FIELD OF THE INVENTION
This invention relates generally to pilot gas valves of the type that are intended for use with burner systems that require a continuously or intermittently burning standing pilot. It also relates generally to pilot gas valves that provide safe lighting and complete shutoff in the event that the flame that is heating a thermocouple is extinguished. This invention also relates to a safety shutoff valve that is a pilot gas valve with a pilot flow interrupter for providing pilot gas only. In the preferred embodiment, this construction will work to provide pilot gas only and will not allow full flow of gas when initially activated. Further, this invention relates to such a heater system that utilizes such a pilot gas valve as well as to a method whereby the pilot gas valve used in such a system can be remotely and electronically actuated when required.
BACKGROUND OF THE INVENTION
In the art of heating, the use of gaseous hydrocarbons is well known. This includes natural gas, propane, butane and other hydrocarbon fuels. It is also well known that gas supply valves are used with gas heaters. Such valves are typically used to control the flow of gas and provide safe operation by means of a “thermocouple.” Indeed, the concept of a thermocouple literally means the “coupling” of two dissimilar metals to create a voltage potential between them when heat is maintained. If the heat is not maintained, the voltage potential across the thermocouple is not maintained and the electrical circuit created thereby is opened. The thermocouple is used to monitor a pilot, but its real function is to control the gas supply valve.
By way of example, many gas-fueled heating devices make use of such a pilot light to ignite a main gas burner. In a situation where the pilot light would become extinguished, for any reason, there would also be the potential for uncombusted gas to be released into the surrounding area, thereby creating a serious risk of uncontrolled combustion, explosion and fire. To prevent such a dangerous condition, some gas supply valves use the thermocouple to sense when this pilot light is burning. The tip of the thermocouple is placed in the pilot flame. The resultant voltage, though small (typically greater than 5 mV), operates the gas supply valve responsible for feeding the pilot. So long as the pilot flame remains lit, the thermocouple remains hot and holds the pilot gas valve open. If the pilot light goes out, however, the temperature will fall along with a corresponding drop in voltage across the thermocouple leads, thereby removing power from the valve. The valve closes and shuts off the gas, halting this unsafe condition. The valve disclosed herein further uses a pilot flow interrupter to provide pilot gas only.
In the area of fuel pipelines of the type that are used to transport crude oil, for example, across long distances, it is also well known in the art that heating stations must be placed along the pipeline at intervals that are sufficient to maintain the proper flow viscosity of the oil.
Accordingly, it is an object of the present invention to provide a new and useful pilot valve, system and method that include safe lighting and complete shutoff capabilities in the event that the flame that is heating a thermocouple is extinguished. It is another object to provide a pilot valve with a pilot flow interrupter to provide pilot gas only and not allow full flow of gas when initially opened. It is another object of the present invention to provide such a pilot valve, system and method that can be remotely and electronically actuated when required by the operator. It is still another object of the present invention to provide such a pilot valve and a system using a minimal number of parts to fabricate the pilot valve and system. It is yet another object of the present invention to provide such a method using a minimal number of steps to remotely actuate the pilot valve and system when such is required.
SUMMARY OF THE INVENTION
The remotely actuated pilot valve of the present invention has obtained these objects. It provides for a pilot gas valve that includes safe lighting and complete shutoff capabilities in the event that the flame that is heating a thermocouple is extinguished, the pilot valve having a pilot flow interrupter to provide pilot gas only when initially opened. Further, this invention provides for a heater system that utilizes such a pilot gas valve as well as to a method whereby the pilot gas valve used in such a system can be remotely and electronically actuated when required. Remote actuation is accomplished by use of a solenoid that is incorporated within the valve design and which is controlled by a remote operator.
The foregoing and other features of the present invention will be apparent from the detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front, top and right side perspective view of a gas pilot valve used in accordance with the prior art.
FIG. 2 is a front, top and right side perspective view of a gas pilot valve constructed in accordance with the present invention.
FIG. 3 is a schematic diagram of a system configured in accordance with the present invention.
FIG. 4 is an electrical ladder diagram illustrating the functionality of the gas pilot valve constructed in accordance with the present invention.
FIG. 5 is an enlarged and cross-sectioned front elevational view of the gas pilot valve constructed in accordance with the present invention.
FIG. 6 is a view similar to that of FIG. 5 with elements of the valve shown in another operational position.
FIG. 7 is another view similar to that of FIGS. 5 and 6 with elements of the valve shown in yet another operational position.
FIGS. 8 and 9 show the body of the valve with a partial cross-sectioned view thereof.
DETAILED DESCRIPTION
As a preliminary matter, this application incorporates the teachings of U.S. Pat. No. 9,011,140 issued Apr. 21, 2021 to Carlson (the '140 patent). While drawings numbered 1 through 4 of the '140 patent are generally relevant to the present invention, it should be noted that the drawings numbered 5 through 13 of the '140 patent are not included given the new valve embodiment that is the subject of the present application.
Referring now to the drawings in detail wherein like numbers represent like elements throughout, FIG. 1 illustrates a perspective view of a typical gas pilot valve assembly, generally identified 1, as it would be constructed in accordance with the prior art. As shown, the assembly 1 includes a gas supply line 2 that includes a supply shut off valve 3. A gas valve 5 includes a gas in port 6 and a gas out port 7. The valve 5 also includes a pilot burner gas line 8 and a pilot burner 18. The valve 5 further includes a thermocouple lead 9 and a thermocouple 19. Finally, the valve 5 includes a manual reset button 4. The gas out port 7 of the valve 5 is connected to a heater array 17, the heater array 17 being placed in close proximity to the pilot burner 18 and the thermocouple 19.
In application, gas flows through the supply line 2 and into the gas valve 5 via the in port 6. The valve 5 supplies gas to the heater array 17 via the out port 7. The valve 5 is also used to divert a smaller supply of gas to the pilot burner 18. As long as the thermocouple 19 senses the flame from the pilot burner 18, gas will continue to flow from the valve 5 and into the array 17. If the array 17 ceases to burn gas and generate the necessary amount of heat to maintain the current flow through the thermocouple 19, the current flow from the valve 5 and through the out port 7 will cease at which point it will be necessary to actuate a reset button 4 on the valve 5 and re-light the pilot burner 18 in order to re-open the valve 5 and establish gas flow through it.
Referring now to FIG. 2, it illustrates a perspective view of a gas pilot valve assembly, generally identified 10, as it would be constructed in accordance with the present invention. As shown, the assembly 10 similarly comprises a gas supply line 2 that includes a supply shut off valve 3. A gas valve 20 in accordance with the present invention includes a gas in port 26 and a gas out port 27. The valve 20 also includes a pilot burner gas line out port 28 that is attached to a pilot burner gas line 8 and a pilot burner 18. The valve 20 further includes a thermocouple lead 9 and a thermocouple 19. Significantly different from the assembly that is illustrated in FIG. 1 is the fact that the valve 20 includes an electronic controller 24, an electronically actuated solenoid reset 22 and a manually actuated reset button 21. As with the assembly 1 of the prior art, the gas out port 27 of the valve 20 is connected to a heater array 17, the heater array 17 being placed in close proximity to the pilot burner 18 and the thermocouple 19.
In application, gas flows through the supply line 2 and into the gas valve 20 via the in port 26. The valve 20 supplies gas to the heater array 17 via the out port 27. The valve 20 is also used to divert a smaller supply of gas to the pilot burner 18. As long as the thermocouple 19 senses the flame from the pilot burner 18, gas will continue to flow from the valve 20 and into the array 17. If the array 17 ceases to burn gas and generate the necessary amount of heat that is required to maintain the current flow through the thermocouple 19, the current flow from the valve 20 and through the out port 27 will cease as will the pilot burner 18. At this point, it would be possible for the valve 20 to be reset by means of the manual reset button 21 on the valve 20 and re-light the pilot burner 18 in order to re-open the valve 20 and establish gas flow through it. Alternatively, and preferably, the electronic controller 24 would be used to electronically actuate the solenoid reset 22 to accomplish the same functionality as that of the manual reset button 21. It is to be understood that this construction will also work to provide pilot gas only and will not allow full flow of gas when initially opened. In the assembly 10 of the present invention, it would be possible to configure the valve 20 such that it would include the electronically actuated reset means only, and such is not a limitation of the present invention. In the preferred embodiment of the assembly 10 of the present invention, it is also desirable to configure the electronically actuated reset means such that the controller 24 is remotely actuated.
Referring now to FIG. 3, it illustrates a schematic representation of a preferred embodiment for a remotely and electronically actuated gas valve reset assembly, generally identified 100, that would be configured in accordance with the present invention. Specifically, the gas valve 20 is disposed between a gas supply 2 and a heater 17. These components function substantially in accordance with the detailed description provided above. As shown, however, the gas valve 20 is electronically connected to a programmable logic controller 32 or “PLC” that is used in accordance with a pre-programmed scheme. In this particular configuration, the PLC 32 is, in turn, electronically connected to a receiver 34 and to a transmitter 35. The transmitter 35 is adapted to generate and propagate, by means of an antenna 37, electromagnetic waves 38 of the type that can be received by a remotely located receiver 43, the receiver 43 also being outfitted with an antenna 45. The receiver 43 is electronically connected to a computer which is a monitor or signal generator 40 in this embodiment. This side of the schematically illustrated assembly 100 is intended to be that portion which is capable of controlling the remote actuation of the gas valve 20.
Another side of the assembly shown in FIG. 3 is shown to include a second PLC 33 that is electronically connected to the heater 17. It is to be understood that the first PLC 32 and the second PLC 33 could be one in the same. That is, a single PLC could be used such as where the heater-side PLC 33 is “piggy-backed” by the valve-side PLC 32. Such is not a limitation of the present invention. The second PLC 33 is also electronically connected to the receiver 34 and the transmitter 35 that is adapted to generate and propagate, by means of an antenna 36, electromagnetic waves 38 of the type that can be received by a remotely located second receiver 42, the second receiver 42 also being outfitted with an antenna 44. The second receiver 43 is electronically connected to the monitor or signal generator 40.
In a situation where the gas valve 20 and the heater 17 are shut down, a signal is sent to the second PLC 33 which results in a signal 38 being transmitted from the transmitter 35 via the antenna 37. The signal 38 is picked up by the receiver 43 via the antenna 45 and relayed electronically to the monitor or signal generator 40. At this point, it is to be assumed in this particular embodiment that the heater 17 will need a given amount of time in order to bring the heat up to a level where the remote signal can energize the valve 20. See FIG. 4. In other words, actuation of the pilot light prematurely will result in the pilot light not being sustained, with a second failed condition being relayed to the monitor or signal generator 40. In one practical application, an operator who is not equipped with the remote actuation components as described above would be required to physically go to the place where the heater 17 and gas valve 20 are located, actuate the gas valve 20, wait for a sufficient period of time to reach a sustained heat level, and then manually actuate the gas valve 20, that assembly resembling the type of configuration represented by FIG. 1. This results in substantial time and expense to physically transport the operator to the site of installation of the valve 20 and heater 17 as well as substantial expense related to the operator's “down time” as he or she waits to manually actuate the gas valve 20. In some applications, manual actuation requires that an operator walk into a remote area through woods, snow, rock, etc., and sometimes for miles, to perform this operation.
By contrast, the embodiment illustrated by FIG. 3 allows the operator to assess the situation from the monitor or signal generator 40, or even from a phone line (not shown), and to remotely initiate a reset sequence without the need to be physically in the location of the valve 20 and the heater 17. In this sequence the transmitter 42 and antenna 44 transmit a signal 38 that is picked up by the receiver 34 and antenna 36. The receiver 34 then sends a signal to the PLCs 32, 33 to reignite the heater 17 and allow it sufficient time to reach a sustainable heat level for the valve 20. Once that is done, the operator can use the monitor or signal generator 40 to send a second signal to the valve 20 to allow it to reset automatically, thereby reactivating the operation of the valve 20 and operation of the heater 17 continues as intended. In this particular embodiment, it is also preferred to allow a manual override for operation of the valve 20 in the event of other unanticipated failures, such as where a catastrophic electrical failure would prevent proper operation of the electronics mentioned herein. The use of this type of system in the situation discussed above where an operator would otherwise need to walk into a remote area through woods, snow, rock, etc., and sometimes for miles, to perform manual valve actuation is indeed beneficial. In another application, use of the remote actuation of the gas valve 20 could be beneficial in heater systems where, for example, infrared heaters are located at substantial heights above the floor of a facility where physically reaching them poses a potential hazard for the operator who has to manually actuate a supply gas valve 20. Other applications are also possible and any one of those mentioned here is not a limitation of the present invention.
Referring now to FIG. 4, it shows an electronic ladder diagram of operation of the valve 20 in a system where a “flameless” pre-heater (not shown) is used with the valve 20 and following a situation where the system detects a heating failure, all in accordance with a pre-programmed scheme. Starting at the top of the ladder, it will be seen that, once the remote “ON” signal that is sent remotely by the operator is received by the PLC, the internal relay CR1 normally-open contact is closed. Power is thereby provided to output OUT 1. At the same time, output OUT 2 is on to start heating the flameless pre-heater and to actuate the internal timer TD1 to start timing. In this example, the time delay is pre-programmed at 10 to 15 minutes. During this 10-15 minute period, the flameless pre-heater is heating the tip of the thermocouple. After the internal timer TD1 times out, the TD1 normally-open contact closes thereby energizing output OUT 3 which energizes the electronically-actuated solenoid reset and the internal timer TD2 which starts timing. In this example, the time delay is pre-programmed at 30 to 60 seconds. During this 30 to 60 second period, the solenoid plunger is down and holding the seal open. Gas is flowing to the flameless heater. After the 30 to 60 second period has passed, the TD2 normally-open contact closes thereby energizing internal timer TD3, which is set for a one second time delay. After one second, the TD3 normally-closed contact opens thereby de-energizing the solenoid OUT 3 allowing the solenoid plunger to go up while the seal stays down. The TD3 normally-open contact closes thereby energizing the timer TD4, which is set for a 5 minute time delay. During this 5-minute period, the sensing device will send a signal to the PLC that the flameless heater is in operation by means of OUT 4. After 5 minutes, the TD4 normally-closed contact opens to de-energize the pre-heater and the flameless heater continues to operate properly until its operation is again interrupted for one reason or another. It is to be understood that this example is provided solely for purposes of understanding the operation of the device, system and method of the present invention and is not limiting in any way. Other pre-programmed schemes could be used as well.
Referring now to FIGS. 5-9, they show the detailed internal structure of a remotely actuated pilot valve, again generally identified 20, that is constructed in accordance with the present invention. A gas “in” port 26 and a gas “out” port 27 are provided, as is a pilot burner gas line out port 28. See FIG. 9. Secured atop the valve 20 is the remotely and electronically-actuated solenoid 22, or electrical operator. The solenoid 22 includes electromagnetic windings 54 that are used to create an electromagnetic field within the solenoid 22 when the solenoid 22 is to be actuated. The solenoid 22 includes a spring-loaded plunger 25 that biases the plunger 25 to a first position. In this position, the plunger 25 includes an uppermost end 21 that allows for a manual override of the solenoid 22 when there is no power available. The valve 20 also includes a magnet frame 62 that maintains a magnet disk 64 in contact with the magnet frame 62 when the current through the thermocouple 19 is maintained. When the current is not maintained, as in conditions described earlier, the magnet frame 62 is unable to maintain its connection with the magnet disk 64. This magnet disk 64 is attached to one end of a connector 66, the other end of the connector 66 being attached to a power unit seal 68. The power unit seal 68 is used with a lower seat 69 to stop the flow of gas through the valve 20. See also FIGS. 8 and 9, the latter showing the lower seat 69 and an upper seat 67 by a cut-away view of the valve 20. In the position that is shown in FIG. 6, the solenoid plunger 25 is then movable downwardly when the solenoid 22 is actuated to urge the power unit seal 68 downwardly and away from the lower seat 69 as well. This allows the thermocouple 19 to re-establish electromagnetic connection within the valve 20 and gas flow through the valve 20.
What makes this valve 20 a true safety shutoff valve is the addition of an interrupter subassembly 70 which comprises an interrupter seal 76, a spring 74 and an upper disk 72. In FIG. 5, the coil 54 of the solenoid 22 is not energized and everything is in the non-functioning stand-by mode. Both the gas inlet 26 and the gas outlet 27 are in a safety shutoff position whereby the lower casting seat 69 is blocked by the power unit seal 68.
When the coil of the solenoid 22 is energized, the plunger 25 moves downwardly. The interrupter seal 76 establishes contact with the upper casting seat 67 that is blocking flow from the gas inlet 26 to the gas outlet 27 as it moves the power unit seal 68 off the lower casting seat 69. Until the thermocouple connection 9 receives the >5 mV from the heat source, the coil of the solenoid 22 will need to be energized until the >5 mV is received making a magnetic connection between the magnet disk 64 and the magnet frame 62 and then the coil of the solenoid 22 can be de-energized allowing the plunger 25 to retract re-establishing the flow path from the gas inlet 26 to the gas outlet 27. See FIG. 7. If the thermocouple 19 connection senses flame loss or drops below the 5 mV range will cause the magnet frame 62 to lose holding power which will be overcome by the spring force causing the power unit seal 68 to close. Once that happens, the power unit seal 68 will return to the lower casting seat 69, thereby shutting off the gas flow downstream. FIG. 7 shows the safety valve 20 in its “ON” position where the thermocouple 19 is operating, the lower power unit is holding the magnet frame 62 and the magnet disk 64 together, and the coil has been de-energized and the plunger 25 has retracted.
In summary, the interrupt subassembly 70 which comprises an interrupter seal 76, a spring 74 and an upper disk 72 of the valve 20 show how this construction will work to provide pilot gas only and will not allow full flow of gas when initially opened. FIG. 5 shows the valve 20 at rest with no energy going to the coil. FIG. 6 shows that, when energy is applied to the coil, the plunger 25 moves down pushing open the lower seat 69 and at the same time closing off the upper seat 67 with a seal allowing only pilot gas to flow. FIGS. 8 and 9 show the pilot connection. Once the thermocouple 19 is satisfied the energy can be removed from the coil and the lower seat 69 will stay open and the upper seat 67 returns to its rest position and full gas flow to the burner is established.
Based upon the foregoing, it will be seen that there has been provided a new and useful remotely actuable gas pilot valve that provides safe lighting and complete shutoff in the event that the flame or heat source that is heating a thermocouple is extinguished. There has also been provided a new and useful heater system that utilizes such a pilot gas valve and a method whereby the pilot gas valve used in such a system can be electronically actuated by a remote operator when required.
Patent Application
20220404016
