GB2512417A - Stove and burner - Google Patents

Abstract

A stove comprises an outer container 12 including a first wall section 13, a first base 14, and a first opening 15 and an inner container 16 including a second wall section 17, a second base 18 which includes one or more holes 21 and a second opening 19. The inside of the inner container forms a burner or combustion chamber 26, and the inner container is held coaxially within the outer container such that there is a space between the inner container and the outer container. The inner container may include a plate 22 located above the second base with a plurality of apertured tubes 30-32 coaxially mounted on the plate. The stove may be operated by pre-heating with a heating element or by igniting starter material in the combustion tube and dripping liquid fuel from a tap or valve at a predetermined rate into the combustion chamber. The stove may include a lid 40 with a flue 46, and may be dismantled and the components stored in the outer container for portability.

Description

Stove and Burner

Technical Field

The present invention relates to a clean-burning stove which is able to burn solid or liquid fuel, and which is able to be folded away for portability. The invention also relates to a clean burning burner.

Background Art

Any discussion of the prior art throughout the specification is not all admission that such prior art is widely known or forms part of the common general knowledge in the field.

T]1e use of small, portable, fuel-burning stoves is a cheap way of providing heat and/or providing a means of heating water or cooking food. This is particularly important in third world countries, where electricity for cooking may not he readily available. Such portable stoves are also convenient for use while camping, where a contained stove is safer than open fires. Tt is preferable to avoid excess smoke from the combustion of fuel in sucE stoves, and as such there has been a trench to design stoves in such a way that tile emissions are smokeless or near smokeless. Efficient burning of the fuel is also extremely desirable, as it reduces the amount of fuel required to produce a set amount of energy. It is also preferable that such stoves are inexpensive and easy to construct.

Oils such as vegetable oils or petroleum oils, even including dirty waste sump oil, present a potential fuel source, particularly the waste oils, which would otherwise need to be disposed of. Many portable fuel-burning stoves have been designed to reduce smoky emissions, however most are not adapted to burn liquid fuels. For exaniple, the portable stove described in US 6,615,821 atilises a downward draft between multiple walls to pre-heat the air prior to its entry into the side of the combustion chamber, but is not adapted for the burning of liqtild fuel.

Similarly, US 4,91 5,091 discloses a cooker/space heater made from arcuate metal shells which is designed such that tile air is pre-heated before entering the area where combustion occurs, but is again not adapted for the burning of liquid fuels.

There is a need for an efficient, clean burning portable stove which can utilise the potential energy source of oils, particularly waste oils. An object of tile invention is to provide a portable, inexpensive, clean-burning, multi-fuel stove, which can be used as a heater, a grill, or stove. A further object of tile invention is to provide a portable stove which can be easily dismantled and held within a single container ft r pt)rtahility.

Summary of the Invention

The present invention provides a stove which includes: an outer container which includes: a first snail section; a first base; and a first opening; an inner container which includes: a second wall section; a second base which includes one or more holes; and a second opening; wherein the inside of the in net container fonns a combustion chamber in use, and w]'erei n the in [let container is held coaxially within the outer container such that there is an inter-container space between tile inner container and the outer container.

Preferably, a plate located within the inner container and which is raised above the second base; and at least one apertured tube is located oil the plate.

A heater element may he provided. Such a heater element is preferably configured to pre-heat the plate and/or the at least one aperture tube located on the plate. The heater element may he configured to pre-heat the combustion chamber and is preferably configured to pie-heat the outer aild inner coiltailleis.

Preferably, the first wall section and the second wall section are the same configuration. Preferably the first wall section and the second wall section are cylindrical.

Preferably the hole is located in the cetitre of die second base.

Preferably the apertured tube(s) are circular in cross-section, and are preferably arranged coaxially with the inner container and outer container. Preferably said apertured tubes are arranged coaxially, and are of progressively smaller diameters.

Preferably the stove further includes a lid which covers the opening of the inner container.

Preferably the lid inclndes a fine throngh which exhanst gases escape in use. Preferably the lid includes a lid hole, which can preferably he partially or fully closed by any known means.

Preferably the stove includes a liquid fuel feeder, which may be an oll fuel feeder, configured to drip liquid fuel into the combustion chamber at a predetermined rate. Preferably said llquid fuel is fed by avitv, and is preferably controlled by a tap or valve.

Preferably said stove further includes a grill winch can be placed over the second opening such that food may he heated or cooked over the stove Alternatively, the stove may be used for cooking by placing a cooking receptacle on the lid, thereby providi rig for cooking without a naked flame.

Preferably the stove can he dismantled and all components of the stove held within the outer container.

Preferably. in use, air is drawn through the first opening into die inter-container space, upwards through the hole into the combustion chamber, around the plate, and either upwards or through the apertures of the apertured cyhnder into the space above the centre of the plate, where combustion with fuel occurs. Advantageously, when the stove is up to operaung teniperature, the incoming air is superheated.

ibis gasifles the fuel, to obtain au efficient buru.

The prcsent invention further provides a method of using the stovc describcd above for burning liquid fuels, wherein a starter material is placed in the combustion chamber, ignited, and once a flame has begun to die down, the oil feeder is turned on and liquid fuel is trickled into the combustion chamber at a predetermined rate.

Preferably. the method of using a stove comprises the steps of: pre-heating at least the plate; and introducing liquid fuel into the combustion chiamher at a predeterniined rate.

Preferably, die combustion chamber is pre-heateel and more preferably die inner and outer containers are pre-heated. \Vith the inner and outer containers pre-heated the whole stove in fact is pre-heated.

Adwmtageously, wherein the combustion chamber is pre-heated, arid preferably the step of pre-heating comprises placing a starter material in the combustion chamber and igniting the starter materi:sl, arid wherein the step of pre-heating is complete when flames emanating from die ignited starter material have begun to die down, and wlierci i the liquid fuel feeder is turned on and liquid fuel is trickled into the combustion chamber at a predetermined rate after completion of the pre-heating step.

According to another aspect of the invention there is provided a burner comprising, a container including a wall section, a base which includes one or more holes and an opening, the burner further comprising a plate located within the container and which is raised above the base, and at least one apcrturcd tube located on the plate; and wherein the inside of the confiner forms a combustion chamber in use.

Advantageously, the wall section is cylindrical.

Preferably, the at least one apcrtured tube is circular in cross-section.

Preferably, the at least one aperture tube is arranged coaxially with the container.

The burner may comprise a plurality of aperture tubes, the apertured tubes arranged coaldally, and having progressively smaller diameters.

The burner advantageously includes a liquid fuel feeder, configured to drip liquid fuel into the S combustion chamber at a predetermined rate. Preferably, the said liqud fuel is fed by gravity. More preferably, the flow of liquid fuel is conolled by a flow control means. The flow control means may be a tap or valve Advantageously, thu contai ncr is an illeer container and the burner further comprises all outer container, wherein the outer container includes a first wall section, a first base, and a first opening, and wherein die wall section of the inner container is a second wall section, and the base of the inner container is a second base and wherein the inner container is held coaxially within tile outer container such that there is an inter-container space between the inner container and the outer container.

l'referably in use, air is drawn through the first opening into die inter-container space, upwards dirough the hole into the combnstion chamber, around the plate, and either upwards or through the apertures of the apertured cylinder into the space above the centre of the plate, where combustion with fuel occurs.

Causing the incoming air to follow the path described above results in the air becoming super-heated.

Fuel flowing into tile super-heated air is vapourized, burning like a gas rather than a liquid and hence gves a very clean burn.

By bringing tile burner or stove up to operating temperature before feeding ml tile liquid fuel stock all efficient burn from start up is provided for.

Brief Description of Drawings

By \vay of example only, a preferred embodiment of the present invention is described in detail below with reference to the accompanying drawings, in winch: Figure 1 shows a vertietd cross-section of the stove, and includes arrows indicating air flow on one side of the figure. The air flo\v has been indicated oii one side of the drawing only, but it is appreciated that tile air flows in this manner for tile entire stove; [Tigrire 2 shows a perspective view of the stove with the lid hole open.

Detailed Description of the Preferred Embodiments

A stove (10), shown in IFiglire 1, includes an outer container (12), which includes a first wall section (13) (which is preferably cylindrical), a first base (14) at the iower end of the first wall section (13), and a first opernug (15) at the upper end of the first wall section (13). The stove (10) also includes an inner container (16), which includes a second wall section (17) (which is preferably cylindrical), a second base (18) at the lower end of the second wall section (17), and a second opening (19) at the upper end of the second wall section (17). The second base (18) includes at least one h)ie (21), preferably at the centre of the second base (18), to allow for air flow.

The inner container (16) is held coaxially within the outer container (12) by container supporting means (not shown), such that there is a space between the first wall section (13) and the second wall section (17), and the first base (14) and the second base (16); this space is heteinaftet called the inter-container space (20). The inter-container space (20) is open to outside air by the first opening (15).

The inside of the inner container (16) forms a combustion chamber (26). Within the combustion chamber (26) and above the hole or holes (21) is a plate (22). The plate (22) is held above the second base (18) by plate supporting means (not shown) such that there is a space between the second base (18) and the plate (22), and a space between the edge of the plate and the second wall section (17). This arrangement allows air to flow from the inter-container space through tile hole (21) in the inner container base (18), up and around die plate (22), into the combustion chamber (26).

A plurallty of apertured tubes (30, 30', 31, 31', 32, 32'), which are preferably circular in cross-section, and are of progressively smaller diameters, is arranged coaxially on the plate (22). ihe apertured tubes are also coaxial with the first wall section (13) arid the second wall section (17). The apertuied tubes (30, 30', 31, 31', 32, 32') are shown in Figure 1 in vertical cross section. The items numbered 30 and 30' refer to a first apertured tube, 31 and 31' refer to a second apertured tube, and 32 and 32' refer to a third apcrturetl tube. It is appreciated that there may he any number of apertured tubcs, anti that although die preferred horizontal cross-section is circular, they may be tubes of any cross-section. A plurality of apertures is formed in the wall of each apertured tube (30, 30', 31, 31', 32, 32'). The apertures (33) of any one aperture tube need not align with the apertures (33) of any other apertured tube.

Thin stove further includes a lid (40) which is placed over the opening of the inner container (16), such that tile combustion chamber (26) is enclosed. The lid (40) includes a lid wall section (41) and a horizontal top section (42) at the top of the lid wall section. The horizontal cross-section of the lid wall section (41) is die same dimension and shape as the horizontal cross-section of die second wall section (17) such that the lid wall section (41) and the second wall section (17) allgn when the lid (40) is placed on the inner container (16). The inner container further includes an inner container flange (27) adjacent the second wall section (17) and peripherally around the second opetling (1 9). The lid (40) ]iasacon-esponding lid flange (43) around its open end, such that the two flanges align when the lid (40) is placed on the inner container (16). The inner container flange and the lid flange may he rcleasahly secured togethcr by any suitable means such that the lid does not move during operation of the stove.

The lid (40) also includes a lid hole (44) which, shown in Figure 2, may he closed fully or partially by ally known means (e.g. a door. In use fuel may he inserted into the combustion chainher (26) through the lid hole (44). The lid (40) further includes a flue (46) extending from the top section (42) through which exhaust gases escape in use. The lid may further include handles (not shown) for safe handling. The lid is removably secured to the inner container such that in use the lid does not move.

An oil feeder (50) is positioned through the lid (40). Alternatively said oil feeder (50) may be positioned through the inner container (1 6) and/or the outer container (12). The oil fecder is arranged such that oil falls into the combustion chamber (26) at approximately the centre of the plate (22) at a predetermined rate. The oil may he fed hy gravity and controlled by a tap or by other suitable means of known type. The best shape of the part of the oil feeder (50) which extends into the combustion chamber (26) is a straight tube, as this alloxvs the mhe to be cleared easily should it clog.

The stove is preferably made from a suitable nretal. Any handles may be made of a suitable insulating material such that during use they are cool enough to he touched.

Furthermore, for portability, the stove can be dismantled and all components of the stove held within the outer contai tier.

it is appreciated that the outer container, the inner container, and the apertured tuhes may he of any cross-section, however, circular cross-secth)n is the simplest and most econonucal to construct.

in use, the stove (10) is placed on the ground or other stable surface, resting on the first base (14).

Air enters the first opening (15), flows downwards into the inter-container space (20), and is heated by the hot second wall section (17), which in turn is heated by the combustion process within the combustion chambcr (26). The air enters the combustion chamber (26) through the hole (21) in the second base (18), and flows up\vards around the plate (22). The air then flows upwards or through the apertures (33) of the apertured tuhes (30, 30', 31, 31', 32, 32') into the space above the centre of the plate, where combustion occurs. This air flow is mdicateel by arrows in Figure 1.

For the process to be efficient, the air must be hcated as it descends through the inter-container spacc (20). Iherefore, it is advantageous that the components of the stove defming the inter-containcr space are pre-heated. This may be achieved in a number of ways. A pre-heater may be provided to beat the intel-container Space tnd/or the plate and/or the at least one apertured tube located on the plate, or combustible material may he placed iii t]1e StOVe at a suitahie location and he ignited. The stove may run for a period of time, heating the second wall section (17) before it is maximally efficient. The supply of liquid fuel may begin at the same time as the pie-heating phase, at the end of the pie-heating phase, or at a point during the pie-heating phase.

The stove (10) is capable of burning either solid fuels or liquid fuels. Solid fuels which are suitable for burning within the stove in the first configuration described below include paper brickettes and wood, however it is appreciated that this list is not exhaustive, and there are many other suitahle combustible solid fuels. Liquid fuels which are suitable for hurning within the stove in the second configuration described below include vegetable or petroleum oils, even including dirty waste sump oil.

When the stove (1 0) is desiret] to burn solid fuel, the plate (22) and the apertureti tubes (33) are removed arid the fuel is placed on the second base (18) and burned with or without the lid (40) on the stove. In nse in this first configuration it is necessary to periodically clear the hole (21) of accumulated ashes. A grill may he placed over the second opening (19)so that the stove can he used for cooking food, heating water, or any other desired uses.

\Xhen it is desired that liquid fuel is to he burned, die stove is arranged in a second configuration, wherein the plate (22) and apertured tubes (30, 30', 31, 31', 32, 32') are positioned within the inner container (16), and the oil feeder (30) positioned as described above. Although the initial ignition of stove could be executed in many ways, the hest method foutid to date is to place a quantity of diesel or kerosene in the combustion chamber (26), introduce a flaming section of paper towel or other suitablc material to the diesel or kerosene, and once a flame has begin to die down, indicating the stove has been preheated, turn the oil feeder on. This method of ignition preheats the stove.

Reference numerals (IC) Stove (45) (II) (46) Flue (12) Outer container (47) (13) First \vall section (48) (14) First base (49) (15) First opening (50) Oil feeder (16) Inner container (17) Second wall section (1$) Second base (19) Second opening (21)) Inter-con tai ncr space (21) hole (22) Plate (23) (24) (25) (26) Combustion chamber (27) In net con tai ncr flange (r\ (to) (29) (30) First apertured tube (31) Second apertured tube (32) Third apertured tube (33) Apertures (34) (35) (36) (37) (38) (39) (40) Lid (41) Lid wall section (42)Hori7ontal top section (43) Lid flange (44) Lidhole