EP0837121A1 - Solid fuel for destroying soot and tars, method for making the same, and use thereof - Google Patents

Abstract

Solid combustible agent for destroying soot and in particular tar deposits in the smoke ducts, said agent comprising in mixture a particulate solid cellulosic combustible material, a chemical agent and / or catalytic soot destroyer and a binder. The destruction of soot and tarry deposits is obtained by the combustion of the solid combustible agent in the hearth. Use of the combustible agent in the form of logs.

Description

The present invention relates to chemical sweeping and / or catalytic of combustion devices and conduits smoke. It relates more particularly to a combustible agent solid chemical and / or catalytic destruction of the soot, its manufacturing process and its use.

By "soot" in the present description means the deposits of all kinds that form in the devices of heating and more particularly in the flues. These deposits can be of various nature, in particular particles carbonaceous matter, entrained ashes and above all tars. These are mainly deposited in the lower part of the flues. Training and filing of these materials are particularly emphasized in the case from burning solid fuels such as coal and wood, especially with closed hearths or "inserts".

The accumulation of these materials and in particular tar in chimneys is dangerous because these materials are flammable and cause chimney fires. They are also at the origin of the bad draft of the chimneys and apparatuses because they narrow the section of ducts. A traditional sweeping with a hedgehog cannot overcoming the tars which form a hard, stuck crust to the walls of the duct so that even after mechanical sweeping traditional, the risk of chimney fire persists.

Chimney sweeping products are currently on the market called "chemical" or "catalytic". Some of these products contain sulfur to decompose tar to facilitate their combustion with all the risks that this involves, in particular the risk of a chimney fire, because it is necessary heat the duct to the maximum to make the product effective, and the risk of deterioration of the conduits by caustic soda or its decomposition products.

Scientific literature and patents list many other chemical or catalytic agents intended for prevent deposits from forming in ovens and chimneys or even destroy these deposits once they have been formed, but these agents are most often of an impractical use, especially when presented in liquid form or in powder form. Liquid agents require nozzles injection and their use can therefore not be considered with domestic heaters; as for powdered agents, their use is delicate because it is necessary to add a powder in more or less precise dosage on a more or less sustained fire, very difficult to measure and control. Furthermore a large part of the powder or its decomposition products is entrained in the atmosphere, which represents a loss and pollution risks.

Document FR-A-2 554 458 describes a combustible agent solid acting preventively or curatively on deposits and soot in the calorie generators. This agent can understand, among others, a combustible cellulosic material particulate, an active preventive or curative agent for soot and tar deposits and optionally a binder. The agglomerates obtained, for example in the form of briquettes, sticks or granules are introduced into an active hearth, about one kilogram per tonne of fuel, the agglomerate containing a few grams or tens of grams of anti-soot agent per kilogram of agglomerate.

The use of paraffin wax as a binder for materials in the manufacture of fire starters and artificial logs is known from documents US-A-4 147 518 and US-A-3,297,419 respectively. This last document provides incorporate organometallic additives into artificial logs, in proportion less than 0.1% and whose effect is improve the terminal combustion of logs, or nitrates at a rate of 5% by weight to simulate the crunches produced by an actual wooden log. There is no suggestion an effect on chimney sweeping.

Document US-A-3,637,355 also describes logs artificial sawdust and paraffin wax. These logs contain flame dyes, including metal salts in minimal proportion, of the order of 1 to 2% in The example. Nothing is indicated regarding a possible chimney sweeping.

The aforementioned drawbacks of chimney sweepers known are reduced or eliminated by the use of the solid agent soot destruction, or chimney sweeping agent, of the invention, and by the preferred mode of its implementation.

The invention is based on the new concept of realizing a combustible solid mass incorporating a destructive agent soot and especially tar. The combustion of this mass allows the soot-destroying agent to volatilize as it burns and come to contact with soot and tar.

a) une matière combustible cellulosique solide particulaire,

b) un agent chimique et/ou catalytique destructeur de suie,

et c) un liant.

The chimney sweeping agent of the invention therefore consists of a solid aggregate containing, as essential constituents:

a) a particulate solid cellulosic combustible material,

b) a soot-destroying chemical and / or catalytic agent,

and c) a binder.

Preferably the above components are found in substantially homogeneous mixture, although one can envisage, for example, the use of successive layers of elements (a) and (b) linked by element (c), or a surface coating final mixing by the only component (c) or (a) or the mixture (c + a), for example to accelerate inflammation. We can also put the entire component (b) in the center or in the central axis of the composition.

• il est "autonome", c'est-à-dire qu'il n'est plus besoin de faire un feu séparé et d'y ajouter une bûche artificielle ou une poudre en dosage mal réglé ; il est donc beaucoup plus facile à utiliser par n'importe quel utilisateur en toute sécurité et fiabilité, particulièrement dans les cheminées fortement encrassées,
• il est également plus performant en ce sens que le dégagement du produit actif va se poursuivre de manière régulière tout au long de la combustion ce qui donne à ce produit actif un temps suffisant pour traiter les goudrons, la combustion de l'agent de ramonage amenant les goudrons à une température permettant de les traiter de manière efficace. Le ramonage est donc obtenu plus rapidement que par emploi des techniques chimiques et/ou catalytiques connues.

The sweeping agent of the invention has several advantages over the sweeping agents of the prior art, and in particular the following:

• it is "autonomous", that is to say there is no longer any need to make a separate fire and to add an artificial log or a powder in the wrongly adjusted dosage; it is therefore much easier to use by any user in complete safety and reliability, particularly in heavily fouled chimneys,
• it is also more efficient in the sense that the release of the active product will continue regularly throughout the combustion, which gives this active product sufficient time to treat the tars, the combustion of the sweeping agent bringing tars at a temperature that allows them to be treated effectively. Chimney sweeping is therefore obtained more quickly than by using known chemical and / or catalytic techniques.

Particulate solid cellulosic combustible material preferably consists of wood particles, for example in the form of sawdust, flour, chips, fibers or the like. However, other combustible materials can be used cellulosic, for example grinding or chopping products cereal straw, crushed and dried residue from certain household waste (plant residues) or residues pulp mills. The particle size is advantageously between 0.1 and 10 mm for sawdust and wood flour. Other materials are longer (chips or fibers) but their thickness is then preferably understood between 0.1 and 2 mm.

• un mélange de nitrate de potassium et de sulfate d'ammonium (1 : 10 à 10 : 1 en poids),
• un mélange de sulfate d'ammonium et de chlorure de magnésium (2 : 10 à 10 : 2 en poids),
• un mélange de phosphate dicalcique, de chlorure d'ammonium, de sulfate de fer et de nitrate de calcium,
• un mélange de phosphate d'ammonium, de sulfate d'ammonium et de nitrate de cuivre,
• un mélange d'acétate de potassium et de nitrate de magnésium.

The soot-destroying chemical agent and / or catalytic agent and in particular tar can be any of the agents used for this purpose and which can be found in numerous examples in the scientific literature and patents. Mention will be made, without this list being exhaustive, of ammonium salts such as chloride, nitrate, acetate or ammonium sulfate, acetates and nitrates of potassium and / or magnesium, phosphates such as phosphates of ammonium and the phosphates of alkali and alkaline earth metals, carbonates, oxides and hydroxides of alkali and alkaline earth metals, for example those of sodium, potassium, calcium and ammonium. Compounds of polyvalent metals such as copper, manganese, iron and cerium can have a catalytic effect and are therefore useful in the invention, for example in an amount of 0.1 to 2% by weight. These various compounds can be used alone or in mixtures. Examples include:

• a mixture of potassium nitrate and ammonium sulphate (1: 10 to 10: 1 by weight),
• a mixture of ammonium sulfate and magnesium chloride (2: 10 to 10: 2 by weight),
• a mixture of dicalcium phosphate, ammonium chloride, iron sulphate and calcium nitrate,
• a mixture of ammonium phosphate, ammonium sulfate and copper nitrate,
• a mixture of potassium acetate and magnesium nitrate.

Superior results have been obtained with a mixture of P ₂ O ₅ or phosphoric acid and an ammonium salt, in particular a mixture of phosphorus pentoxide and an ammonium salt at a rate of 10-90% by weight of one for 90-10% by weight of the other, for example a mixture of phosphorus pentoxide and ammonium sulfate (1: 10 to 10: 1 by weight) with or without the addition of a composed of copper or manganese.

The mechanism of action of the soot-destroying agent and of tars [element (b) of the invention] depends to some extent measure of the agent chosen, but, regardless of this agent, its mechanism of action is still poorly understood. What is found is that these agents facilitate the conversion of tar deposits in powdery and poorly adherent ash which detach more easily. Ammonium salts vaporize easily and serve as coaches for other compounds minerals present. However, they also have their own action disaggregation of deposits.

We therefore think that the mechanism is mainly chemical but that metals or metal compounds possibly present, such as those of iron, copper or manganese, can have a catalytic action.

The above explanations should not be considered as limiting the invention in any way is.

The binder is any material capable of maintaining the cohesion of the mixture of elements (a) and (b). The preference is given to a solid paraffin wax at room temperature. Indeed paraffin is a combustible material by wicking and which, in the molten state, can permeate the elements (a) and (b) and, after cooling, maintains good cohesion between these elements in the solid obtained. We prefer a paraffin which melts above 40 ° C. However, we can also use a natural, artificial or synthetic glue, and for example a vinyl adhesive, a thermoplastic resin, a starchy material, stearic acid.

The relative proportions of the elements (a, b and c) can vary widely depending in particular on the nature of each of the elements of the composition, their porosity, their combustibility and, for the soot-destroying agent, of its effectiveness.

In most cases, the relative weight proportions will be 20 to 80% of (a), 10 to 40% of (b) and 10 to 70% of (c) per 100 parts of the mixture (a + b + c). Subjects additional may be present, either as thinners, for example silica and silicates, either as combustion additives, either as aesthetic modifiers, for example a dye or a pigment, or to any other end. Their weight proportion will not exceed half of the proportion of (a + b + c) and will preferably remain less than 10% and, better, less than 5% of this proportion.

(a) : 25 à 45 % en poids

(b) : 15 à 30 % en poids

(c) : 40 à 65 % en poids, le tout ramené à 100 parties de (a + b + c).

However, the following proportions are preferred:

(a): 25 to 45% by weight

(b): 15 to 30% by weight

(c): 40 to 65% by weight, the whole reduced to 100 parts of (a + b + c).

The combustible agent for destroying soot according to the invention can be presented in any desired form, either regular, for example cubes, cylinders, any polygons, spheres, either in random form. In the case of homes normally using wood, we prefer a log form or log both more aesthetic and more practical. The dimensions of the log or log may be any and preferably will be approximately those of the logs of wood usually used in the hearth, corresponding to the more often at a length of 10 to 40 cm.

The method of manufacturing the aggregates of the invention may be of the same type as that conventionally used in the manufacture of a log in sawdust and paraffin or in making a simply compressed log, unlike close that the combustible material (a) is added anti-soot agent (b) before sizing or coating with the agent (c) or during it. The mixture obtained (a + b + c) can be press molded or extruded, or cast in mussels. If the binder is used as a solution or dispersion in a solvent, this is removed by evaporation or drying. We prefer that the elements of the aggregate are distributed substantially homogeneously, although we can also arrange the agent (b) in the center or in successive layers.

The aggregate, for example the log, obtained can then, if desired, be wrapped in an envelope preferably fuel that will facilitate inflammation, for example paper, cardboard or waxed or treated paper or cardboard to facilitate its ignition.

Example

400 parts by weight are mixed at the temperature of 80 ° C. dry sawdust with an average particle size of 1 mm with 200 parts by weight of a mixture in equal parts by weight of ammonium sulfate and phosphorus pentoxide and 600 parts by weight of molten paraffin. After partial cooling to at least partially solidify the paraffin, the mixing and cutting pieces of extrudates of a length about 30 cm, the average diameter being about 12 to 15 cm. These pieces have the appearance of logs. We pack these logs in paper bags, which is however not essential.

We place a log of this type in a wood fireplace, previously extinguished and whose chimney requires sweeping and we ignite this log. The log burns with flame for about 30 minutes to 2 hours depending on its size, and gives off heat which heats the chimney and softens the deposits, while the active product begins to treat the chimney. Then the log continues to burn slowly while giving off a slow smoke which can last, for example, from 2 to 6 hours. The action of the active product continues and we can then see that the deposits in the chimney have been greatly reduced, otherwise removed, or have been made crumbly which allows them easy detachment. In the case of very dirty chimneys, the treatment can be renewed.

So in a few hours you get an equal result or higher than that obtained in 8 to 10 days of treatment with commercial powders.

It should be noted that there is no need to put the log in an already lit and maintained fireplace. Everything at otherwise the best results are obtained in the absence of any other fuel.

Good results have also been obtained with a mixture of ammonium sulfate and potassium chloride (40/60 by weight) as well as with a mixture of potassium acetate and ammonium sulphate (30/70 by weight) with or without addition of copper nitrate.

Claims (19)

Solid combustible agent for destroying soot, and in particular tar deposits, consisting of a solid aggregate containing, as essential constituents: a) a particulate solid cellulosic combustible material, b) a chemical and / or catalytic agent destructive of soot and in particular of tarry deposits and c) a binder, characterized in that the relative proportions of said essential constituents are, by weight, from 20 to 80% of a), from 10 to 40% of b) and from 10 to 70% of c) per 100 parts of (a + b + vs). The agent of claim 1, wherein the relative proportions are, by weight, from 25 to 45% of a), of 15 to 30% of b) and 40 to 65% of c) for 100 parts of (a + b + c). Agent according to claim 1 or 2, present under the shape of a log with a preferred length of 10 to 40 cm. Agent according to one of claims 1 to 3, present in the form of a log of a size corresponding to a autonomous burning time with flame from 30 minutes to 2 hours. Agent according to one of claims 1 to 4, in which the particulate solid combustible material a) is made of wood particles and the binder c) is of the paraffin wax, glue, thermoplastic resin, a starchy material or stearic acid. Agent according to one of claims 1 to 5, in which agent b) contains an ammonium salt. Agent according to one of claims 1 to 6, in which agent b) comprises phosphorus pentoxide or phosphoric acid and an ammonium salt. Agent according to one of claims 1 to 7, in which agent b) is a mixture of phosphorus pentoxide and an ammonium salt in an amount of 10-90% by weight of one for 90-10% by weight of the other. The agent of claim 8, wherein the salt ammonium is ammonium sulfate. Agent according to one of claims 1 to 6, in which agent b) contains ammonium phosphate. Process for manufacturing the agent of any one claims 1 to 10, characterized in that mix components a), b) and c) in the proportions indicated, homogeneously or heterogeneously and in that the resulting mixture is shaped. Method according to claim 11, characterized in what component c) is paraffin wax and in that that the mixing is carried out with the molten paraffin wax, this mixture being followed by cooling at least partial, to solidify at least partially the wax of paraffin, and extruding the mixture. Use of a soot-destroying agent and in particular of tarry deposits from combustion appliances and smoke ducts of a fireplace, said use comprising the installation in the fireplace, which is not already lit and maintained, a solid combustible agent consisting of a solid aggregate containing, as essential constituents, a) a particulate solid cellulosic combustible material, b) a chemical and / or catalytic agent destructive of soot and in particular of tarry deposits and c) a binder, and the ignition and combustion of said agent in said focus. Use according to claim 13, in which the solid combustible agent which contains the constituents a), b) and c) is in the form of a log and constitutes the only combustible material present in the hearth, the proportions respective weight of the constituents being from 20 to 80% of a), 10 to 40% of b) and 10 to 70% of c) for 100 parts of (a + b + c). Use according to claim 13 or 14 in which the binder is paraffin wax, an adhesive, a thermoplastic resin, a starchy material or stearic acid. Use according to one of claims 13 to 15, in which the solid combustible agent is as defined in claim 2. Use according to one of claims 13 to 16, in which component b) comprises pentoxide of phosphorus or phosphoric acid and an ammonium salt. Use according to one of claims 13 to 16, in which component b) comprises phosphate or ammonium sulfate. Solid combustible agent for destroying soot, and in particular tar deposits, in the form of a log, comprising a chemical and / or catalytic agent destructive of soot, characterized in that it contains, as essential constituents: a) a particulate cellulosic combustible material consisting of wood particles, b) a soot-destroying chemical and / or catalytic agent consisting of sulphate, phosphate or ammonium acetate, and c) a binder.