WO1997011627A1

WO1997011627A1 - Heating device

Info

Publication number: WO1997011627A1
Application number: PCT/GB1996/002344
Authority: WO
Inventors: Michael John Keith Bayliss
Original assignee: Potter & Soar Limited
Priority date: 1995-09-27
Filing date: 1996-09-24
Publication date: 1997-04-03
Also published as: AU6997096A

Abstract

A frame member (1), of triangular channel or tubular shape covers a firelighter block (4) in a body of charcoal in a barbecue and is dimensioned to provide sufficient clearance (5) for a draft of air to flow over the firelighter.

Description

HEATING DEVICE

The invention relates to heating as in barbecues, fireplaces, camp fires and the like More particularly the invention is concerned with the heating of foodstuffs as in cooking on barbecues or like fires where solid fuel is used. The invention will be described with specific reference to barbecues.

It is well known that a firelighter is first lit to ignite charcoal or like solid fuel The firelighter may be a solid impregnated with an inflammable compound, e.g. hydrocarbon Usually such firelighters are placed in a barbecue tray and lit, either before or after the lumps of charcoal have been placed in the tray It is notonous that it takes a long time to get the charcoal to ignite The patent literature is replete with ideas to address this problem see, e g

US-A-2488014 US-A-4603679 SE-A-470279 WO-A-87/00017 ZA-A-82/01713 US-A-4782812 ZA-A-83/2210 GB-A-2249946

US-A-5269286

These disclosures offer a range of proposals, which may work to some extent All however are directed to how to achieve ignition of the firelighter For example US-A- 5269286 relates to a combustion chamber for use with a solid fuel in a barbecue, and provides a lower box shape to receive a firelighter block above which is an inclined gnll roof shaped to exclude wind and dust The disclosure says that the ignition rate of the firelighter is better and the flames are passed through the holes in a concentrated way to ignite the charcoal in less time

This invention is based on the realisation that by locating a firelighter within a defined frame member therefor not only will the firelighter bum better but the charcoal will ignite more quickly and can bum at a higher temperature and cook the food better

According to the invention in one aspect there is provided a barbecue compnsing a tray having a base and sidewalls, the tray being provided with lumps of charcoal or like solid fuel and with a consumable firelighter to ignite the solid fuel, the firelighter being present in a frame member having perforations which allow the flame to pass through but exclude the solid fuel characterised in that the frame member is dimensioned so that the firelighter is surrounded by air to allow a current of air to be drawn through the frame member by the burning process into the charcoal As a result the firelighter burns more efficiently and the fuel bums at an enhanced temperature

Preferably there is a clearance, preferably of at least 3 mm, between the peπphery of the firelighter and the intenor of the frame member Preferably the frame member is in the form of a tube or channel It is preferred for the channel or tube to be perforated in whole or in part but this is not essential In one preferred embodiment the frame member is of generally tubular shape In another option the frame member is of channel shape compnsing a roof and side walls, and is inverted in use The frame member to be secured to a barbecue tray during or subsequent to the manufacture of the barbecue tray, or it may simply be placed thereon.

Preferably the frame member is a press formed, pre-fabricated or otherwise manufactured device in the form of a triangular tunnel, inverted 'U' shape or other suitable configuration, with or without open ends or openings, constructed from metal or other non-combustible, i.e. refractory material in the form of mesh, expanded metal, welded wire, perforated sheet or otherwise, with slots or apertures of a size which prevents small pieces of the charcoal and much of the charcoal dust from passing through (which could otherwise snuff out the flame of the ignited firelighter), and yet allows heat and flames to pass through easily, and overall is of sufficient strength to support large quantities of charcoal, randomly tipped onto the extemal surfaces of the frame member. The frame member could be in the form of a single helical coil with the winding spacing selected to prevent small pieces of charcoal and much of the charcoal dust from passing through. For example the winding spacing could be 5 mm

The frame member is preferably formed of a refractory non-toxic mateπal. Typically the member is made of metal such as steel, e.g. mild steel or preferably stainless steel.

In use, the frame member is simply placed onto the base of a barbecue (which may be in the form of a flat surface or a series of rods) with one or more firelighter bricks or blocks placed in the chamber so formed between the frame member and the barbecue floor The firelighter may be ignited before or preferably after the frame member is in place Being surrounded on all sides (except the base) by an unlimited supply of air the firelighter is able to bum freely with the flames passing through the slots and apertures in the frame member Charcoal can then be added in whatever quantities may be required, by simply tipping it out of a bag into the barbecue and onto the frame member Flames from the buming firelighter pass through the slots or apertures in the frame member alongside the current of air which is drawn in by the burning process, thereby causing the charcoal to ignite

An open end or other opening is preferably present for further firelighter blocks to be inserted into the chamber to continue the igniting process or to reactivate the burning process once the oπginal charcoal has been consumed Preferably both ends of the tube or channel are open in order to provide or enhance flow of air to the firelighter

Preferably the frame member measures at least 11 cm long, preferably up to 15 cm, the preferred cross section area of the member is at least 20 cm² for a conventional 2 5 x 2 5 x 5 cm long firelighter and there is ideally at least 3 mm clearance between the firelighter and the frame

In another preferred embodiment there is provided a frame member having one, two or more 'wings' or lateral extensions of a sufficient strength in the form of mesh, expanded metal, welded wire or rod, perforated sheet or otherwise with slots and/or apertures of a size which prevents small pieces, and larger pieces of charcoal from passing through, and of a sufficient strength to support a quantity of charcoal randomly tipped directly upon and in direct contact with the burning firelighter Charcoal is prevented by the 'wings' of the device from coming into contact with the sides of the burning firelighter thereby preventing the charcoal from snuffing out the flames on the sides of the burning firelighter which in turn maintains the buming process on the sides of the burning firelighter thereby ensuπng ignition of the charcoal

Because the presence of the frame member the ignition is improved and the charcoal reaches a high temperature There is an immediate sealing of the surface of meat, fish or similar food as it is placed on the cooking gnll Steak for example can be cooked on the outside and left rare in the inside as preferred by many people Furthermore, droplets of fat from meat immediately vapouπse upon coming into contact with the very hot charcoal and do not cause the charcoal to burst into flame as is the case with conventional barbecues

Of course where the invention is applied to a fire device other than a barbecue, e g fireplace or camp fire, the frame member is located appropriately

The invention extends to the frame member per se, dimensioned and adapted for use in a barbecue, fireplace, camp fire or like device It is within the scope of the invention to provide a package compnsing a sealed container containing a number of firelighter blocks and one frame member

In order that the invention may be well understood it will now be described by way of example with reference to the accompanying drawings in which

Figure 1 shows in perspective and elevation of one frame member,

Figure 2 shows the frame member with ignited firelighter in position Figure 3 shows the frame member with the firelighter and charcoal in position,

Figure 4 shows in perspective another embodiment of frame member, and

Figure 5 illustrates the member of Figure 4 with ignited firelighter in position

Refemng to Figure 1 , the frame member comprises a formed or pre-fabπcated metal structure 1 of generally tnangular sectional shape having side walls 2 constructed with slots or apertures 3 The member may be supplied in a flat or kit form for erection or assembly by the user, for example by being hinged at the apex As shown in Figure 2 when the member is placed on the tray base of a barbecue B, a chamber is formed which provides sufficient clear space or clearance 5 about an ignited firelighter 4 to enable the flames 6 to burn freely ana unrestπcted (see Figure 2) This in tum provides an effective flame able to ignite the charcoal which bums at an enhanced temperature

As shown in Figure 3 the frame member is of sufficient strength to support a quantity of charcoal 7 and the slots or apertures 3 are small enough to prevent small pieces of charcoal and much of the dust from passing through, yet are of sufficient size to allow the flames and heat 6 to pass into the charcoal 7

One or both ends of the member may be open 8, or other openings may be provided, to enable further firelighter blocks or bπcks to be inserted In use a continuous draught of air is created through the frame member of the embodiments shown and in to the charcoal, which in tum energises the charcoal buming process. This increases the temperature of the 'fire' substantially which apart from improving the cooking process, causes droplets of fat which fall from the food to immediately vapourise.

The frame member shown in Figure 4, comprises a pre-fabricated metal structure 10 with open sides 12 and with the uppermost lateral extensions or 'wings' 13 constructed flat, curved, angled or such like with slots and/or apertures 14 therein and with a central elongate channel 15. The configuration shown is in the form of, but is not limited to, a central channel 15 with flat rectangular wings 13. It may for example be circular in shape with a rectangular recess into which a firelighter can be placed. It may or may not have 'legs' 16 to prevent the device from tipping when charcoal is added. As shown in Figure 5, the member permits all exposed surfaces of the firelighter 17 received in the channel 15 to bum freely 18.

The invention is not limited to the embodiments shown. For example, the frame member need not be perforated.

Claims

1. A barbecue or like device comprising a tray having a base and sidewalls, the tray being provided with lumps of charcoal or like solid fuel and with a consumable firelighter to ignite the solid fuel, the firelighter being present in a frame member having perforations which allow the flame to pass through but exclude the solid fuel characterised in that the frame member is dimensioned so that the firelighter is surrounded on all sides (except the base) by air to allow a current of air to be drawn through the frame member by the buming process into the charcoal.

2. A device according to Claim 1 , wherein the frame member is of generally tubular shape.

3. A device according to Claim 1 or 2, wherein the frame member is of general channel shape comprising a roof and side walls and is inverted in use.

4. A device according to Claim 1 or 2, wherein the frame member is of triangular cross-sectional shape.

5. A device according to any preceding Claim, wherein the frame member is made of a mesh, expanded metal, welded wire, perforate sheet or a helical coil.

6. A device according to Claim 5, wherein the frame member is made of stainless steel.

7. A device according to any preceding Claim, wherein the frame member measures about 11 cm to about 15 cm long, has a cross sectional area of at least 20 cm², and has a clearance of at least 3 mm around a 2.5 cm x 2.5 cm cross-section firelighter.

8. A device according to any preceding Claim, secured to the base of the barbecue tray.

9. A frame member for use in a barbecue or the like comprising a mesh made of stainless steel, having the general channel shape, and measuring about 11 to 15 cm long, and having a cross-sectional area of about 20 cm².