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Patent Searching and Data


Title:
BURNING DEVICE
Document Type and Number:
WIPO Patent Application WO/2003/019077
Kind Code:
A1
Abstract:
The invention relates to a burning device particularly for burning so-called pellets, including a barrel-like component (4), in which the pellets or similar fuel are placed. The device also includes a second, bottomless and coverless barrel component (2) fitting inside the barrel-like component (4) and supported on the upper surface of the pellets (7), in such a way that both component (4) and component (2) have holes in their jacket surfaces. The components (2, 4) are cylindrical and fit telescopically inside each other. The lower component (4) preferably has a perforated grate component (5), in a position raised above the lower edge of the component (4).

Inventors:
HYTOENEN ONNI ILMARI (FI)
Application Number:
PCT/FI2002/000685
Publication Date:
March 06, 2003
Filing Date:
August 21, 2002
Export Citation:
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Assignee:
PIETI PAULI (FI)
HYTOENEN ONNI ILMARI (FI)
International Classes:
F23G7/10; F23L9/02; F24B1/02; F24B1/26; F24B3/00; (IPC1-7): F23B1/36; F23L9/02; F24B1/02
Domestic Patent References:
WO1999021465A11999-05-06
WO1996033109A11996-10-24
Foreign References:
SE87199C1
DE806582C1951-06-14
Attorney, Agent or Firm:
Laitinen, Pauli S. (Patentti-Laitinen OY P.O. Box 29 Espoo, FI)
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Claims:
Claims
1. A burning device, particularly for burning socalled pellets, including a barrellike component (4), in which the pellets or similar fuel are placed, characterized in that it also includes a second, bottomless and coverless barrel component (2) fitting inside the barrellike component (4) and supported on the upper surface of the pellets (7), in such a way that both component (4) and component (2) have holes in their jacket surfaces.
2. A burning device according to Claim 1, characterized in that the components (2,4) are cylindrical and fit telescopically inside each other.
3. A burning device according to Claim 1 or 2, characterized in that the lower component (4) has a perforated grate component (5) in a position raised above the lower edge of the component (4).
4. A burning device according to Claim 1, characterized in that the component (4) is perforated essentially over its entire jacket surface, but the component (2) has holes only in the vicinity of its lower edge.
5. A burning device according to Claim 1, characterized in that the holes in the jacket surfaces of the components (2,4) are of such a type and density that open holes for combustion air (3) to enter the device always remain near the upper surface of the pellet charge.
6. A burning device according to Claim 5, characterized in that the holes in the upper component (2) are essentially larger than the holes in the lower component (4).
7. A burning device according to any of the above Claims, characterized in that its crosssection is a circular cylinder.
8. A burning device according to any of the above Claims, characterized in that its components (2,4) are manufactured from sheet metal.
Description:
Burning Device The present invention relates to a burning device and particularly to a burning device, by means of which it is possible to burn particularly wood pellets.

At present, wood pellets are burned in relatively large amounts, as they have a high thermal value and are easy to use. A pellet is a particle form of wooden raw material, which has been compressed mechanically to a specific hardness and to specific dimensions. Pellets are burned in many types of furnace and boiler plant, often, however, in unsatisfactory conditions, in that even combustion and optimal combustion conditions are seldom achieved.

If the pellets are burned in equipment incorporating fans, feeder devices, and similar, the plant easily becomes very expensive and complex, and is completely unsuitable for small-scale operation, such as in a conventional furnace, or, for instance, without a furnace. In such applications, the drawbacks of combustion in non-optimal conditions are aggravated.

The present invention is intended to create a burning device, which is particularly suitable for burning wood pellets and which can be used together with conventional furnaces, or to achieve powerful combustion and at least nearly optimal conditions in all situations in which use of the burning device according to the invention can be envisaged.

These and other benefits and advantages of the invention are achieved in the manner stated as characteristic in the accompanying Claims.

The following describes one preferred embodiment of the invention in greater detail, with reference to the accompanying schematic diagram showing a vertical cross-section of the device, without the invention being in any way restricted to it.

The device according to the invention is formed simply of two cylinders, referred to in the following as the upper cylinder 2 and the lower cylinder 4, set inside each other and able to move telescopically in relation to each other. As the upper cylinder 2 has a slightly smaller diameter than the lower cylinder 4, it is the inner cylinder. Though the cylinders are mainly circular in cross-section, this is in no way essential, circular cylinders having, however, obvious advantages in this construction.

The lower cylinder 4 is of perforated sheet metal, or in any event of fire-resistant material. The upper cylinder 2 has holes only in the lower part of its jacket surface, which is otherwise not perforated. The holes in the lower part of the upper cylinder 2 are clearly larger than the holes in the lower cylinder. The upper cylinder too is of a fire-resistant material. The perforation is intended to permit air to flow into the inner space of the cylinders and to direct the airflow precisely to the combustion surface. By making the holes in the upper cylinder larger than those in the lower cylinder, the supply of air is ensured at all times.

Air is needed precisely to maintain combustion.

The lower cylinder 4 is preferably equipped with a grate 5, which is supported by suitable retainers, for example the stud-like protrusions 6 shown in the figure, in a position raised slightly above the bottom of the lower cylinder. There is a suitable number of the studs, for example, at least three. The grate 5 is also perforated, so that ash forming in combustion can flow through the holes into the space below the grate 5. The wood pellets are marked with the reference number 7.

The device is made ready for use and operated as follows. The lower cylinder 4 is filled suitably with wood pellets 7, for example, until it is nearly full. The grate 5 is preferably attached to form the bottom of the cylinder 4. The upper cylinder 2 is placed inside the lower cylinder 4. In the figure, the upper cylinder 2 does not extend very far inside the lower cylinder 4, because combustion is only just starting. The lower edge of the upper cylinder rests on top of the pellets. The lower edge can, if desired, include some type of flange, but good operation

usually does not require this.

The cylinders are perforated in such way that open holes, through which combustion air enters, always run through the overlapping parts of the cylinders, the airflow being shown with the arrow 3. The pellets are suitable ignited on the surface, for example, using a convenient lighter fluid, which creates even ignition over the whole area. Because a certain chimney-effect is created in the device, the combustion feeds a good airflow which in turn supports excellent combustion. As combustion progresses, and the upper edge of the charge of pellets drops, the upper cylinder, which rests on the edge, also automatically drops, so that the combustion front lowers automatically and evenly, the conditions of the actual combustion event remaining essentially unchanged.

Practical tests have shown the combustion to be even and complete.

The device according to the invention can be used, for example, inside a furnace, instead of the furnace being fired with split firewood or similar. The device can be used placed directly on a conventional grate, or by using a suitable grate equipped with a recess. The device according to the invention is also suitable for use as a camping-cooker type heat source, because as the device's dimensions are in no way restricted, it can be manufactured in either a very small size, or if desired, in a quite large size. Outdoors, it can be used as a 'lumberjack's candle'type of light source, for example, to decorate a party area.

It is obvious that, in addition, to variations in size, the manufacturing material and shape of the device can be varied within very broad limits. Cheap versions of it can be made using cheap raw materials, while the possible variations are greatly increased if very durable materials are used, or, for example, materials that create a beautiful external appearance.

Other variations, which remain within the scope defined by the basic inventive idea and the accompanying Claims, are also possible.