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Title:
FLUE-GAS ANALYSIS SAFETY APPARATUS
Document Type and Number:
WIPO Patent Application WO/2010/084296
Kind Code:
A2
Abstract:
Flue-gas analysis safety apparatus (10) for a gas or oil-fired device (30) having an electrical connection and a flue (54) for combustion gases, comprises a hazardous gas detection element (12) for placement in the flue (54) to monitor flue gas, and a controller (14) for automatically regulating a gas to air ratio in the flue gas based on a signal from the hazardous gas detection element (12). The controller (14) is able to halt a flow of electricity to the gas or oil-fired device (30) if the gas to air ratio in the flue gas cannot be regulated to fall within a predetermined safe parameter. Preferably, the hazardous gas detection element (12) includes a wireless transmitter, and the controller (14) includes a wireless receiver so that the hazardous gas detection element (12) is wirelessly communicable with the controller (14). A gas or oil-fired device having the apparatus (10), and a method are also provided.

Inventors:
RICHARDSON, Callum, Scott, Stewart (37 Gunsgreen Crescent, Eyemouth, Berwickshire TD14 5DW, GB)
CRAWFORD, Richard, James (Lindenlea, Windyknowe RoadGalashiels, Selkirkshire TD1 1RF, GB)
Application Number:
GB2009/001808
Publication Date:
July 29, 2010
Filing Date:
July 22, 2009
Export Citation:
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Assignee:
RICHARDSON, Callum, Scott, Stewart (37 Gunsgreen Crescent, Eyemouth, Berwickshire TD14 5DW, GB)
CRAWFORD, Richard, James (Lindenlea, Windyknowe RoadGalashiels, Selkirkshire TD1 1RF, GB)
International Classes:
F23N5/00
Foreign References:
US20070227125A12007-10-04
EP1980789A22008-10-15
GB2372130A2002-08-14
US5793296A1998-08-11
Attorney, Agent or Firm:
ALBRIGHT PATENTS (Eagle Tower, Montpellier Drive, Cheltenham GL50 1TA, GB)
Download PDF:
Claims:
Claims

1. Flue-gas analysis safety apparatus for a gas or oil-fired device having an electrical connection and a flue for combustion gases, the apparatus comprising a hazardous gas detection element for placement in the flue to monitor flue gas, and a controller for automatically regulating a gas to air ratio in the flue gas based on a signal from the hazardous gas detection element, the controller being able to halt a flow of electricity to the gas or oil-fired device if the gas to air ratio in the flue gas cannot be regulated to fall within a predetermined safe parameter.

2. Flue-gas analysis safety apparatus as claimed in claim 1, wherein the hazardous gas detection element includes a wireless transmitter, and the controller includes a wireless receiver so that the hazardous gas detection element is wirelessly communicable with the controller.

3. Flue-gas analysis safety apparatus as claimed in claim 1 or claim 2, wherein the hazardous gas detection element includes an elongate wand having a hazardous gas sensor at a distal end.

4. Flue-gas analysis safety apparatus as claimed in claim 3, wherein the wand is flexibly adjustable.

5. Flue-gas analysis safety apparatus as claimed in any one of the preceding claims, wherein the controller includes a warning element for outputting a warning signal when regulating a gas to air ratio.

6. Flue-gas analysis safety apparatus as claimed in any one of the preceding claims, wherein the controller includes a warning element for outputting a warning signal on disconnection from the hazardous gas detection element.

7. Flue-gas analysis safety apparatus as claimed in any one of the preceding claims, further comprising a remote hazardous gas detection device for placement remotely from the gas or oil-fired device for outputting a warning signal on detection of hazardous gas.

8. Flue-gas analysis safety apparatus as claimed in claim 7, wherein the remote hazardous gas detection device is communicable with the controller to halt a flow of electricity to the gas or oil-fired device.

9. Flue-gas analysis safety apparatus as claimed in claim 7 or claim 8, wherein the remote hazardous gas detection device includes a wireless transmitter and receiver for transmitting a signal to the controller to halt the gas or oil-fired device and for receiving a signal from the controller and/or the hazardous gas detection element to output the warning signal.

10. Flue-gas analysis safety apparatus as claimed in any one of the preceding claims, wherein the controller includes a warning element for outputting a warning signal on receiving a signal from the remote hazardous gas detection device.

11. Flue-gas analysis safety apparatus as claimed in any one of the preceding claims, wherein the controller includes an independent removable housing which has a socket for receiving an electrical plug of a gas or oil-fired device and prongs for insertion into an electrical socket.

12. Flue-gas analysis safety apparatus as claimed in any one of claims 1 to 10, wherein the controller comprises a non-removable surface-mountable housing which is directly connectable to a mains electricity power supply, the housing including a socket for receiving an electrical plug of a gas or oil-fired device.

13. Flue-gas analysis safety apparatus as claimed in any one of claims 1 to 10, wherein the controller is provided on-board as part of the gas or oil-fired device.

14. Flue-gas analysis safety apparatus as claimed in any one of the preceding claims, wherein the hazardous gas detection element can detect at least carbon monoxide.

15. Flue-gas analysis safety apparatus substantially as hereinbefore described with reference to the accompanying drawings.

16. A gas or oil-fired device having an electrical connection, the device having a flue for combustion gases in which is provided the hazardous gas detection element of the flue-gas analysis safety apparatus as claimed in any one of the preceding claims, the gas to air ratio in the flue gas and the electrical connection of the device being automatically controllable by the said controller based on an output of the hazardous gas detection element.

17. A gas or oil-fired device as claimed in claim 16, wherein the device is a boiler. 18. A method of preventing or limiting hazardous gas exposure from a defective gas or oil-fired device having an electrical connection, by using flue-gas analysis safety apparatus as claimed in any one of claims 1 to 15, the method comprising the steps of : a) providing the hazardous gas detection element in a flue of the gas or oil-fired device; and b) automatically regulating a gas to air ratio in the flue gas based on a signal from the hazardous gas detection element so as to fall within a predetermined safe parameter, and halting the electricity supply to the gas or oil-fired device thereby shutting down the said device if the predetermined safe parameter cannot be attained.

Description:
Flue-Gas Analysis Safety Apparatus

The present invention relates to flue-gas analysis safety apparatus, to a gas or oil-fired boiler having an electrical connection and incorporating the said apparatus, and to a method of preventing or limiting carbon monoxide or other hazardous gas exposure from a defective gas or oil-fired boiler assembly having an electrical connection by using said apparatus.

Leakage of carbon monoxide or carbon dioxide from a cracked, damaged or incorrectly installed flue is hazardous and can result in death. Standalone carbon monoxide alarms are widely available, but are only activated once substantial leakage into the area of the alarm has already occurred. Inefficient or damaged boilers can produce dangerous levels of carbon monoxide or other hazardous gases which are vented via the flue over extended periods, and even years, without being noticed. When the flue then becomes damaged or blocked, the flue gases with dangerous levels of carbon monoxide or other gases are vented to the interior of the building causing a serious hazard.

The present invention seeks to provide a solution to these problems whereby carbon monoxide or other hazardous gases produced by a boiler is/are monitored and controlled before leakage to the interior of the building occurs.

According to a first aspect of the invention, there is provided flue-gas analysis safety apparatus for a gas or oil-fired device having an electrical connection and a flue for combustion gases, the apparatus comprising a hazardous gas detection element for placement in the flue to monitor flue gas, and a controller for automatically regulating a gas to air ratio in the flue gas based on a signal from the hazardous gas detection element, the controller being able to halt a flow of electricity to the gas or oil-fired device if the gas to air ratio in the flue gas cannot be regulated to fall within a predetermined safe parameter.

Preferable and/or optional features of the first aspect of the invention are set forth in claims 2 to 14, inclusive. According to a second aspect of the invention, there is provided a gas or oil-fired device having an electrical connection, the device having a flue for combustion gases in which is provided the hazardous gas detection element of the flue-gas analysis safety apparatus in accordance with the first aspect of the invention, the gas to air ratio in the flue gas and the electrical connection of the device being automatically controllable by the said controller based on an output of the hazardous gas detection element.

According to a third aspect of the invention, there is provided a method of preventing or limiting hazardous gas exposure from a defective gas or oil-fired device having an electrical connection, by using flue-gas analysis safety apparatus in accordance with the first aspect of the invention, the method comprising the steps of : a) providing the hazardous gas detection element in a flue of the gas or oil-fired device; and b) automatically regulating a gas to air ratio in the flue gas based on a signal from the hazardous gas detection element so as to fall within a predetermined safe parameter, and halting the electricity supply to the gas or oil-fired device thereby shutting down the said device if the predetermined safe parameter cannot be attained.

The invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which :

Figure 1 shows a first embodiment of flue-gas analysis safety apparatus, in accordance with the first aspect of the invention;

Figures 2 to 4 show the flue-gas analysis safety apparatus when in use;

Figure 5 shows a front elevational view of a controller of the flue-gas analysis safety apparatus, again when in use;

Figure 6 shows part of a second embodiment of flue-gas analysis safety apparatus; and

Figure 7 shows part of a third embodiment of flue-gas analysis safety apparatus.

Referring firstly to Figures 1 to 5 of the drawings, there is shown a first embodiment of flue-gas analysis safety apparatus 10 which comprises a, preferably at least carbon monoxide, gas detection element 12, a controller 14, and a remote carbon monoxide detection device 16. The detection element 12 in this embodiment comprises an elongate flexible wand 18, a preferably at least carbon monoxide sensor 20 provided at a distal end of the wand 18, and a slim housing 22 at a proximal end of the wand 18. A battery compartment and wireless transmitter are provided in the slim housing 22. Preferably, batteries are used to power the sensor 20 and the transmitter. However, additionally or alternatively, the detection element 12 may be connectable to a mains power supply.

The detection element 12 is liquid-resistant and heat-resistant, due to its intended placement in the boiler's flue.

The controller 14 is separate of and spaced from the detection element 12, and comprises a, typically moulded plastics, controller housing 24 having a plug socket 26 on one side for receiving an electrical plug 28 of the boiler 30, and electrical prongs 32 on another side for removable engagement with a wall-mounted electricity supply socket 34. A wireless receiver for receiving a signal from the detection element transmitter is provided within the controller housing 24, along with control circuitry for controlling a supply of electricity to the electrical plug 28 of the boiler 30. A wireless transmitter is also provided for communicating with a controller on the gas or oil-fired device which includes at least an electronically adjustable air regulation valve and preferably also an electronically adjustable gas regulation valve. The control circuitry of the controller 14 automatically controls a gas to air ratio in the flue gas via the controller and valve or valves of the gas or oil-fired device based on feedback from the detection element so that a safe ratio falling within a predetermined parameter is sought.

The controller 14 of the apparatus 10 also includes a warning circuit which is electrically connected to the control circuit. The warning circuit includes an output device 36, which in this case is a speaker 38 for outputting an audible warning signal and a light emitting element 40, such as an LED, on the controller housing 24 for outputting a visual signal. In the present case, three said light emitting elements 40 are provided as part of the warning circuit. The first light emitting element 42 shows a status of the detection element 12, and will change if, for example, an electrical supply to the detection element 12 fails. In this case, the speaker 38 also emits a first audible warning signal.

The second light emitting element 44 changes if the presence of carbon monoxide above a predetermined level is detected by the detection element 12. Again, the speaker 38 also emits a second audible warning signal, preferably being different to the first audible warning signal.

The third light emitting element 46 displays a status of the remote carbon monoxide detection device 16. If an electrical supply to the remote detection device 16 fails or if the remote detection device 16 detects carbon monoxide above a predetermined level, then the display colour changes. In this case, the speaker 38 also emits a third audible warning signal, which is preferably different to those of the first and second signals.

The remote carbon monoxide detection device 16 comprises a, typically moulded plastics, device housing 48 having a battery compartment, a wireless transmitter and receiver, a carbon monoxide sensor circuit, and a warning circuit. The transmitter and receiver allow wireless communication with the controller 14 and, preferably also, the detection element 12. The warning circuit preferably includes a speaker 50 for outputting an audible warning signal to alert an occupant of the room and/or building. The warning circuit may also include a light emitting element 52, again, such as an LED, for outputting a visual signal showing the status of the remote detection device 16. Although the remote detection device 16 is preferably battery operated, it may be additionally or alternatively connected to a mains electricity power supply.

In use and with reference to Figure 2 to 4, the wireless remote detection element 12 is slid into the flue 54 of a gas or oil-fired boiler 30. Typically, the flue 54 includes a horizontal portion 56 which discharges to the outside 58. The exit is usually covered by a grating or grill 60. By removing the grill 60, the wireless detection element 12 can be easily slid into the flue 54 so that the sensor 20 is facing away from the exit and upstream. The grill 60 is then replaced. The controller 14 is then plugged into a wall socket 34 adjacent to the boiler 30, and the boiler plug 28 is plugged into the socket 26 of the controller housing 24. The controller 14 is preferably mains powered, but may additionally by battery powered.

The remote detection device 16 is attached to a surface which is preferably adjacent to the boiler 30, either being a wall or ceiling 62.

Once operational, the detection element 12 continuously monitors a level of carbon monoxide and/or other hazardous gas in the combustion gas discharged from the boiler 30 and along the flue 54. The remote detection device 16 also continuously monitors a level of carbon monoxide in the room in which it is located.

If the detection element 12 senses a level of carbon monoxide which exceeds a predetermined limit or ratio, it sends a signal to the controller 14. The warning circuit changes the second light emitting element 44 to output a visual alert, and the speaker 38 is activated to output an audible alert. The control circuitry simultaneously automatically remotely controls the controller of the boiler 30 to regulate the gas to air ratio of the flue gas to bring it back to within a predetermined safe parameter. After a predetermined period dictated by an onboard timer on the controller 14 and feedback from the detection element 12, if this cannot be achieved, then the controller halts a flow of current to the housing socket 26, thereby shutting off or disabling the boiler 30. Once the level of carbon monoxide reduces to below the predetermined limit, a signal is outputted from the detection element 12 causing the controller 14 to reset. Consequently, the boiler 30 can be reignited following servicing and/or repair.

The signal outputted by the detection element 12 is also receivable by the remote detection device 16, which in turn outputs a warning signal. The remote detection device 16 is also reset following a drop in the level of carbon monoxide detected by the detection element 12.

If the remote detection device 16 itself first senses carbon monoxide which exceeds a predetermined limit, then it outputs an audible alert and a signal via its transmitter to the controller 14, causing the air to gas ratio in the flue gas to be automatically regulated to a safe level and, failing that, disabling the boiler 30 as described above. In this case, the warning circuit changes the visual appearance of the third light emitting element 46 on the controller housing 24.

Referring to Figure 6, there is shown a second embodiment of flue-gas analysis safety apparatus 10. Like references refer to parts which are similar to those of the first embodiment, and further detailed description is omitted.

In this embodiment, the detection element 12 and the remote detection device 16 are identical. However, the controller 14 is not removable. In this case, the controller 14 is directly electrically connected to a mains electricity supply. The gas or oil-fired boiler 30 may either be directly and non-removably electrically connected to the controller 14, or may be plugged in as in the first embodiment.

The other features remain the same those described in the first embodiment.

Referring to Figure 7, there is shown a third embodiment of flue-gas analysis safety apparatus 10. Like references refer to parts which are similar to those of the first embodiment, and further detailed description is again omitted.

In this embodiment, the detection element 12 and the remote detection device 16 are again as described in the first embodiment. However, the controller 14 is on-board and fully integrated as part of the gas or oil-fired boiler 30 itself, simplifying automatic regulation and disabling and dispensing with the need for a transmitter on the controller as in the pevious embodiments. In this case, the controller housing 24 forms part of the boiler housing 64, and typically the control circuit and the warning circuit are provided as part of the electronic circuitry of the boiler 30 itself.

The boiler 30 is therefore plugged or connected to an electricity supply in its normal way, but on detection of carbon monoxide and/or other hazardous gas in excess of a predetermined limit, the control circuit automatically regulates to bring about a safe ratio and, failing this after a period, halts the flow of electricity to the boiler circuit, thus shutting down the boiler 30. Although particularly applicable to gas or oil-fired boilers, the flue-gas analysis safety apparatus can potentially be applied to any gas or oil-fired device having a flue, such as a fire.

If a power supply of the detection element 12 or the remote detection device 16 is interrupted or stopped, for example, by batteries running down, a signal being outputted by the detection element 12 or the remote detection device 16 stops and thus the warning circuit of the controller 14 outputs an audible alert and changes the visual appearance of the first light emitting element 42.

The detection element, remote detection device and/or controller may all include a test function including a test button for periodic testing of the apparatus.

The detection element may not require the wand 18. However, the wand, preferably being flexibly adjustable, is advantageous in that the sensor 20 can be placed closer to the entrance of the flue from the boiler body without the detection element falling into the interior of the boiler body.

Although the detection element is shown as lying on a bottom surface of the flue, it may include a clip or other means by which it can be held spaced from the bottom surface to prevent contact with condensate.

To enable the controller, detection element and remote detection device to communicate with each other, any suitable wireless data protocol or means can be utilised, such as Wi-Fi, Bluetooth RTM, radio or microwave.

Although preferably wireless, the controller, detection element and remote detection device may be hard wired to each other.

One, more or all of the light emitting elements of the warning circuit may include a pre- warning alert on detection of a hazardous gas or a change in the ratio of gases within the flue. The pre-warning alert may comprise a further different colour and/or sound. For example, when the flue gases are within a predetermined tolerance or parameter, a green visual signal is emitted and there is no sound. The pre-warning signal may, for example, be an orange visual signal and an intermittent sound. The full alert may be, for example, a red visual alert and a continuous sound.

The remote detection device is preferable, and may be dispensed with dependent on necessity. Alternatively, two or more remote detection devices can be utilised. In this case, the remote detection devices are preferably in communication with each other, the detection element, and/or the controller. The or each remote detection device may be in the same room as the boiler, or any suitable room, such as a bedroom or living space.

Although the detection of carbon monoxide is preferable, the detection element and the remote detection device(s) may additionally or alternatively detect another gas or other gases, preferably being hazardous, such as carbon dioxide. Ratios or changes in ratios of constituent gases within the flue may instead or additionally be monitored by the detection element.

The distal end of the wand may include a filter element for the or each detectable flue gas. In this case, the filter element may be replaceable and/or interchangeable, typically during a service.

Although the detection element is preerably wireless, it may be in wired connection with the controller.

It is thus possible to provide flue-gas analysis safety apparatus which immediately alerts an occupant or user of the gas or oil-fired device to carbon monoxide or other hazardous gas exceeding a predetermined level in the flue. It is also possible to provide flue-gas analysis safety apparatus which automatically regulates an air to gas ratio to try to attain a safe parameter, and then failing this immediately shuts down or disables the boiler in the presence of carbon monoxide or other hazardous gas which exceeds a predetermined level for a predetermined period. The controller of the apparatus can be a plug in device, thus enabling quick and simple retrofitting to existing boilers, a permanently fixed device which is remote from the boiler, or integrated as part of the boiler. The sensor is preferably in wireless communication with the controller, and can thus be easily located in the flue. The apparatus thus reduces the chance of having a gas or oil-fired device which is malfunctioning over any extended period, thus potentially saving the lives of the users. The apparatus can also reduce operating costs of the gas or oil-fired device by highlighting potential defects, and furthermore reduce the environmental impact of a malfunctioning gas or oil-fired device.

The embodiments described above are provided by way of examples only, and various other modifications will be apparent to persons skilled in the art without departing from the scope of the invention as defined by the appended claims.