GB2623332A

GB2623332A - Solid fuel appliance

Info

Publication number: GB2623332A
Application number: GB2215053.6A
Authority: GB
Inventors: Kingscott Ian; Coke Michael
Original assignee: Stovax Ltd
Current assignee: Stovax Ltd
Priority date: 2022-10-12
Filing date: 2022-10-12
Publication date: 2024-04-17
Also published as: GB202215053D0

Abstract

A solid fuel combustion appliance 101 is operable in a conventional burn mode and a reverse burn mode. Flue gas from combustion of solid fuel in either mode is exhausted through a catalytic converter 302. The appliance may be a natural draft wood burning stove. The appliance may have a combustion chamber (102, Fig. 1) comprising a main chamber 201 receiving solid fuel and which is in fluid communication with an ancillary chamber 202. An air intake 301 may allow air into the combustion chamber. A flow control mechanism 303 may direct gas from the main chamber or from the ancillary chamber, into a flue 103 containing the catalytic converter. A bed 304 may provide a pathway 305 between the main chamber and the ancillary chamber. The appliance may be switched from a first period of conventional combustion to a second period of reverse-burn combustion when a temperature in the combustion chamber exceeds a threshold. An air intake channel 312 may be located between the main chamber and a portion 310 of the ancillary chamber. The air intake may be connected to an external air supply duct by a connector 303.

Description

SOLID FUEL APPLIANCE

Field of the Invention

The present invention relates to a solid fuel appliance, and more particularly to a solid fuel appliance operable to burn a solid fuel in a reverse burn mode.

Background of the Invention

Solid fuel appliances are known for burning a solid fuel, such as coal, wood, or peat, to produce heat, which may be used for cooking, to provide hot water, or to provide space heating. Type of solid fuel appliance include wood burning stoves, which feature a bed upon which logs can be burnt, and multi fuel stoves, which feature a grate upon which logs or other materials, such as coke, or anthracite, may be burnt A solid fuel appliance intended for use in an industrial setting may be designed with emphasis predominantly on performance, whereas a solid fuel appliance for use in a domestic environment may be designed with more consideration given to decorative appearance.

Traditionally, solid fuel appliances work on a natural draught principle. During combustion, air within the combustion chamber is heated, leading it to rise and escape through a flue; this flow of heated air causes combustion gases to be evacuated for safe exhaust to open air.

Solid fuel appliances for burning renewable or biomass fuels, for example wood chips, are perceived as offering environmental benefits, for example, it has been recognised that while trees release carbon dioxide into the atmosphere when felled and burnt, trees absorb and store carbon dioxide from the atmosphere when growing. Studies are ongoing not only to investigate an extent of offsetting of carbon dioxide that can be identified from growing trees for fuel, but also which species and growing conditions and methods are most effective for this commercial sector.

It is desirable to improve combustion efficiency and to reduce the release of potentially harmful combustion products into the atmosphere.

Technological advances have resulted in the provision of solid fuel appliances operable to effect combustion of a solid fuel using "reverse burn" in which the flue gas do not escape through the flue directly but are forced down through the grate first. The downward flow of flue gas, against the natural inclination to rise upwards, is achieved with the assistance of a fan arrangement. Examples of this technology are mostly found in utility type biomass batch boilers.

The present disclosure relates to the provision of improvements in relation to a solid fuel appliance operable to burn a solid fuel in a reverse burn mode.

Summary of the Invention

According to a first aspect there is provided a solid fuel appliance, the solid fuel appliance operable in a conventional burn mode and in a reverse-burn mode, the solid fuel appliance comprising a catalytic converter through which flue gas from combustion of a solid fuel in either of the conventional burn mode and the reverse-burn mode is exhausted.

Thus, the solid fuel appliance is operable in a conventional burn mode and in a reverse-burn mode, and flue gas from combustion of a solid fuel in either of the conventional burn mode and the reverse-burn mode is exhausted through the catalytic converter, which is functional to remove pollutants from the flue gas.

In an embodiment, the solid fuel appliance is a natural draft stove.

In an application, the solid fuel appliance is for burning wood.

In an example, the solid fuel appliance comprises a combustion chamber, comprising: a main chamber for receiving a solid fuel to be combusted, and an ancillary chamber, in communication with the main chamber, an air intake arrangement for permitting air to be admitted into the combustion chamber; a flue, for permitting flue gas to be exhausted from the combustion chamber, a catalytic converter, and a flow control mechanism, operable to direct flue gas to be exhausted from: the main chamber, along a first exhaust flow path passing through the catalytic converter, or the ancillary chamber, along a second exhaust flow path passing through the catalytic converter.

In an example, the flow control mechanism is operable to: during a first period of combustion, direct flue gas to be exhausted from the main chamber, and during a second period of combustion, direct flue gas to be exhausted from the ancillary chamber.

Thus, during the conventional burn mode, flue gas can be exhausted along a flow path from the main chamber, through the catalytic converter, and through the flue, and during the reverse-burn mode, flue gas is exhausted along a different flow path from the main chamber, through the ancillary chamber, through the catalytic converter, and through the flue. Hence, gas is exhausted to the flue from the main chamber during the conventional burn mode and from the ancillary chamber during the reverse-burn mode.

The first period of combustion may be an initial period of conventional combustion and the second period of combustion a subsequent period of reverse-burn combustion.

The solid fuel appliance may comprise a flow control mechanism switch arrangement operable to cause the flow control mechanism to switch from directing flue gas to be exhausted from the main chamber and directing flue gas to be exhausted from the ancillary chamber.

In an example, the flow control mechanism switch arrangement comprises a temperature detection arrangement configured for detecting when a temperature in the combustion chamber has exceeded a threshold temperature, and wherein commencement of the subsequent period of combustion is on detection of a temperature in the combustion chamber exceeding the threshold temperature.

The flow control mechanism switch arrangement may comprise a manually operable element configured for allowing a user to selectively cause the flow control mechanism to switch from directing flue gas to be exhausted from the main chamber to directing flue gas to be exhausted from the ancillary chamber.

In an example, a bed provides the ancillary chamber in communication with the main chamber, the bed defining a pathway for allowing a passage of gas therethrough.

The pathway may allow the passage of: air into the main chamber when the flow control mechanism is directing flue gas to be exhausted from the main chamber, and flue gas from the main chamber into the ancillary chamber when the flow control mechanism is directing flue gas to be exhausted from the ancillary chamber.

In an example, a first portion of the ancillary chamber extends below the main chamber and a second portion of the ancillary chamber extends behind the main chamber, substantially perpendicularly to the first portion.

An air intake channel may be disposed behind the main chamber and in front of the second portion of the ancillary channel.

The solid fuel appliance may comprise a door for providing access into the combustion chamber, which may be common to the main chamber and the ancillary chamber.

In an example, the catalytic converter is removable.

The catalytic converter may be disposed within a flue spigot The air intake arrangement may be provided with a direct air supply connection arrangement for connecting the air intake to an external direct air supply duct Further particular and preferred aspects of the invention are set out in the accompanying dependent claims.

Brief Description of the Drawings

The present invention will now be more particularly described, with reference to the accompanying drawings, in which: Figure I shows a perspective view of a solid fuel appliance, in a closed condition; Figure 2 shows a perspective view of the solid fuel appliance of Figure I, in an open condition; Figure 3 shows a schematic of the solid fuel appliance of Figure I; Figure 4 shows a cutaway view of the solid fuel appliance of Figure I, with flow characteristics of a conventional burn mode indicated; and Figure 5 shows a cutaway view of the solid fuel appliance of Figure I, with flow characteristics of a reverse-burn burn mode indicated.

Description

Illustrative embodiments and examples are described below in sufficient detail to enable those of ordinary skill in the art to embody and implement the apparatus described herein. It is to be understood that embodiments and examples can be provided in many alternate forms and the invention should not be construed as limited to the embodiments and examples set forth herein but by the scope of the appended claims.

Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be interpreted as is customary in the art. In addition, features referred to herein in the singular can number one or more, unless the context clearly indicates otherwise.

Similarly, the terms "comprises", "comprising", "includes", "including", "has" and/or "having" when used herein, specify the presence of the stated feature or features and do not preclude the presence or addition of one or more other features, unless the context clearly indicates otherwise.

In the following description, all orientational terms, such as upper, lower, radially and axially, are used in relation to the drawings and should not be interpreted as limiting on the invention, unless the context clearly indicates otherwise.

The drawings are not necessarily drawn to scale, and in some instances the drawings may have been exaggerated or simplified for illustrative purposes only.

Features of a solid fuel appliance according to the present invention will now be described with reference to the accompanying Figures.

A solid fuel appliance 101 is shown in Figures 1 & 2. According to an example, the solid fuel appliance 101 is for burning wood. According to an example, the solid fuel appliance 101 is a natural draft stove.

According to this illustrated example, the solid fuel appliance 101 is a natural draft, wood burning stove.

The solid fuel appliance 101 comprises a combustion chamber, indicated at 102, in which a solid fuel is combustible, and a flue, indicated at 103, for permitting flue gas to be exhausted from the combustion chamber 102.

The solid fuel appliance 101 comprising a housing 104 provided with a door 105, the door 104 for allowing access into the combustion chamber 102, the access allowing a solid fuel to be placed in the combustion chamber 102 for burning. The access also allows cleaning and maintenance. The door 105 comprises a viewing panel 106. The viewing panel 106 allows a user to see into the combustion chamber 102.

The housing 104 may be fabricated from any suitable material or combination of materials.

The solid fuel appliance 101 is shown in Figure I with the door 105 closed and in Figure 2 with the door 105 open. A schematic of the solid fuel appliance 101 is shown in Figure 3.

The combustion chamber 102 comprises a main chamber 201, for receiving a solid fuel to be combusted, and an ancillary chamber 202. The ancillary chamber 202 is in communication with the main chamber 201.

The solid fuel appliance 101 comprises an air intake arrangement, indicated generally at 301, for permitting air to be admitted into the combustion chamber 102, more particularly into the main chamber 201.

According to this illustrated example, the door 105 is common to both the main chamber 201 and the ancillary chamber 202. Opening the door 105 provides access to both the main chamber 201 and the ancillary chamber 202 simultaneously and closing the door 105 shuts both at the same time.

According to this illustrated example, the viewing panel 106 of door 105 is provided for allowing a user to see into the main chamber 201 and a further viewing panel 203 is provided for allowing a user to see into the ancillary chamber 202. It is to be appreciated that other arrangements are possible.

The door 105 is also provided with a handle 204 for facilitating opening and closing of the door 105. In this illustrated example, the handle 204 is associated with a locking mechanism suitable for allowing a user to unlock the door 105 for opening and lock the door 105 after closing, the handle 204 enables quick and convenient operation of the associated door 105, negating the requirement for any tool or tools to be utilised; appropriate personal protective equipment, for example a glove, should however still be used.

In an example, the handle extends substantially vertically and substantially flush with a side of the solid fuel appliance when in a position associated with the door being closed and latched. The handle is pivotable from this position, in a first direction of rotation about a pivot axis, by the manual application of a pushing force against an upper region of the handle, causing a lower edge of the handle to be raised far enough for fingers of a hand to be located behind the handle. The motion of raising the handle further will unlatch the door; the handle can be lifted until a stop feature inhibits further movement but still provides enough clearance for comfortable use. With the door unlatched, it can be swung open in a first direction of rotation about a hinge axis. The door can then be closed by being swung in a second, opposite direction of rotation about the hinge axis, with the handle still in the lifted position, and then the handle pivoted down into the initial position, in a second, opposite direction of rotation about a pivot axis, flush with the side of the solid fuel appliance, this motion causing the door to be again latched.

As can be seen in particular in Figure 2, a guard panel 205 is provided for retaining a solid fuel, such as logs, within the main chamber 201. The guard panel may comprise any suitable material or combination of materials. In an example, the guard panel comprises ceramic glass.

According to this example also, the housing 104 is provided with a pair of side, viewing panels, 206, 207 allowing a user to see into the combustion chamber 102, more particularly the main chamber 201, from either side of the solid fuel appliance 101.

The solid fuel appliance may comprise any suitable number of viewing panels, in any suitable arrangement. The or each viewing panel may comprise any suitable material or combination of materials. In an example, the or each viewing panel comprises ceramic glass.

The main chamber 201 and ancillary chamber 202 may be lined with any suitable material, for example vermiculite.

According to this illustrated example, the housing 104 is provided with an airwash vent 208, disposed above the opening that is revealed when the door 105 is opened. The airwash vent 208 is in communication with the air intake arrangement 301. Further, a vent plate 209 is provided at an upper region of the main chamber 201, through which can air enter the main chamber 201 from the air intake arrangement 301.

In this illustrated example, the housing 104 is arranged on a plinth 210. The plinth 210 may be fabricated from any suitable material or combination of materials.

The solid fuel appliance 101 further comprises a catalytic converter 302, and a flow control mechanism, indicated generally at 303. The catalytic converter may comprise a 25mm thick catalyst.

According to this illustrated example, a bed 304 provides the ancillary chamber 201 in communication with the main chamber 201, the bed 304 defining a pathway, indicated at 305, for allowing a passage of gas therethrough.

In the present example, air may enter the main chamber 201 through the pathway 305 of the bed 304. The bed 304 may be a multi-casting assembly for providing precision air flow.

According to this illustrated example, the flow control mechanism 303 comprises a closure device 306, that is movable to selectively open and close an aperture, indicated at 307, of the main chamber 201, to permit or prevent exhaust of flue gas therethrough. According to the specific illustrated example, the closure device 307 is a bypass flap.

As will be described further, the solid fuel appliance 101 is operable in a conventional burn mode and in a reverse-burn mode, and flue gas from combustion of a solid fuel in either of the conventional burn mode and the reverse-burn mode is exhausted through the catalytic converter 302. The catalytic converter 302 is functional to remove pollutants from the flue gas.

The solid fuel application 101 is shown in Figure 4 with flow characteristics of a conventional burn mode indicated and in Figure 5 with flow characteristics of a reverse-burn mode indicated.

As will be detailed further, the flow control mechanism 303 is operable to direct flue gas to be exhausted from the main chamber 201 along a first exhaust flow path passing through the catalytic converter 302, or from the ancillary chamber 202 along a second exhaust flow path passing through the catalytic converter 302.

The catalytic converter 302 is arranged within the solid fuel appliance 101 such that the flue gas passes therethrough before exiting the flue 103.

During the conventional burn mode, flue gas is exhausted along a flow path from the main chamber 201, through the aperture 307 of the main chamber 201, through the catalytic converter 302, and through the flue 103. During the reverse-burn mode, flue gas is exhausted along a different flow path from the main chamber 201, through the bed 304, through the ancillary chamber 202, through the catalytic converter 302, and through the flue 103. Thus, flue gas is exhausted to the flue 103 from the main chamber 201 during the conventional burn mode and from the ancillary chamber 202 during the reverse-burn mode.

The flow control mechanism 303 is operable to, during a first period of combustion, direct flue gas to be exhausted from the main chamber 201, and during a second period of combustion, direct flue gas to be exhausted from the ancillary chamber 202.

Commencement of the subsequent period of combustion may be on detection of a temperature in the combustion chamber exceeding a threshold temperature.

The flow control mechanism 303 is operable to direct flue gas to be exhausted from the main chamber 201, through the catalytic converter 301, during a first period of combustion that is an initial period of conventional combustion, and to direct flue gas to be exhausted from the ancillary chamber 202, through the catalytic converter 301, during a second period of combustion that is a subsequent period of reverse-burn combustion.

Initially, the closure device 306 of the flow control mechanism 303 is open. When combustion commences, air is drawn into the combustion chamber 102. Air can enter the main chamber 201, from the air intake arrangement 301, through the bed 304, airwash vent 208 and vent plate 209. Flue gas is exhausted to the flue 103 from the main chamber 201, through the aperture 307. The flue gas passes through the catalytic converter 301.

When a suitable temperature for reverse-burn is reached, the closure device 306 of the flow control mechanism 303 is closed. Air can still enter the main chamber 201, from the air intake arrangement 301; however, flue gas is exhausted to the flue 103 from the ancillary chamber 202, passing first through the bed 304. The flue gas passes through the catalytic converter 301.

Thus, the pathway 305 of the bed 304 allows the passage of air into the main chamber 201 when the flow control mechanism 303 is directing flue gas to be exhausted from the main chamber 201 and allows the passage of flue gas from the main chamber 201 into the ancillary chamber202 when the flow control mechanism 303 is directing flue gas to be exhausted from the ancillary chamber 202.

In an example, the solid fuel appliance 101 comprises a flow control mechanism switch arrangement 308 comprising a temperature detection arrangement configured for detecting when at least when a temperature in the combustion chamber 102, more particularly in the main chamber 201, risen to or above a threshold temperature On detecting that the threshold temperature has been exceeded, the flow control mechanism switch arrangement can cause the flow control mechanism 303 to switch from directing flue gas to be exhausted from the main chamber 201 to directing flue gas to be exhausted from the ancillary chamber 202.

In an example, the temperature detection arrangement is further configured for detecting when a temperature in the combustion chamber 102, more particularly in the main chamber 201, has dropped to or below the threshold temperature. On detecting that the threshold temperature is no longer exceeded, the flow control mechanism switch arrangement can cause the flow control mechanism 303 to switch from directing flue gas to be exhausted from the ancillary chamber 202 to directing flue gas to be exhausted from the main chamber 201.

The flow control mechanism switch arrangement 308 may alternatively or additionally comprise a manually operable element (not shown) configured for allowing a user to selectively cause the flow control mechanism 303 to switch at least from directing flue gas to be exhausted from the main chamber 201 to directing flue gas to be exhausted from the ancillary chamber 202. The manually operable element may be mechanical and/or electrical and may be of any suitable type, for example, a button, a switch, a lever, a dial.

Thus, the closure device 306 of the flow control mechanism 303 can remain open during an initial, warm-up period of conventional burn, during which the temperature in the main chamber is rising, and upon the temperature in the main chamber reaching a temperature suitable for reverse-burn, the closure device 306 of the flow control mechanism 303 can be closed to prevent the flue gas from exiting the main chamber 201 through the aperture 307 and causing the flue gas to instead exit the main chamber 201 through the bed 304.

It is to be appreciated that the reverse-burn mode uses natural draft, the same as the conventional burn mode. Thus, advantageously, the solid fuel appliance design does not require or utilise fan, such as is used with induced draft and forced draft.

The catalytic converter 302 beneficially removes pollutants from the flue gas whether the solid fuel appliance 101 is operating in a normal burn or reverse burn setting, and thus during warm-up and burn-out phases as well as during the main burn phase.

The incorporation of the catalytic converter 302 into the solid fuel appliance 101 according to the present invention provides other benefits, such as those that will now be specifically mentioned.

When active, the temperature of the catalytic converter can be higher than the exiting flue gas, serving to increase and maintain flue temperature, in turn creating better natural draft and preventing condensation in the flue.

If reverse burn is struggling to activate, the catalytic converter pre-heating the flue can induce the reverse burn activation.

Combustion air is preheated during reverse burn, increasing burn efficiency and transferring heat back into firebox.

The combustion air requirement is fixed; there is minimal or no end user control over air flow.

The catalytic converter is sited to remove pollutants during warm-up and burn-out phases of combustion.

Whilst reverse burn dramatically reduces particulate matter and organic gaseous compounds (unburnt hydrocarbons), it does not eliminate CO (Carbon Monoxide) emissions. The catalytic converter (which works passively, and utilises heat from the solid fuel appliance) reduces this CO, for example to between 0.01% to 0.04%, but potentially down to approximately 0.001%. Additionally, during start-up when the flue gases are conventionally flowing up rather than being forced down, it also dramatically reduces CO, Organic Gaseous Compounds, and to a certain extent particulate matter making for cleaner emissions during start up and shut down.

In an example, and in the specific illustrated example, the catalytic converter 302 is disposed within a flue spigot 309.

With this positioning, the catalytic converter 302 is beneficially pre-heated at start-up. A passive catalytic converter requires heat from the fire to activate, and therefore in the present invention heat is provided to the catalytic converter 302 even during the earliest phase of combustion. Resistance in the flue caused by the presence of the catalytic converter is overcome in the present invention by providing plentiful free air.

In an example, and in the specific illustrated example, the catalytic converter 302 is removable. The removability of the catalytic converter facilitates maintenance.

In an example, the catalytic converter is removable through a hatch that is also a sweep hatch.

In an example, and in the specific illustrated example, a first portion 310 of the ancillary chamber 202 extends below the main chamber 201 and a second portion 311 of the ancillary chamber 202 extends behind the main chamber 201, substantially perpendicularly to the first portion 310.

In an example, and in the specific illustrated example, an air intake channel 312 is disposed behind the main chamber 201 and in front of the second portion 311 of the ancillary channel 202.

In an example, the air intake arrangement 301 is provided with a direct air supply connection arrangement, indicated generally at 313, for connecting the air intake arrangement 301 to an external direct air supply duct The solid fuel appliance can therefore be a room sealed unit when connected to a direct external air kit.

The solid fuel appliance may be a radiant stove or a convection stove.

The solid fuel appliance can be manufactured to be aesthetically appealing, suitable for use in a domestic environment, for example in a living room (which may also be termed a sitting room or a lounge). The solid fuel appliance can incorporate and/or present different shapes and/or finishes, and dimensions and colourways can be varied. Consumer preferences can therefore be accommodated.

Although illustrative embodiments and examples of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiment and examples shown and/or described and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope of the invention as defined by the appended claims.

Claims

Claims I. A solid fuel appliance, the solid fuel appliance operable in a conventional burn mode and in a reverse-burn mode, the solid fuel appliance comprising a catalytic converter through which flue gas from combustion of a solid fuel in either of the conventional burn mode and the reverse-burn mode is exhausted.
2. The solid fuel appliance of claim I, wherein the solid fuel appliance is a natural draft stove.
3. The solid fuel appliance of claim I or claim 2, for burning wood.
4. The solid fuel appliance of any preceding claim, comprising: a combustion chamber, comprising: a main chamber for receiving a solid fuel to be combusted, and an ancillary chamber, in communication with the main chamber, an air intake arrangement for permitting air to be admitted into the combustion chamber; a flue, for permitting flue gas to be exhausted from the combustion chamber, a catalytic converter, and a flow control mechanism, operable to direct flue gas to be exhausted from: the main chamber, along a first exhaust flow path passing through the catalytic converter, or the ancillary chamber, along a second exhaust flow path passing through the catalytic converter.
5. The solid fuel appliance of claim 4, wherein the flow control mechanism is operable to: during a first period of combustion, direct flue gas to be exhausted from the main chamber, and during a second period of combustion, direct flue gas to be exhausted from the ancillary chamber.IS
6. The solid fuel appliance of claim 5, wherein said first period of combustion is an initial period of conventional combustion and said second period of combustion is a subsequent period of reverse-burn combustion.
7. The solid fuel appliance of claim 5 or claim 6, comprising a flow control mechanism switch arrangement operable to cause the flow control mechanism to switch from directing flue gas to be exhausted from the main chamber and directing flue gas to be exhausted from the ancillary chamber.
8. The solid fuel appliance of claim 7, wherein the flow control mechanism switch arrangement comprises a temperature detection arrangement configured for detecting when a temperature in the combustion chamber has exceeded a threshold temperature, and wherein commencement of said subsequent period of combustion is on detection of a temperature in the combustion chamber exceeding the threshold temperature.
9. The solid fuel appliance of claim 7 or claim 8, wherein the flow control mechanism switch arrangement comprises a manually operable element configured for allowing a user to selectively cause the flow control mechanism to switch from directing flue gas to be exhausted from the main chamber to directing flue gas to be exhausted from the ancillary chamber.
10. The solid fuel appliance of any one of claims 5 to 9, wherein a bed provides the ancillary chamber in communication with the main chamber, the bed defining a pathway for allowing a passage of gas therethrough.
II. The solid fuel appliance of claim 10, wherein the pathway allows the passage of: air into the main chamber when the flow control mechanism is directing flue gas to be exhausted from the main chamber, and flue gas from the main chamber into the ancillary chamber when the flow control mechanism is directing flue gas to be exhausted from the ancillary chamber.
12. The solid fuel appliance of any one of claims 5 to I I, wherein a first portion of the ancillary chamber extends below the main chamber and a second portion of the ancillary chamber extends behind the main chamber, substantially perpendicularly to the first portion.
13. The solid fuel appliance of claim 12, wherein an air intake channel is disposed behind the main chamber and in front of the second portion of the ancillary channel.
14. The solid fuel appliance of any one of claims 5 to 13, comprising a door for providing access into the combustion chamber, wherein the door is common to the main chamber and the ancillary chamber.
15. The solid fuel appliance of any one of claims 5 to 14, wherein the catalytic converter is removable.
16. The solid fuel appliance of any one of claims 5 to 15, wherein the catalytic converter is disposed within a flue spigot
17. The solid fuel appliance of any one of claims 5 to 16, wherein the air intake arrangement is provided with a direct air supply connection arrangement for connecting the air intake arrangement to an external direct air supply duct.