TITLE OF INVENTION: HEATING MEANS

INTRODUCTION TO THE INVENTION:

This invention relates to heating means. More particularly, this invention relates to heating means including solid fuel elements and a method of making such heating means.

BACKGROUND TO THE INVENTION:

Solid fuel elements are known in the state of the art for example in the form of briquettes made from milled coal or charcoal and a binder. Such briquettes are generally used for heating and/or cooking food and more particularly for barbeques or outdoor cooking.

However, such briquettes suffer from various disadvantages. Inter alias these are dirty to handle or touch, are friable and prone to breakage, and require a so-

called (paraffin or other type of) fire-lighter to ignite. In addition, during ignition these briquettes are both thermally or energy inefficient and release a large amount of smoke and other compounds resulting in undesirable air pollution.

Although such briquettes may be made from any carbonaceous material, the most obvious material to use is coal fines which are regarded as a waste material at coal mines and which generally presents an environmental problem to these mines and surrounding areas. Hence it would be advantageous to use coal fines on a large scale as the essential raw material for making such fuel elements and if one could overcome, or at least reduce, the undesirable emissions problems associated with coal burning.

It would also be advantageous to use coal fines as the raw material for other heating applications such as domestic and commercial/industrial heating whilst overcoming, or at least reducing, the aforementioned emissions problems.

OBJECTS OF THE INVENTION

It is an object of the present invention to provide a heating means including solid fuel elements and a method of making such heating means that overcome, at least partly, the disadvantages of heating means forming part of the state of the art.

It is also an object of the present invention to provide a heating means and a method of making such heating means that are both new and involve an inventive step.

SUMMARY OF THE INVENTION

According to one form of the present invention, there is provided a solid fuel element including a carbonaceous material, a binder, limestone, an oxidizing compound, and a suitable zeolite.

The carbonaceous material may in a preferred form of the invention be run-of- mine coal fines, or milled coal, or maybe washed to remove non-carbonaceous material. In another form of the invention, charcoal, sawdust, wood shavings or woodchips, or any other suitable combustible waste material may be used, or even a blend of the aforementioned materials.

The binder may be a suitable starch material such as an industrial starch.

The limestone may be a typical, locally obtained, run of mine/quarry limestone containing a reasonable balance of calcium carbonate and magnesium carbonate.

The oxidizing compound may be potassium nitrate, sodium nitrate, and/or any suitable oxidizing compound.

The zeolite may in a preferred form of the invention be clinoptilolite.

In one form of the invention the solid fuel element may include the following ingredients in the respective quantities set out hereunder (based on the dry mass of the fuel used ie coal, anthracite or charcoal or any carbonaceous material blend):

Coal fines or a carbonaceous material (referred to as the fuel) Potassium nitrate - about 15% to 55% of the fuel Limestone - about 10% to 15% of the fuel Clinoptilolite - about 10% to 15% of the fuel Starch - about 1% to 10% of the total dry mass.

In a preferred form of the invention, the above ingredients may be provided in a finely ground form prior to, during or after mixing. Some or all of the ingredient particles may be milled to about 500 microns or smaller, or to even about 200 micron or smaller, depending on the particular application of the element or mixture.

An additional amount of about 2% hexamine or about 2 % magnesium in powder form, alternatively an additional amount of charcoal and potassium nitrate may be added to the above mixture to assist in initial ignition of the fuel element.

According to another aspect of the present invention, there is provided a method of making solid fuel elements, including the steps of:

drying run-of-mine coal fines or a carbonaceous material; milling such coal fines to about 500 microns or smaller; adding starch, limestone, oxidizing agent, and zeolite, each similarly milled to about 500 microns or smaller, to the coal fines; mixing the above components to provide a dry mixture; adding about 8% water by mass to the dry mixture and mixing to provide a wet mixture; placing the wet mixture in suitable moulds; compressing the wet mixture in the moulds at a pressure of about 20 to 300 metric tons per cubic cm to produce disc-like pucks; and drying the pucks at a temperature of at least 100 degrees Centigrade for about

60 minutes.

Alternative method of producing the pucks is to put the above ingredients into a twin screw compounder, mix the ingredients, add about 8% water and extrude the material through a die to form the puck or other desired shape.

The pucks may be produced in a round disc-like shape. In a preferred form, the disc will have a plurality of holes extending through the body of the disc from top to bottom.

In one form of the invention, the pucks may be used as produced above, by simply lighting with a match or other ignition means.

In another form of the invention the pucks may be soaked for a short while in a suitable hydrocarbon liquid, such as paraffin, or a suitable bio fuel to assist in easy ignition of the pucks and to provide a flare to burn up the volatiles that are driven off during the ignition process.

In yet another form of the invention, a suitable liquid hydrocarbon, such as paraffin or a suitable bio fuel, may be blended into the dry or wet mixture referred to above, to assist in easy ignition of the pucks.

According to yet another aspect of the present invention there is provided a method of heating and/or cooking, including the step of using solid fuel elements such as the pucks as described herein.

According to a stili further aspect of the present invention, there is provided a heating means being a mixture including coal fines or a carbonaceous material, limestone, an oxidizing agent and a suitable zeolite.

The above mixture, which excludes the binder, may otherwise include the ingredients substantially in the respective quantities and otherwise as set out above.

This mixture may include or exclude the oxidizing ?.gent, depending on the type of furnace the mixture will be used in and the temperature at which it is operated.

The aforementioned mixture may be provided in a suitably fine/pulverized form for pressurized injection through a particle burner to fire industrial furnaces or boilers such as used in industry or in power stations for example. The particle size of the mixture may for example be 500 micron or smaller, or even 200 micron or smaller, depending on various factors such as the quality of the coal fines and/or the type of furnace or boiler.

In another form of the invention, the mixture may be provided in a granulated or pellet form.

The invention therefore extends to both solid fuel elements and a pulverized fuel mixture whenever made by a method as herein described.

DETAILED DESCRIPTION OF THE INVENTION:

The invention will now be described in greater detail, by way of non-limiting illustration, with reference to the following examples:

Example 1

In a suitable pilot plant or industrial scale batch/blending plant, the following materials are dried, if containing moisture, and milled to about 500 microns or smaller (as may be required):

run-of-mine coal fines industrial grade starch run-of-mine/quarry or agricultural grade limestone industrial grade potassium nitrate and/or sodium nitrate industrial grade zeolite, more particularly in the form of clinoptilolite.

These ingredients are then blended in an industrial drum blender in the following proportions (by mass relative to the mass of carbonaceous material ie coal fines):

Carbonaceous material (referred to as the fuel) Potassium nitrate - about 45% of the fuel Limestone - about 10% of the fuel Clinoptilolite - about 10% of the fuel Starch - about 3% of the total dry mass

The above ingredients are thoroughly blended into a dry mixture in the industrial blender. About 5% to 12% of water by mass of the compound is then added to, and blended into, the dry mixture thereby producing a wet mixture.

The wet mixture is then poured into moulds shaped to produce round disc-like pucks (described in greater detail below), and the wet mixture is compressed into such moulds at a pressure of about 20 metric tons per cubic cm. Or, it can be granulated, palletized, extruded, or disc formed into a solid.

The pucks are then dried at a temperature of at least 100 degrees centigrade for about 60 minutes.

Typically these pucks are made in a rounded disc-like shape having a dry mass of about 400 gram. Each puck has a diameter of about 140 mm, is about 25 to 55mm thick, and has a plurality of spaced-apart openings (each being about 12mm in diameter) extending through the body of the puck. Typically each puck

has about 30 of such holes to provide an increased ie enlarged surface for purposes of improved combustion.

These pucks may be used for heating and/or cooking purposes for example barbequeing, and may be simply ignited by placing a lighted match or cigarette lighter against or near the surface of the puck. Typically, once lit a puck having the above dimensions will burn for up to about 3 1/2 hours at a temperature of about 800 degrees Centigrade. A puck having smaller dimensions such as half the thickness ie 25 mm will burn for about 30 minutes (if made from anthracite). Consequently the burn-time will vary depending on the quality of the coal used in the briquette.

The inventor has found that, in another form of the invention, and as an alternative mixture, the addition of about 2% hexamine or about 2% Magnesium in powder form, by mass, provides an enlarged flare for improved initial ignition of the puck. A similar result may be achieved by adding an additional amount of charcoal and potassium nitrate to the mixture.

It will be seen from the above that no conventional (paraffin type) firelighter is required to ignite the puck. In other words the puck is ignitable without the aid of a conventional paraffin fire-lighter. This makes the puck more cost-effective to produce and use than conventional briquettes. In addition, the puck is clean- burning and does not smoke nor release other compounds once ignited, (i.e. like

tars and resins that can pollute ones food if used for direct cooking or foul an industrial furnace) causing less air pollution than existing briquettes. Lastly, the residue or ash remaining after the puck has burnt out contains fertilizing materials and can be used for gardening purposes.

The inventor has also found that these pucks are not dirty to handle, and are not friable nor prone to easy breakage. Example 2

In Example 1 above, during the blending step of the ingredients, a suitable amount of a liquid hydrocarbon, such as paraffin, or a bio fuel is added to the dry or wet mixture. The method is otherwise carried out as described above in the rest of Example 1.

The advantage of adding such an ingredient to the mixture is that this particular mixture can be used to provide pucks that are even more easily ignited than pucks as produced in Example 1.

Example 3

Pucks made in Example 1 are dipped or soaked briefly in a suitable liquid hydrocarbon, such as paraffin. This assists in the easier ignition of such pucks.

Example 4

The pucks described above are particularly suitable for heating and/or cooking of food such as for domestic or function barbeques. However, the heating means and method of the present invention may be adapted to be applied to commercial and/or industrial purposes.

In such applications, the finely ground dry mixture (about 200 micron or smaller) of Example 1 is produced but without the binder ie starch. This particular mixture can be used as a particulate fuel. This fine/pulverized mixture is pressure-fed through a particle burner and fired into a boiler or furnace, for example, to provide a relatively clean-burning fuel. This provides a useful heating means and method for industrial and commercial applications, using a waste product ie coal fines that would generally not be used for this or any other useful purpose.

The inventor has found that the present invention therefore offers various advantages over existing heating means or briquettes. These include the following:

(a) the pucks or pulverized fuel produced by this invention cost about half of the equivalent cost of paraffin to obtain the same amount of heat energy or heating;

(b) the pucks are not dirty to handle;

(c) the pucks are not friable nor prone to easy breakage;

(d) the pucks do not require paraffin-type fire-lighters to commence their ignition and thereby are more convenient and hence less expensive to use;

(e) the pucks and pulverized fuel emit less smoke and other compounds when ignited than conventional briquettes or coal, and hence cause less air pollution; and

(T) the residue or ash remaining after the pucks have burnt out can be used as a fertilizing material.

It appears to the inventor that, in use, the finely ground particles comprising the heating mixture contribute to quicker initial ignition, for example of a briquette or puck, and thereafter contribute to providing an improved and controlled environment for further efficient ignition and reaction, and hence contribute to reduced polluting emissions.

Accordingly, the invention in its various forms provides simplified and improved heating means, whether solid fuel elements or pulverized fuel and methods of

heating as compared to existing heating means, solid fuel elements or pulverized fuel and methods of heating.

Although the invention has been described above by way of certain examples only, it will be readily appreciated by any person skilled in the art that the present invention may include other examples, modifications, possibilities and variations. Such other examples, modifications, possibilities and variations are therefore to be considered as falling within the spirit and scope of the present invention as herein described and/or claimed.