gas connections inside the appliance where gas may be present 100% of the time (on or off, 24 hours a day). This may provide significantly more connections than other gas appliances such as dryers, furnaces, water heaters, etc. which may have only 2-3 connections to contend with on average. Many of these connections are operated valves which each potentially direct gas flow to specific locations, like top burners, when open.
CSA permits a leak rate of 230 cc/hr for components used in gas appliances. Typically, the customer targets the same leak rate (230 cc/hr) for the entire appliance when in the off position. With up to 14 potential leak sources, some new appliances may fail this standard.
Many gas appliances, other than gas ranges, require redundant solenoid valve constructions having two solenoids within a single housing which has an inlet and outlet with the two solenoids in series between the inlet and the outlet. These double solenoid valves are typically large and have a configuration which limits how and where they can be positioned.
The applicant was recently requested by customers to quote supplying similar double solenoid valves to customers for use with gas ranges. The added safety feature of a double solenoid gas valve is that there would be two valve seats which must be open to permit the flow of gas to an oven or broil burner. Double solenoid gas valves are significantly more expensive than single solenoid gas valves, particularly when coupled with the cost of the electronics which would monitor the solenoids. While double solenoid gas valves throughout a range could provide redundancy, such redundancy would certainly come with an increased cost.
Improved gas ranges are believed to be desirable which may be less prone to leakage than prior art appliances.
It is an object of many embodiments of the present invention to provide an improved gas appliance.
It is another object of many embodiments of the present invention to provide a gas appliance having a redundant shutoff valve.
It is yet another object of many embodiments of the present invention to provide a gas appliance having a solenoid shutoff valve disposed upstream of the gas regulator.
Accordingly, providing a positive gas shutoff valve to the appliance at the inlet (upstream from a gas regulator), could eliminate all leak points downstream. This positive shutoff valve, when shut, could be the only potential leak point of the entire system, with backup shutoff being at the other valves of the appliance.
The gas appliance, whether a range or other appliance, has an off configuration which means that it does not intend to consume gas. Some gas may leak by (hopefully within specification). An on configuration exists when at least one function of the appliance intends to consume gas, such as at least one burner being lit, etc. . . . The applicant has at least one solenoid valve capable of meeting the 20 cc/hr leak rate when shut which could function as a master shutoff solenoid upstream of a pressure regulator. One particular solenoid valve has a rating of roughly 119,000 BTU/hr which exceeds the requirement for most gas stoves in the United States. This particular valve is also CE rated, permitting use in appliances in Europe. However, this valve, by itself, is not redundant. It is only with the placement of this valve upstream of a gas regulator in a gas range, that it then can provide the desired redundancy, preferably when coupled to electronics that control the operation of the valve which can provide the logic of if all valves are off, then the master or positive shutoff valve would be shut as well. Other embodiments may have sensors that detect when functions are off and then a processor could send a signal to shut off the master shut off valve. Other valves may have other ratings.
By providing the electrically controlled positive or master shutoff at or near the inlet to the appliance, and preferably at least upstream of a pressure regulator, two separate issues can be simultaneously addressed: (a) the allowable off position leak rate may be cut by up to 90%, and (b) redundancy may be satisfactorily addressed.
A master shutoff valve in communication with the gas inlet, such as between the inlet and a gas regulator, could work in series with separate, potentially smaller, solenoids downstream of a gas pressure regulator. This series arrangement of valves allows the use of smaller single coil solenoids that would likely prove to be more flexible as to where they could be positioned.
For many embodiments, providing a master shut off with redundancy would employ two valves for a single burner system or three valves for a two burner system, and an electronic ignition system (since when the master shutoff valve is shut, there will not be a flow or supply of gas available for a pilot light).
With such a construction, the first valve (master shutoff valve) provides enough BTU capacity to provide flow (when open) for the entire gas range: i.e., enough for all of the top burners, as well as the bake and broil elements. The first valve would also need to provide the desired minimum leak amount, in this case, no more than 20 cc/hr or less. Second and third valves could control the bake and broil burners, if a two burner system. An electronics module would preferably control ignition, flame supervision, and provide valve drive for both bake and broil valves.
When in the off position, no gas is provided downstream of the first valve: gas is preferably stopped at the master solenoid valve at the inlet. When there is a call for heat, the electronics provides a signal to the first valve (master solenoid) to open. Gas then flows as directed toward the bake and broil elements, but first would need to pass through the appropriate bake solenoid valve (second solenoid valve) or broil solenoid valve (third solenoid valve) depending upon the particular operation, or function, desired for the range. The valves (first, second, third, etc.) have at least an on and an off position. Some valves, such as second, third, etc., may be able to adjust gas flow as well when in the on position as would be known by those of ordinary skill in the art. When in the off position, no gas (apart from possible unintended leakage) flows through the valve, whether it be the first, second, third or other valve.
If the direction is for bake, the bake solenoid would open, the electronics would ensure ignition, and the desired temperature and flame would be monitored as directed by the user together with the electronics module. If ignition is not completed in a specified amount of time, the entire system (including the first valve) would shut down, i.e., the master solenoid valve would shut. The electronics module may permit a selected number of purge attempts before potentially shutting down the appliance completely until a service technician permitted continued attempts.
Apart from bake and broil burners (and their second and third valves) for a two burner system, top burners, electrodes (bake and broil) which could act as both igniters and flame sense could be provided, gas pressure regulation systems, and other systems could be provided with more sophisticated ranges. Other gas appliances may benefit from the technology disclosed herein.
The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings in which:
A gas appliance 10 in the form of a gas range is shown of relatively straight forward complexity in
Many gas ranges regardless of the sophistication of their top burners 12-18 will have at least a bake burner 42 controlled with a solenoid or bi-metal valve, in this case identified as second solenoid valve 38. Many gas ranges will also have a broil burner 40 which may be controlled by solenoid or bi-metal valve, in this case identified as third solenoid valve 36.
The solenoid valves receive input to open from an electronic module 46, which may also include a touch display 47 for the user to control operation of the appliance 10. Bake and broil burners 42,40 will also have corresponding electronic ignition systems 48,50 to ignite the burners when desired which may also provide ignition/flame sensors.
When the stove or appliance 10 is off for prior art appliances similar to the one illustrated, gas would proceed from an external source 60 (either natural gas, propane, etc.) normally at a residential home through a gas regulator 62 to manifold 64 supplying the various valves 20-26, 36,38. Gas would be within the manifold 64 at 100%, 24 hours a day. However, the applicant has installed a master solenoid valve, first valve 44 to prevent such a situation.
The first valve 44 has an open and a shut configuration. The first valve 44 is opened when the electronic control module 46 receives an input requiring heat at any of the top burners 12-18 or the bake or broil burner 42,40. The first valve 44 is further shut by the electronic control module 46 when no signal is received, such as in the event of power failure, or when the electronic control module 46 recognizes an off condition of the range, such as if none of the top burners 12-18 and the oven (both bake and broil burners 42,40 are off).
First valve 44 can preferably located at or near the inlet 66 upstream of the pressure regulator 62 so that it may solve two issues at the same time: (a) cut the allowable off position leak rate by up to or exceeding 90% of the allowable leak rate (or permit achieving a minimal leak rate), and (b) add redundancy, so that if any of the other valves in the system were to leak by, shutting the first valve 44 would secure gas pressure upstream of that valve to no more than the gas in the manifold 64. Preferable first valves 44 can achieve a 20 cc/hr or less leak rate which is significantly less than the 230 cc/hr leak rate permitted by CSA standards. [At least some first valves 44 manufactured by the applicant have a rating of 119,000 BTU/hr which is greater than the BTU requirements for most gas ranges sold into the United States.] Other valves may be rated differently.
Furthermore, many first valves 44 may already be CE rated for sale into the European market.
Having a master shut off valve, first valve 44, at the inlet 66 could work in series with separate smaller solenoid valves (such as 36,38) downstream of the gas pressure regulator 62. Such a series arrangement could allow for the use of smaller single coil solenoid valves that could prove to be more flexible as to where they may be positioned.
Providing a first valve 44 provides redundancy not known by the applicant such as by providing first valve 44 in combination with a second solenoid valve utilized with a single burner system or providing first valve 44 in combination with second and third solenoid valves with a two burner system. In all of these embodiments, an electronic ignition module is preferably provided either as a portion of the electronic control module 46 or separately as electronic ignition systems 52-58 and 48, 50 for the various burners. The electronic control module 46 may control ignition to the various burners as well as possibly monitor the existence of a flame at any of the various burners.
In these various embodiments, the first valve 44 has enough BTU capacity to supply the entire range 10 (enough for all top burners, bake and broil burners). The first valve 44 is also preferably manufactured in an effort to meet a predetermined maximum leak rate, currently 20 cc/hr, but other specification could be provided for other embodiments. The second, third and other solenoid valves 36,38 (20-28, and/or others) are all in series, possibly separately with the first valve 44. These other valves 36,38, 20-28, etc. also control the bake, broil elements, top elements, etc. The electronic module 46 controls ignition, flame supervision, valve drive for both bake and broil valves, as well as possibly the top burners, if they employ solenoid valves as well.
In the off position, no gas is received downstream of the first valve 44. The electronic module 46 may have a signal sent to have the various valves, including the first valve 44, second valve 38, third valve 36, etc., in the off position. Gas stops as the inlet of the first valve 44. When there is a call for heat, or other gas use, by a portion of the appliance 10, the electronic control module 46 sends a signal to open the first valve 44,. Gas then proceeds toward the appropriate burner, such as a bake or broil burner, by way of example. The appropriate solenoid valve for the appropriate burner is either then opened or is simultaneously opened with the opening of the first valve 44. If the call is for bake, the bake solenoid opens, and the electronic control module 46 preferably monitors to ensure ignition within a specified amount of time along with having the second valve 38 positioned to open along with the first valve 44. If the ignition process is not completed within the specified amount of time, the specific solenoid is shut (such as the bake or second solenoid valve 38). The first solenoid valve 44 is also shut when shutting the second solenoid valve 38 (for some embodiments, the electronic module 46 will employ logic to ensure no other valve is open providing heat before directing the first valve 44 to be shut. If the bake solenoid were the only burner supposed to be working, then the electronic control module 46 could allow a specified amount of purge times and attempt a set number of relighting attempts before shutting down completely (which would shut the first valve 44, potentially regardless of other operations of the appliance 10 desired at the time). For bake valves, the electronic control module 46 could control the amount of gas flow through the valve to attempt to provide a specific bake temperature. If a call is to broil, the third valve 36 may be opened with the first valve 44 by the electronic control module 46.
Other components could be added to the system apart from just a single burner controlled by a second solenoid valve having a corresponding electronic ignition control for varying degrees of complexity and sophistication. Bake and broil elements both could be provided with corresponding solenoid valves; electrodes (possibly for both bake and broil) could be provided which act as both ignitors and flame sensors could be used with the electronic ignition controls; gas pressure regulation and other features could also be provided.
Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to the preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.
This application claims the benefit of U.S. Provisional Application No. 63/392,198 filed Jul. 26, 2022, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63392198 | Jul 2022 | US |
