GB2330438A

GB2330438A - Gas heating apparatus

Info

Publication number: GB2330438A
Application number: GB9822288A
Authority: GB
Inventors: Robert Alan Charmer
Original assignee: Robinson Willey Ltd
Current assignee: Robinson Willey Ltd
Priority date: 1997-10-14
Filing date: 1998-10-14
Publication date: 1999-04-21
Anticipated expiration: 2018-10-14
Also published as: GB2330438B; GB9822288D0; GB9721654D0

Abstract

A gas-fired heating apparatus including a carbon monoxide sensing device 8 which operates such that on sensing an undesired level of carbon monoxide, the device generates an alarm signal (such as an audible alarm and/or a visible alarm, such as a light source) and/or enables the operation of or operates a flame failure device (4,5) or other gas cut-off means of the heating apparatus so as to cut-off the gas supply to the main burner thereof.

Description

GAS HEATING APPARATUS The present invention relates to gas fired heating apparatus such as a gas fire.

Electrically operated carbon monoxide sensors which may be deployed in rooms where gas fires are used, are known which emit an audible alarm when an undesirable level of carbon monoxide is detected and such are independent of the gas fire and separately functioning devices.

According to the present invention a gas-fired heating apparatus includes a carbon monoxide sensing device which operates such that on sensing an undesired level of carbon monoxide, the device generates an alarm signal (such as an audible alarm and/or a visible alarm, such as a light source) and/or operates a flame failure device or other gas cut-off means of the heating apparatus so as to cut-off the gas supply to the main burner thereof.

The sensing device preferably acts to cut-off the gas supply when the carbon monoxide sensing device senses the presence of carbon monoxide in quantities greater than such required to generate an initial alarm signal i.e. by the audible and/or visible alarm means. Thus a warning is given prior to cut-off.

The sensing device is preferably adapted such as to generate two signals, an initial one indicating a lower level of carbon monoxide and a subsequent one indicating a higher level of carbon monoxide and at which the device also acts to cut-off the gas supply.

It will be appreciated that the carbon monoxide sensing device is integral with or part of the gas-fired heating appliance and not a separately wall mountable device. It is of course possible for the sensing device to be mountable on a surface adjacent the apparatus or appliance but will be electrically connected thereto.

The heating apparatus or appliance will preferably include a thermocouple heatable by the main gas burner of the and/or pilot which maintains a flame failure device open whilst sensing the presence of heat and said carbon monoxide sensing device on sensing the presence of an undesirable amount of carbon monoxide operates to interrupt the current generated by the thermocouple with the result that the gas supply is cut-off.

Preferably the sensing device will be located at or towards the bottom of the heating apparatus thereby sensing the air being used by the fire and "pulled" by the effect of the chimney or flue.

It should be appreciated that the carbon monoxide sensing device of the present invention being incorporated in a gas-fired heating apparatus or appliance, such as a gas fire, will also act to emit an alarm signal when it senses the presence of carbon monoxide generated by other appliances in the same region. For example, if another appliance such as a cooker were emitting carbon monoxide, the sensing device will first generate a warning/alarm signal if lower levels of carbon monoxide are sensed before deactivating the gas heating apparatus.

The present invention is intended to be used in combination with an apparatus having a flame failure device and preferably with an ODS pilot-flame failure device.

It is of considerable advantage that the sensing and alarm device can be and is preferably powered by a battery. It may of course alternatively be mains powered.

The present invention may be used in combination with an apparatus including a catalytic converter and/or an oxygen depletion sensor (e.g. an ODS pilot jet) so as to break the thermocouple circuit when sensing carbon monoxide, and thus the alarm device provides an increased safety factor.

The apparatus of the present invention is preferably such that the gas supply to the burner and any pilot is closed on failure of the device or running down of the battery i.e. it is a fail-safe alarm system.

It is envisaged that the carbon monoxide sensing device may be replaced by another oxygen depletion sensing device or such may be used in combination with the carbon monoxide sensing device.

The present invention is particularly intended for domestic use and for tenanted property.

The present invention will normally include a device functioning as a carbon monoxide sensing and alarm device.

The invention will be described further, by way of example, with reference to the accompanying drawing which is a diagrammatic illustration of a gas-fired heating appliance including a gas sensing device.

A domestic gas fire 1 (not illustrated in detail) includes a pilot jet burner 2 in addition to a main gas burner (not shown) which is ignited by said pilot jet flame 3 ignited by ignition means (not shown). The pilot jet burner 2 may be an oxygen-depletion-sensing pilot light burner.

A thermocouple 4 is illustrated which is energised by heat from the flame 3 and is electrically connected to an electromagnetic valve 5 biassed into the normally closed position and acting as a flame failure device, which is located in the main gas supply pipe 6 to the main burner (not shown) and has a manual opening member 7. Once the valve 5 is opened by member 7 and an electric ignition device also energised to light pilot flame 3 and the main burner, the current from the thermocouple is such as to maintain the valve 5 open unless the pilot flame should go out in the event of a gas supply failure or lack of oxygen or other undesired situation or unless the circuit from the thermocouple 4 is deliberately broken when it is desired to turn the fire off or unless a carbon monoxide unit 8 operates to break the circuit as will now be described.

The carbon monoxide detector unit 8 forms part of the gas fire 1 and is located on a lower region of the fire 1 where air is flowing to the main gas burner and is connected in series is the circuit leading to and controlling the electromagnetic valve 5 so as to normally close such when no carbon monoxide is detected. Once carbon monoxide is detected by said unit 8, it operates such that the circuit to valve 5 is broken (as illustrated) and thus the valve 5 closes and the gas supply 6 to the appliance is cut-off.

The carbon monoxide electronic detector unit 8 is battery powered and the sensing part of such is well-known per se and need not be described further except to say that the unit is preferably adapted so as not only on operation to generate a signal so as to intercept the "hold-open'! signal from the thermocouple to the valve 5, but also to emit an audible and/or visible alarm. Preferably the unit initially operates to emit a first quieter or different audible and/or a visible alarm when it senses carbon monoxide at a lower level than when it emits a louder and/or different signal on detecting a level of carbon monoxide sufficient to require the gas fire to be turnedoff for safety.

The detector unit 8 may be detachably mounted on the gas fire 1 and have wires 8' of sufficient length from a thermocouple interrupter 4' as to enable the unit to be mounted on a surface, such as a wall, adjacent the gas fire, if desired and be of a nature as to permit such wall mounting. The interrupter 4' minimizes the impedance or length of wire from the thermocouple to the flame failure device.

Various modifications or embodiments may be made without departing from the scope of the invention. For example, the carbon monoxide device may be replaced by or supplemented with an oxygen-depletion-sensing device and preferably one which operates electrically. The sensing or sensor device may be additionally coupled to turn-off the gas supply to other gas appliances and/or even the supply to the dwelling - suitable electromagnetic valves being provided and connected - preferably with interrupters to minimize the impediance for the thermocouple circuit in normal operation.

Claims

CLAIMS 1. A gas-fired heating apparatus including a carbon monoxide sensing device which operates such that on sensing an undesired level of carbon monoxide, the device generates an alarm signal (such as an audible alarm and/or a visible alarm, such as a light source) and/or enables the operation of or operates a flame failure device or other gas cut-off means of the heating apparatus so as to cut-off the gas supply to the main burner thereof.
2. Apparatus as claimed in claim 1, in which the sensing device acts to enable or cause valve means to close and to cut-off the gas supply to the apparatus when the carbon monoxide sensing device senses the presence of carbon monoxide in undesirable quantities.
3. Apparatus as claimed in claim 2, which includes a thermocouple located to be energisable by the flame from a pilot light burner and/or from the flames of the main burner unit with said thermocouple being electrically connected to the flame failure device or other gas cut-off means in the gas supply to the burner which means acts to close the gas supply when the pilot flame and/or main burner flame is not present and the thermocouple is thus not energised and acts to close the gas supply when the carbon monoxide sensing device generates a signal to interrupt any signal from the thermocouple.
4. Apparatus as claimed in any of claims 1 to 3, in which the sensing device is such as to generate two signals, an initial signal indicating a lower level of carbon monoxide and a subsequent signal indicating a higher level of carbon monoxide and at which the device also acts to cause the gas supply to be cut-off.
5. Apparatus as claimed in any of claims 1 to 4, in which the sensing device is electrically powered and is dismountable from the apparatus and mountable on a surface adjacent the appliance whilst remaining electrically connected to the flame failure device or other gas cut-off means of the main burner
6. Apparatus as claimed in claim 1 or claim 2 or claims 4 and 5 when dependent on claim 1 or 2, in which a thermocouple is provided heatable by the flames of the main gas burner and/or by the flame of the pilot jet burner which maintains the flame failure device or other gas cutoff means open whilst sensing the presence of heat and said carbon monoxide sensing device on sensing the presence of an undesirable amount of carbon monoxide operates to interrupt the current generated by the thermocouple with the result that the gas supply is cut-off.
7. Apparatus as claimed in any of claims 1 to 6, in which is located at or towards the bottom of the heating apparatus and in a position such as to enable it to sense the air being used by the fire and "pulled" by the effect of the chimney or flue.
8. Apparatus as claimed in any of claims 1 to 7, including an oxygen-depletion-sensitive (ODS) pilot-flame failure device.
9. Apparatus as claimed in any of claims 1 to 8, in which the sensing and alarm device is powered by a battery.
10. Apparatus as claimed in any of claims 1 to 9, which includes a catalytic converter and/or an oxygen depletion sensor (e.g. an ODS pilot jet) and said sensing device operating so as to break the thermocouple circuit when sensing carbon monoxide, to thereby provide for an increased safety.
11. Apparatus as claimed in any of claims 1 to 10, in which control means are provided such that the gas supply to the burner and any pilot is closed on failure of the carbon monoxide sensing device or running down of the battery thereof.
12. Apparatus as claimed in any of claims 1 to 11, in which instead or in place of a carbon monoxide sensing device there is an oxygen-depletion-sensing device or the carbon monoxide sensing device is used in combination with an oxygen-depletion-sensing device.
13. Gas fired apparatus including a device functioning as a carbon monoxide sensing and alarm device.
14. A gas fired heating appliance including a carbon monoxide sensing device and/or an oxygen depletion sensing device substantially as herein described with reference to the accompanying drawing.
15. A carbon monoxide sensing device including an electrical switch means connectable to a circuit to open the circuit when the device senses carbon monoxide.
16. A carbon monoxide sensing device as claimed in claim 15, being an audible alarm means and/or a visible alarm means operable upon detection of carbon monoxide.
17. A carbon monoxide sensing device as claimed in claim 16, which is such as to generate different signals from the audible alarm means and/or the visible alarm means.
18. A carbon monoxide sensing device as claimed in claim 17, in which the device is such as to generate two signals - a first when a lower level of carbon monoxide is sensed and a second more noticeable signal when an unacceptable level of carbon monoxide is detected.