GB2379498A

GB2379498A - Oil fired pot burner

Info

Publication number: GB2379498A
Application number: GB0121872A
Authority: GB
Inventors: Guy David Lowman; Greg Richard Taylor
Original assignee: Gazco Ltd
Current assignee: Gazco Ltd
Priority date: 2001-09-11
Filing date: 2001-09-11
Publication date: 2003-03-12
Also published as: GB0121872D0

Abstract

An oil fired burner of the kind which includes a pot 10 defining an oil vaporising chamber 18 and having an inlet for oil20, an array of air inlets 25, and a bed 33 of imitation solid fuel which is supported above the chamber for combustion around the imitation solid fuel, in which the pot is of elongate shape with consistent combustion and low risk of work hardening or metal fatigue. The pot includes a pair of substantially arcuate outwardly curved end sections joined by a pair of substantially arcuate outwardly curved side sections. The side sections are longer than the end sections and have a shallower curvature. The pot is the preferably symmetrical, the preferred form of pot being elliptical

Description

OIL FIRED BURNER TECHNICAL FIELD OF THE INVENTION This invention relates to oil fired burners of the kind which are used in stoves and similar oil-burning appliances BACKGROUND WO 94 28358 discloses an oil fired burner which includes a pot forming an oil vaporisation chamber and which has a bed of imitation solid fuel supported on a baffle above the vaporisation chamber to provide a live flame effect. Invariably In burners of this kind the pot is circular (i. e cylindrical) as illustrated in the aforementioned specification, although it IS stated that the pot "could be of other shape such as rectangular". However, In practice there is a serious problem with non-circular shapes, which anses from the fact that, In use, both the baffle and the walls of the pot become extremely hot, to the extent that these parts usually glow red hot. As a result, any generally flat surfaces are prone to distortion and work hardening, which may be worsened by the fact that the spacing between the baffle and the walls of the pot may change resulting In variable combustion

performance Thus, a rectangular pot as suggested in the aforementioned specification has been found to permanently distort and/or suffer from work fatigue after only a short period of use, irrespective of the materials used and incorporation of various mechanical strengthening methods.

A burner of generally elongate shape would be very useful and would, for example, allow the construction of stoves which are wide and relatively shallow from front to back.

The present invention seeks to provide a new and inventive form of oil fired burner of the kind which includes a bed of imitation solid fuel, in which the burner IS of generally elongate shape whilst having a long and useful service life.

SUMMARY OF THE INVENTION The present invention proposes an oil fired burner which includes a pot having a side wall and a base defining an oil vaporising chamber and having an Inlet for oil, air Inlet means, and a bed of imitation solid fuel which is supported above the chamber for combustion around the imitation solid fuel, characterised in that the side wall of the pot includes a pair of substantially arcuate outwardly curved end sections joined by a pair of substantially arcuate outwardly curved side sections, the side sections being longer than the end sections and having a shallower curvature than the end sections

By making the pot generally oval and eliminating any significantly flat regions the working life of the burner may be comparable to that of a conventional round burner. On the other hand, the presence of relatively short flat regions in any of the wall sections may not significantly reduce the life of the burner so that any of the substantially arcuate wall sections could be multi-faceted, formed with a series of short flat facets arranged in a generally arcuate configuration Although the wall of the pot need not be perfectly symmetrical it is preferable if the end sections are mutually substantially Identical as are the side sections so that stresses are distributed symmetncally throughout the pot.

The preferred shape of the pot is substantially elliptical, although other similar oval shapes can be used BRIEF DESCRIPTION OF THE DRAWINGS The following description and the accompanying drawings referred to therein are included by way of non-limiting example in order to illustrate how the invention may be put into practice. In the drawings.

Figure 1 is a vertical section through an oil fired burner in accordance with the invention, Figure 2 is a horizontal cross section through the burner on

the line N-tt of Fig 1, and In which the position of the vertical section of Fig. 1 is Indicated by the line t-t, and Figure 3 is a similar horizontal section through an alternative shape of oil fired burner In accordance with the invention DETAILED DESCRIPTION OF THE DRAWINGS Referring to Fig. s 1 and 2, the burner 1 has a rectangular case 2 formed by a rectangular bottom wall 3, a pair of relatively long side walls 4 and 5 and a pair of relatively short end walls 6 and 7 The case contains a pot 10 having a continuous side wall 11 closed at the lower end by a bottom wall 12 When seen In plan view as in Fig. 2 the pot 10 is substantially elliptical such that the side wall 11 has a pair of short arcuate end sections, indicated 11 a and 11 b, joined by a pair of arcuate side sections, indicated 11 c and 11 d, having a shallow curvature relative to the two end sections The upper margin of the side wall 11 is joined to the top margins of walls 4-7 by a top wall 15. It will be noted that the wall 11 IS spaced from the walls 4-7 at all points, and the bottom wall 12 of the pot 10 IS also spaced from the bottom wall 3 such that a substantially enclosed air space 16 isformed between the pot 1 0 and the case 1 The pot forms a vaporisation chamber 18 to which oil 19 IS admitted at a controlled rate through an oil Inlet 20 passing through the walls 7 and 11, or any other two adjacent walls of the pot and case. At a slightly higher level (though not necessarily above the oil Inlet 20) an Ignition port 21 extends

through both of the walls 7 and 11. The pot also contains a removable flame ring 22 which is supported on legs or by other suitable means (not shown). One of the side walls 4 of the case 1 contains an air inlet 23 to admit pnmary combustion air into the space 16, and the side wall 11 of the pot 10 contains an array of ports 25 to admit primary combustion air from the space 16 Into the vaporisation chamber 18.

A horizontal baffle 28 of elliptical outline is removably supported above the vaporisation chamber 18. The baffle is surrounded by continuous downwardly extending elliptical wall 29 which is spaced within the wall 11 and is provided with lugs 30 which rest on the top wall 15. The baffle 28 is formed with a plurality of burner apertures 31 each having a punched lug 32 extending upwardly from one side thereof. A bed 33 formed of ceramic elements is supported on the baffle 28 to simulate pieces of solid fuel such as coals, logs, briquettes or the like. (A single ceramic moulding could also be used. ) The lugs 32 ensure that the ceramic elements do not obstruct the burner apertures 31.

When oil on the wick mat 19 is ignited through the lighting port 21 the flame IS initially confined to the lower part of the chamber 18 below the flame ring 22, but as the pot heats up the oil starts to vaporise within the chamber and the level of burning vapour within the chamber gradually rises. When the vapour level reaches the ports 25 the vapour mixes with primary combustion air entering the chamber through the ports 25 and the flames enter the space between the inner wall 11 and the depending wall 29, heating the baffle 28 and bed 33. Eventually the vapour emerging from the burner apertures 31 ignites between the ceramic elements of the bed 33 to provide

a live flame effect with flames emerging from the Imitation fuel bed As the baffle 28 and the bed 33 heat to their normal operating temperature the side wall 11 of the pot 10 and the depending wall 29 become extremely hot, but they tend to expand outwards in all directions maintaining a substantially uniform spacing between the walls 11 and 29 which minimises the occurrence of localise hot regions When the burner cools the walls 11 and 29 contract substantially uniformly, thereby minimising work hardening and metal fat ! que Stnce the outer case 1 IS subjected to a considerably lower temperature than the pot 10 and baffle 28 no metal fatigue problems are normally encountered Although a substantially elliptical pot achieves good results other similar oval shapes are capable of achieving acceptable results For example, the ends 11 a and 11 b may be part-circular with the sides 11 c and 11 d also being part-circular but with a larger radius of curvature as shown In Fig. 3 Moreover, although a rectangular outer case 1 is easy to manufacture and convenient to accommodate In many appliances it could also be elliptical or of any other convenient elongate shape It will be appreciated that the features disclosed herein may be present In any feasible combination Whilst the above description lays emphasis on those areas which, in combination, are believed to be new, protection is claimed for any Inventive combination of the features disclosed herein

Claims

CLAIMS 1 An oil fired burner which Includes a pot having a side wall and a base defining an oil vaporising chamber and having an inlet for oil, air inlet means, and a bed of imitation solid fuel which is supported above the chamber for combustion around the Imitation solid fuel, charactensed in that the side wall of the pot includes a pair of substantially arcuate outwardly curved end sections joined by a pair of substantially arcuate outwardly curved side sections, the side sections being longer than the end sections and having a shallower curvature than the end sections
2 An oil fired burner according to Claim 1, In which the end sections are mutually substantially identical
3 An 011 fired burner according to Claim 1 or 2, in which the side sections are mutually substantially identical
4 An oil fired burner according to Claim 1,2 or 3, in which the pot IS substantially elliptical.
5. An oil fired burner according to any preceding claim, In which any of the substantially arcuate wall sections are multi-faceted, formed with a series of short flat facets arranged In a generally arcuate configuration

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6 An oil fired burner substantially as described with reference to the drawings