CA2483762A1 - Flammable vapour detector system for hot water heater - Google Patents
Flammable vapour detector system for hot water heater Download PDFInfo
- Publication number
- CA2483762A1 CA2483762A1 CA002483762A CA2483762A CA2483762A1 CA 2483762 A1 CA2483762 A1 CA 2483762A1 CA 002483762 A CA002483762 A CA 002483762A CA 2483762 A CA2483762 A CA 2483762A CA 2483762 A1 CA2483762 A1 CA 2483762A1
- Authority
- CA
- Canada
- Prior art keywords
- combustion chamber
- gas
- gas valve
- flammable
- detector system
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N5/00—Systems for controlling combustion
- F23N5/02—Systems for controlling combustion using devices responsive to thermal changes or to thermal expansion of a medium
- F23N5/10—Systems for controlling combustion using devices responsive to thermal changes or to thermal expansion of a medium using thermocouples
- F23N5/107—Systems for controlling combustion using devices responsive to thermal changes or to thermal expansion of a medium using thermocouples using mechanical means, e.g. safety valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N5/00—Systems for controlling combustion
- F23N5/24—Preventing development of abnormal or undesired conditions, i.e. safety arrangements
- F23N5/247—Preventing development of abnormal or undesired conditions, i.e. safety arrangements using mechanical means
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Control Of Combustion (AREA)
Abstract
A flammable vapour detector system is comprised of a thermocouple which is mounted in a combustion chamber of a hot water heater. A combustion air intake means supplies combustion air to the combustion chamber. A gas burner is provided in the combustion chamber. A gas supply line is secured to the gas burner. An external gas valve is provided in the supply line. A gas valve control circuit controls the ON/OFF state of the external gas valve. The gas valve control circuit is connected to the thermocouple.
The thermocouple is exposed to the combustion chamber to sense the temperature therein and is set to cause the control circuit to shut off the external gas valve when the temperature in the combustion chamber reaches a set predetermined temperature value upon burning flammable vapours as they propagate in the combustion chamber through the combustion air intake means.
The thermocouple is exposed to the combustion chamber to sense the temperature therein and is set to cause the control circuit to shut off the external gas valve when the temperature in the combustion chamber reaches a set predetermined temperature value upon burning flammable vapours as they propagate in the combustion chamber through the combustion air intake means.
Description
FLAMMABLE VAPOUR DETECTOR SYSTEM
FOR HOT WATER HEATER
TECHNICAL FIELD
toooi) The present invention relates to a flammable vapour detector system for shutting off the burner of a combustion chamber located in a hot water heater upon detection of flammable vapours within the burner chamber.
BACKGROUND ART
tooo2) Various devices have been developed in recent years for detecting flammable gases in the area of a gas-fired hot water heater. Most systems use gas sensors which are located in proximity to the air intake for the combustion chamber and upon detection of same, the burners are shut down. These sensors are capable of sensing a variety of explosive gas, such as natural gas, methane, propane, butane, gasoline, solvents and paints. Also, the air intakes leading to the combustion chamber are usually elevated from the floor surface or else the entire hot water heater is supported on an elevated base whereby to elevate the air intake from the floor. Regulations are in place concerning the installation of gas-fired hot. water heaters and it is recommended that they be mounted with their air intake at least 18" from the floor surface. Because natural gas is lighter than air, gas detectors must be installed adjacent a ceiling close to the hot water heater whereas detectors for heavier gases such as propane, gasoline vapours and kerosene, are located close to the floor as these gases are heavier than air. Accordingly, it is preferable to have two detectors associated with such water heaters.
toao3) A problem with using gas sensors is that many of these sensors do not operate effectively and often malfunction. Accordingly, they are not entirely reliable.
FOR HOT WATER HEATER
TECHNICAL FIELD
toooi) The present invention relates to a flammable vapour detector system for shutting off the burner of a combustion chamber located in a hot water heater upon detection of flammable vapours within the burner chamber.
BACKGROUND ART
tooo2) Various devices have been developed in recent years for detecting flammable gases in the area of a gas-fired hot water heater. Most systems use gas sensors which are located in proximity to the air intake for the combustion chamber and upon detection of same, the burners are shut down. These sensors are capable of sensing a variety of explosive gas, such as natural gas, methane, propane, butane, gasoline, solvents and paints. Also, the air intakes leading to the combustion chamber are usually elevated from the floor surface or else the entire hot water heater is supported on an elevated base whereby to elevate the air intake from the floor. Regulations are in place concerning the installation of gas-fired hot. water heaters and it is recommended that they be mounted with their air intake at least 18" from the floor surface. Because natural gas is lighter than air, gas detectors must be installed adjacent a ceiling close to the hot water heater whereas detectors for heavier gases such as propane, gasoline vapours and kerosene, are located close to the floor as these gases are heavier than air. Accordingly, it is preferable to have two detectors associated with such water heaters.
toao3) A problem with using gas sensors is that many of these sensors do not operate effectively and often malfunction. Accordingly, they are not entirely reliable.
There is therefore a need to provide a more reliable way of detecting explosive flammable vapours.
SUMMARY OF INVENTION
Iooo4) It is a feature of the present invention to provide a flammable vapour detector system which overcomes the above-mentioned disadvantages of the prior art.
(00051 According to a broad aspect, the present invention provides a flammable vapour detector system which comprises a thermocouple mounted in the combustion chamber of a hot water heater. A combustion air intake means supplies combustion air to the combustion chamber. A gas burner is provided in the combustion chamber. A gas supply line is secured to the gas burner. An external gas valve is provided in the supply line. A gas valve control circuit controls the ON/OFF state of the external gas valve. The gas valve control circuit is connected to the thermocouple.
The thermocouple is exposed to the combustion chamber to sense the temperature therein and is set to cause the control circuit to shut off the external gas valve when the temperature in the combustion chamber reaches a set predetermined temperature value upon burning flammable vapours as they propagate in the combustion chamber through the combustion air intake means.
BRIEF DESCRIPTION OF DRAWINGS
Iooos) A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which:
tooo7) FIGURE 1 is a schematic view of the flammable vapour detector system of the present invention utilized in conjunction with a combustion chamber of a hot water heater.
DESCRIPTION OF PREFERRED EMBODIMENTS
toooa7 Referring now to the drawing, there is shown the lower portion 10 of a hot water heater. The schematic illustration does not show all of the component parts of the lower end of the hot water heater but the illustration is only schematic. Therefore, the inner casing of the hot water heater as well as the outer casing, pipes and controls are not illustrated.
tooo9) At the lower end of the hot water heater, there is provided a combustion chamber 12 in which there is secured a gas burner 12. A gas line 13 supplies combustible gas, herein natural gas, to the gas burner 12. The gas line 13 is connected to the gas supply line 14 through a main gas valve 15. Combustible air is supplied to the combustion chamber 11 through air intake means, and as herein shown, via a snorkel 16 which is a channel provided with an elevated air intake port 17 whereby to admit air at a predetermined elevation from a support floor 18 on which rests the hot water heater 10. Accordingly, combustion air enters the inlet port and propagates down into the snorkel to enter the combustion chamber 11. The hot water heater could also be supported on an elevating base if the air intake is at the bottom of the heater whereby to elevate the air intake.
toooZO1 The,present invention provides a thermocouple 19 which is mounted at a predetermined location within the combustion chamber 11 and which is connected to a high limit cut-off normally closed switch 20 and they constitute a control circuit. Power supply for the main gas valve is provided through the connection 21 from the normally closed switch 20. The thermocouple is exposed to the combustion chamber to sense the temperature. therein and it has a set point whereby to cause the normally closed switch to open upon sensing the set predetermined temperature whereby to cause the main gas valve to shut down and stop the gas supply to the burner 12. By shutting the main gas valve, the gas supply to other appliances 25 is also shut-off to prevent explosion.
SUMMARY OF INVENTION
Iooo4) It is a feature of the present invention to provide a flammable vapour detector system which overcomes the above-mentioned disadvantages of the prior art.
(00051 According to a broad aspect, the present invention provides a flammable vapour detector system which comprises a thermocouple mounted in the combustion chamber of a hot water heater. A combustion air intake means supplies combustion air to the combustion chamber. A gas burner is provided in the combustion chamber. A gas supply line is secured to the gas burner. An external gas valve is provided in the supply line. A gas valve control circuit controls the ON/OFF state of the external gas valve. The gas valve control circuit is connected to the thermocouple.
The thermocouple is exposed to the combustion chamber to sense the temperature therein and is set to cause the control circuit to shut off the external gas valve when the temperature in the combustion chamber reaches a set predetermined temperature value upon burning flammable vapours as they propagate in the combustion chamber through the combustion air intake means.
BRIEF DESCRIPTION OF DRAWINGS
Iooos) A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which:
tooo7) FIGURE 1 is a schematic view of the flammable vapour detector system of the present invention utilized in conjunction with a combustion chamber of a hot water heater.
DESCRIPTION OF PREFERRED EMBODIMENTS
toooa7 Referring now to the drawing, there is shown the lower portion 10 of a hot water heater. The schematic illustration does not show all of the component parts of the lower end of the hot water heater but the illustration is only schematic. Therefore, the inner casing of the hot water heater as well as the outer casing, pipes and controls are not illustrated.
tooo9) At the lower end of the hot water heater, there is provided a combustion chamber 12 in which there is secured a gas burner 12. A gas line 13 supplies combustible gas, herein natural gas, to the gas burner 12. The gas line 13 is connected to the gas supply line 14 through a main gas valve 15. Combustible air is supplied to the combustion chamber 11 through air intake means, and as herein shown, via a snorkel 16 which is a channel provided with an elevated air intake port 17 whereby to admit air at a predetermined elevation from a support floor 18 on which rests the hot water heater 10. Accordingly, combustion air enters the inlet port and propagates down into the snorkel to enter the combustion chamber 11. The hot water heater could also be supported on an elevating base if the air intake is at the bottom of the heater whereby to elevate the air intake.
toooZO1 The,present invention provides a thermocouple 19 which is mounted at a predetermined location within the combustion chamber 11 and which is connected to a high limit cut-off normally closed switch 20 and they constitute a control circuit. Power supply for the main gas valve is provided through the connection 21 from the normally closed switch 20. The thermocouple is exposed to the combustion chamber to sense the temperature. therein and it has a set point whereby to cause the normally closed switch to open upon sensing the set predetermined temperature whereby to cause the main gas valve to shut down and stop the gas supply to the burner 12. By shutting the main gas valve, the gas supply to other appliances 25 is also shut-off to prevent explosion.
tooozil The system works as follows . As flammable vapours enter the snorkel 16 with the air supply, they are burned by the gas burner 12 and these additional flammable vapours burn and thereby raise the temperature in the combustion housing. The thermocouple 19 is set to open the switch 20 upon detection of a predetermined temperature value when flammable vapours are being burned in the combustion chamber. Accordingly, as the temperature in the combustion chamber rises due to infiltration of external flammable combustible products, the main gas valve shuts dawn the gas supply and the gas burner is extinguished to prevent an explosion. Other appliances are also shut down.
The predetermined temperature value is set higher than the temperature generated by the burner from the combustible gas and air mixture without the flammable vapours mixed therewith.
foooiz~ The nofmally closed contact switch 20 supplies a 25 milli-amp_ current to the main gas valve through connection 2l, to maintain that gas valve open to supply gas to the burner. When the current is cut off by opening the switch 20, then the main gas valve shuts'down automatically.
foool3~ The above flammable vapour detector system of the present invention is an economical, safe and efficient way of shutting down the burner in the combustion chamber of a gas fired hot water heater upon detection of flammable vapours and does not rely on gas sensors which often malfunction and which require separate power supplies.
toooi4l It is within the ambit of the present invention to cover any obvious modifications of the preferred embodiment described herein, provided such modifications fall within the scope of the appended claims.
The predetermined temperature value is set higher than the temperature generated by the burner from the combustible gas and air mixture without the flammable vapours mixed therewith.
foooiz~ The nofmally closed contact switch 20 supplies a 25 milli-amp_ current to the main gas valve through connection 2l, to maintain that gas valve open to supply gas to the burner. When the current is cut off by opening the switch 20, then the main gas valve shuts'down automatically.
foool3~ The above flammable vapour detector system of the present invention is an economical, safe and efficient way of shutting down the burner in the combustion chamber of a gas fired hot water heater upon detection of flammable vapours and does not rely on gas sensors which often malfunction and which require separate power supplies.
toooi4l It is within the ambit of the present invention to cover any obvious modifications of the preferred embodiment described herein, provided such modifications fall within the scope of the appended claims.
Claims (5)
1. A flammable vapour detector system comprising a thermocouple mounted in a combustion chamber of a hot water heater, combustion air intake means to supply combustion air to said combustion chamber, a gas burner in said chamber, a gas supply line secured to said gas burner, an external gas valve in said supply line, a gas valve control circuit to control the ON/OFF state of said external gas valve, said gas valve control circuit being connected to said thermocouple, said thermocouple being exposed to said combustion chamber to sense the temperature therein and being set to cause the control circuit to shut off said external gas valve when said temperature in said combustion chamber reaches a predetermined set temperature value upon burning flammable vapours as they propagate in said combustion chamber through said combustion air intake means.
2. A flammable vapour detector system as claimed in claim 1 wherein said predetermined value is higher than the temperature generated by said burner from the combustible gas and air mixture without flammable vapours mixed therewith.
3. A flammable vapour detector system as claimed in claim 2 wherein said control circuit comprises a normally closed (N.C.) switch through which is supplied a current to maintain said gas valve open to supply gas to said burner.
4. A flammable vapour detector system as claimed in claim 3 wherein said thermocouple opens said N.C. switch upon sensing said predetermined set temperature value to cut off said current to cause said gas valve to close and shut off gas supply to said burner to extinguish same.
5. A flammable vapour detector system as claimed in claim 2 wherein said combustion air intake means is a snorkel having an elevated air intake port to admit ambient combustion air to said combustion chamber.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US10/681,227 US20050079459A1 (en) | 2003-10-09 | 2003-10-09 | Flammable vapour detector system for hot water heater |
| US10/681,227 | 2003-10-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2483762A1 true CA2483762A1 (en) | 2005-04-09 |
Family
ID=34422246
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002483762A Abandoned CA2483762A1 (en) | 2003-10-09 | 2004-10-04 | Flammable vapour detector system for hot water heater |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US20050079459A1 (en) |
| CA (1) | CA2483762A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2444109B (en) * | 2006-11-22 | 2011-04-20 | Valor Ltd | Heating apparatus |
| EP4123241A1 (en) | 2021-07-22 | 2023-01-25 | BDR Thermea Group B.V. | System and method for detecting a backflow of a fluid in a combustion chamber of a boiler |
Family Cites Families (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3213921A (en) * | 1962-10-30 | 1965-10-26 | Nat Tank Co | Combustion control |
| US3405690A (en) * | 1966-11-15 | 1968-10-15 | Combustion Eng | Method of and means for operating fired processing equipment |
| US3740688A (en) * | 1969-12-11 | 1973-06-19 | Robertshaw Controls Co | Fusible link assembly |
| US3645662A (en) * | 1970-02-25 | 1972-02-29 | Gordon Mclarty | Safety switch and circuit for oil-burning furnace |
| US4221557A (en) * | 1978-06-12 | 1980-09-09 | Gas Research Institute | Apparatus for detecting the occurrence of inadequate levels of combustion air at a flame |
| US5533495A (en) * | 1995-02-28 | 1996-07-09 | Southcorp Water Heaters Usa, Inc. | Balanced flue outdoor water heater |
| US6196164B1 (en) * | 1995-04-04 | 2001-03-06 | Srp 687 Pty. Ltd. | Ignition inhibiting gas water heater |
| US5697330A (en) * | 1995-04-04 | 1997-12-16 | Rheem Manufacturing Company | Power-vented, direct-vent water heater |
| US5797355A (en) * | 1995-04-04 | 1998-08-25 | Srp 687 Pty Ltd | Ignition inhibiting gas water heater |
| US5531214A (en) * | 1995-04-24 | 1996-07-02 | Cheek; Ricky L. | Gas vent and burner monitoring system |
| US6139311A (en) * | 1998-01-20 | 2000-10-31 | Gas Research Institute | Pilot burner apparatus and method for operating |
| US6142106A (en) * | 1998-08-21 | 2000-11-07 | Srp 687 Pty Ltd. | Air inlets for combustion chamber of water heater |
| US6058892A (en) * | 1998-08-26 | 2000-05-09 | Haack, Ii; Roger I. | Safety air flow control and routing apparatus for a water heater, water heater incorporating the apparatus, and method of using same |
| US5950573A (en) * | 1998-10-16 | 1999-09-14 | Srp 687 Pty. Ltd. | Power vented water heater with air inlet |
| US6035812A (en) * | 1998-11-02 | 2000-03-14 | The Water Heater Industry Joint Research And Development Consortium | Combustion air shutoff system for a fuel-fired heating appliance |
| US6109216A (en) * | 1999-07-22 | 2000-08-29 | Aos Holding Company | Flammable vapor resistant water heater |
| US20010042564A1 (en) * | 2000-04-12 | 2001-11-22 | Invensys Robertshaw Controls Company | Flammable vapor control system for devices with standing pilot flame |
| US6390028B1 (en) * | 2001-03-12 | 2002-05-21 | The Water Heater Industry Joint Research And Development Consortium | Fuel-fired liquid heating appliance with burner shut-off system |
-
2003
- 2003-10-09 US US10/681,227 patent/US20050079459A1/en not_active Abandoned
-
2004
- 2004-10-04 CA CA002483762A patent/CA2483762A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| US20050079459A1 (en) | 2005-04-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5391074A (en) | Atmospheric gas burner and control system | |
| CN1873343B (en) | Water heater with pressurized combustion and method for operaitng the same | |
| US6418883B2 (en) | Ignition inhibiting gas water heater | |
| US9228746B2 (en) | Heating device having a secondary safety circuit for a fuel line and method of operating the same | |
| US8454352B2 (en) | Micro-pilot for gas appliance | |
| US6973819B2 (en) | Differential compensated vapor sensor | |
| US6722876B2 (en) | Flammable vapor control system | |
| US6662757B2 (en) | Explosion proof gas-fired water heater | |
| US6295951B1 (en) | Ignition inhibiting gas water heater | |
| US20020134322A1 (en) | Gas fired appliance safety device | |
| US20190162411A1 (en) | Integrated gas igniter for solid fuel fire pit | |
| US6626133B2 (en) | Explosion protection sensor for gas appliances | |
| CN203024195U (en) | Gas appliance | |
| US20020134320A1 (en) | Ignition inhibiting gas water heater and controller | |
| US20050079459A1 (en) | Flammable vapour detector system for hot water heater | |
| US6074200A (en) | Burner apparatus having an air dam and mixer tube | |
| US4949705A (en) | Fireplace starting apparatus | |
| KR101627530B1 (en) | System and method for combusting vaporized flammable gas | |
| GB2612830A (en) | An air-gas mixture burning appliance with a variable ignition safety time | |
| KR101621829B1 (en) | Combustion device for vaporized flammable gas and combustion system thereof | |
| US6666174B1 (en) | Elevating base for gas-fired water heater | |
| KR101846858B1 (en) | Gas mixing apparatus and using gas range | |
| CN211553908U (en) | Air monitoring safety protection device of combustion fan heater | |
| US20060210937A1 (en) | Vapor resistant fuel burning appliance | |
| CN210832098U (en) | Gas stoves |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |