EP1254946B1 - Chemical soot remover - Google Patents

Abstract

Solid product for the destruction of carbon deposits, e.g. soot, comprises a compressed aggregate of a particulate cellulosic solid and powder or crystals of a chemical destructive agent. The proportion of cellulosic substance is at least 30% and that of the chemical agent is at least 20%. Independent claims are also included for; (1) A method of preparation of the above product; and (2) A method of using the above product.

Description

The present invention relates to chemical sweeping products used in substitution or in addition to the mechanical chimney sweeping devices, as defined in the claims of claims 1 to 13.

In flues such as chimneys, the burning of organic compounds such as wood, coal, fuel, creates deposits that are usually called soot. The elimination of these deposits is mostly only mechanical and manual. This traditional sweeping technique involves passing brushes and hedgehogs through the chimney flues.

Soot removal can also be promoted by the use of chemical cleaning products.

Document FR-2,554,458 A, a solid fuel agent acting preventive or curative on deposits and soot in calorie generators, is particularly known. This agent comprises, inter alia, a particulate cellulosic combustible material, a preventive or curative active agent for soot and tarry deposits, and optionally a binder. The active product is in a small amount, less than 10%. The agglomerates obtained, for example in the form of briquettes, sticks or granules, are introduced into an active furnace at the rate of about 1 kg / ton of fuel. The effectiveness of the products thus formed is unsatisfactory, and in particular the destruction of soot is most often insufficient in sections of conduit away from the home, which are therefore at lower temperatures.

EP 0 837 121 A discloses a sweeping agent containing both a particulate solid cellulosic combustible material, a chemical and / or catalytic destructive agent of soot, and from 10 to 70% of a binder such as paraffin. The document recommends using such an agent in the absence of any other fuel and in an extinct household. The sweeping agent alone must ensure a combustion autonomy, and the presence of a combustible binder such as paraffin is essential for this. However, it is noted that such an agent does not have the effectiveness expected, probably because of the clogging effect of paraffin, because of the necessarily reduced amount of active agents, and because of the instructions for use that advocates an autonomous treatment in an extinct household. In particular, there is no effective sweeping action on the conduit sections away from the home, which are for this reason at a low temperature.

The problem proposed by the present invention is to design a more effective solid product for the more complete destruction of carbonaceous deposits such as soot, a process for its manufacture, and a method of use providing improved results.

In particular, it is sought to perform an effective sweeping action along the entire length of the flues, and in particular on the sections of ducts distant from the hearth, which are therefore at lower temperatures.

• constitué d'un agrégat mélangé et comprimé de matière combustible cellulosique solide particulaire et de poudre ou cristaux d'agent de destruction chimique des dépôts carbonés,
• la matière combustible cellulosique solide particulaire étant présente en proportion d'au moins 30 % en poids du produit,
• l'agent de destruction chimique des dépôts carbonés étant présent en proportion d'au moins 20 % en poids du produit.

To achieve these and other aims, the invention provides a solid product for the destruction of carbonaceous deposits such as soot:

• consisting of a mixed and compressed aggregate of particulate solid cellulosic fuel material and powder or crystals of agent for chemical destruction of carbonaceous deposits,
• the particulate solid cellulosic combustible material being present in a proportion of at least 30% by weight of the product,
• the chemical destruction agent of the carbonaceous deposits being present in a proportion of at least 20% by weight of the product.

In practice, the particulate solid cellulosic combustible material may be sawdust.

The chemical destruction agent of the carbonaceous deposits contains at least one ammonium salt and at least one alkali metal or alkaline earth metal salt.

The ammonium salt may advantageously be chosen from the family comprising ammonium sulphate, ammonium phosphate and ammonium chloride. However, it may be preferred to refrain from using ammonium chloride in order to avoid the release of chlorine or chlorinated products.

The ammonium salt is preferably ammonium sulfate.

A particularly improved sweeping efficiency, especially in cold areas of chimney flue, is obtained by using a chemical destruction agent of the carbonaceous deposits containing, in a mixture: an ammonium salt, potassium nitrate, and potassium carbonate .

In this case, the ammonium salt is present in the chemical destruction agent of the carbonaceous deposits in a proportion of greater than 50% by weight of the agent.

Potassium nitrate and potassium carbonate may be present in the chemical destructive agent in percentages adjacent to one another.

For example, the potassium nitrate may be present in a proportion of about 20% by weight, and the potassium carbonate may be present in a proportion of about 15% by weight of the chemical degrading agent of the carbonaceous deposits.

1. a) mélanger la matière combustible solide particulaire et l'agent de destruction chimique en poudre ou cristaux, selon les proportions en poids d'au moins 30 % de matière combustible solide particulaire et d'au moins 20 % d'agent de destruction chimique,
2. b) comprimer le mélange à une pression supérieure à 20.10⁵ Pa.

The invention further provides a method of manufacturing a solid product for destroying carbonaceous deposits as defined above, comprising the following steps:

1. a) mixing the particulate solid combustible material and the powdered or crystal chemical degrading agent, in the proportions by weight of at least 30% particulate solid fuel material and at least 20% chemical degrading agent,
2. b) compressing the mixture at a pressure greater than 20 × 10 ⁵ Pa.

To obtain a good aggregation and a sufficient cohesion of the product, during the manufacture of the product, the mixture must contain a reduced residual moisture content, corresponding to less than 15% of water approximately by weight, preferably less than 10% .

It is advantageous to use an alternative press having a tubular structure traversed by an axial piston and in which there is a chamber for receiving the upper orifice for introducing the mixture, an adjacent chamber for compression, and an axial outlet chamber. At the outlet of the press, the compressed product in the form of a continuous cylinder is cut to length by a saw.

1. 1) faire un feu dans la cheminée pour amener le conduit de cheminée à température voisine de la température habituelle de fonctionnement de la cheminée,
2. 2) constituer un lit de braises avec les résidus du feu,
3. 3) placer le produit solide sur le lit de braises, et laisser agir.

The invention also provides a use of a solid product for the destruction of carbonaceous deposits such as soot in a chimney, comprising the steps of:

1. 1) make a fire in the chimney to bring the flue to a temperature close to the usual operating temperature of the chimney,
2. 2) build a bed of embers with the residues of the fire,
3. 3) place the solid product on the bed of embers, and let act.

• la figure 1 illustre schématiquement en perspective un produit solide de destruction des dépôts carbonés selon un mode de réalisation de la présente invention, sous forme de bûche ;
• la figure 2 illustre l'utilisation du produit selon l'invention, pour le ramonage chimique d'une cheminée ;
• la figure 3 est une vue schématique illustrant les étapes du procédé de fabrication d'un produit selon l'invention ; et
• la figure 4 illustre schématiquement les étapes de fonctionnement de la presse pour la fabrication d'un produit solide selon l'invention.

Other objects, features and advantages of the present invention will become apparent from the following description of particular embodiments, with reference to the accompanying figures, in which:

• FIG. 1 schematically illustrates in perspective a solid product for destroying carbonaceous deposits according to one embodiment of the present invention, in the form of a log;
• FIG. 2 illustrates the use of the product according to the invention for the chemical sweeping of a chimney;
• Figure 3 is a schematic view illustrating the steps of the method of manufacturing a product according to the invention; and
• Figure 4 schematically illustrates the operating steps of the press for the manufacture of a solid product according to the invention.

The solid product for the destruction of carbonaceous deposits such as the soot according to the invention consists of a mixed and compressed aggregate of particulate solid cellulosic fuel material such as sawdust, and powders or crystals of a particulate agent. chemical destruction of carbonaceous deposits. In other words, the product according to the invention does not contain any other constituents, apart from the presence of water which is usual and inevitable in solid cellulosic materials such as sawdust and in the crystals of chemical destructive agent such as than the generally hygroscopic salts.

According to the invention, the particulate solid cellulosic fuel material is present in the product in a proportion of at least 30% by weight of the product, and the agent for chemical destruction of the carbonaceous deposits is present in a proportion of at least 20% by weight. product weight.

By the use of such a composition, the expected sweeping effects are optimized, thanks to a satisfactory quantity of active agents, and thanks to an increased duration of action by the slow combustion of the solid cellulosic combustible material alone. The combustion of the particulate solid cellulosic fuel material ensures the sublimation of the salts constituting the chemical destruction agent of the carbonaceous deposits, releasing slowly and for a long time active gases which destroy the carbonaceous deposits in the flue.

The solid product according to the invention may, for example, be packaged in the form of a log 1 as illustrated in FIG. 1, in which grains 2 of the particulate solid cellulosic combustible material and particles of powder or crystals can be distinguished. agent for chemical destruction of carbonaceous deposits.

The chemical destructive agent according to the invention contains at least one ammonium salt and at least one alkali metal or alkaline earth metal salt. The ammonium salt may be chosen from the family comprising ammonium sulphate (NH ₄ ) ₂ SO ₄ , ammonium phosphate (NH ₄ ) ₃ PO ₄ , and ammonium chloride NH ₄ Cl. however, ammonium sulphate, which has an improved action on soot and which avoids the release of chlorinated products which are both harmful and corrosive, is preferred.

An advantageous example of a chemical destructive agent according to the invention is a mixture containing an ammonium salt, potassium nitrate KNO ₃ and potassium carbonate K ₂ CO ₃ . In this case, the ammonium salt is present in the agent in a proportion greater than 50% by weight.

According to an advantageous example, the potassium nitrate and the potassium carbonate may be present in similar percentages, for example about 20% for potassium nitrate and about 15% for potassium carbonate, the percentages being expressed by weight chemical destruction agent.

• sulfate d'ammonium : 50 à 70 %
• nitrate de potassium : 15 à 30 %
• carbonate de potassium : 10 à 25 %
• acétate de nickel : 2 à 8 %

    pour un total de 100 % de l'agent de destruction chimique, les pourcentages étant exprimés en poids.An example of a particularly advantageous formulation of the chemical destructive agent is as follows:

• ammonium sulphate: 50 to 70%
• potassium nitrate: 15 to 30%
• Potassium carbonate: 10 to 25%
• nickel acetate: 2 to 8%

for a total of 100% of the chemical destructive agent, the percentages being expressed by weight.

This formulation optimizes the sweeping of the flue, by promoting a strong release of active gas at relatively low firing temperature, and promoting the chemical action on the soot in all areas of the flue and especially in the most cold.

Nickel acetate Ni (OCOCH ₃ ) ₂ catalyzes the action of salts on soot.

The use of the solid product according to the invention is illustrated in FIG. 2. There is shown a chimney 4 whose hearth 5 contains a bed of embers 6 supporting a log 1 according to the invention. A fire was previously made in the chimney 4 to bring the flue 8 to a temperature close to the usual operating temperature of the chimney. The embers bed 6 was formed with the residues of the fire. The solid product in the form of log 1 is placed on the embers bed 6. The reaction is then allowed to proceed: the heat released by the embers bed 6 causes the slow burning of the particulate solid cellulosic fuel material present in the solid product in the form of log 1, this combustion ensuring the maintenance of a sufficient temperature for the sublimation and release of gases 7 from the materials constituting the agent of chemical destruction. The gases 7 propagate in the duct 8, and act on the hot carbonaceous deposits such as soot present in the duct 8. The slow combustion of the log 1 can last several hours, allowing almost complete destruction of the carbonaceous deposits.

FIG. 3 illustrates the steps of a process for manufacturing a solid product for destroying carbonaceous deposits according to the invention. The method comprises the following steps.

In FIG. 3a, the particulate solid combustible material and the chemical destruction agent in powder or crystals are mixed in a container 9 by means of a mixing device 10.

In FIG. 3b, the mixture thus obtained is placed in a press 11 which compresses the mixture with the aid of a piston 12.

In FIG. 3c, the bar of compacted material thus obtained is cut to the appropriate length by means of a saw 13.

In Figure 4, there is illustrated more specifically the physical means of pressing for obtaining logs of product according to the invention. For this purpose, an alternative press essentially having a tubular structure 14 traversed by an axial piston 12 is used. In the tubular structure 14, a reception chamber 15 with an upper orifice 16 for introduction is distinguished from upstream to downstream. pre-formed mixture of particulate solid fuel material and chemical destructive agent. For example, the tubular structure 14 is oriented horizontally, and the upper insertion orifice 16 is oriented upwards, below a hopper 17.

Downstream of the receiving chamber 15, in the tubular structure 14, there is an adjacent compression chamber 18, followed by an axial outlet chamber 19.

Between the compression chamber 18 and the axial outlet chamber 19, there is a braking device 20, consisting for example of a radial jaw radially compressing a portion of material present in the tubular structure 14 to the right of the jaw, for braking the axial progression of the materials and allow compression by the piston 12 in the compression chamber 18.

In FIG. 4a, the device is in the initial state of receiving material in the reception chamber 15. The pre-mixed particulate matter enters the reception chamber 15 through the upper orifice 16 from the upper hopper 17. The piston 12 is then in the maximum recoil position.

In FIG. 4b, the piston 12 is advanced at high speed until it reaches the compression chamber 18. The material contained in the compression chamber 18 is then relatively compressed, and the compression is continued. advance of the piston 12. During this compression, the braking device 20 is biased radially inwards, to oppose the progression of the material towards the outlet chamber 19.

In FIG. 4c, the braking device 20 is released, and the piston 12 continues its stroke by pushing the section of compressed material towards the outlet chamber 19. The piston 12 then moves back to the position illustrated in FIG. 4a.

It will be understood that the alternative press thus formed makes it possible to produce successive sections of compressed and agglomerated material. The material continuously leaves the outlet chamber 19 in the form of a continuous bar, which can then be sawed by the saw 13 according to the appropriate lengths.

The joining of the successive compressed sections to form the continuous bar is ensured by the simple compression of the particulate material. However, this connection can be improved for successive sections by providing, on the piston head 21, a prominent central portion 22 which produces a differential thrust of the central portion of material relative to the peripheral portion.

The present invention is not limited to the embodiments which have been explicitly described, but it includes the various variants and generalizations thereof within the scope of the claims below.

Claims (13)

1. Solid chemical chimney cleaning product for the destruction of carbon-containing deposits such as soot,

   - consisting of a mixed and compressed aggregate of solid particulate cellulose-based combustible material and powder or crystals of an agent for the chemical destruction of the carbon-containing deposits,

   - the agent for the chemical destruction of the carbon-containing deposits containing at least one ammonium salt and at least one salt of an alkali or alkaline-earth metal,

   - the solid particulate cellulose-based combustible material being present in a proportion of at least 30% by weight of the product,

   - the agent for the chemical destruction of the carbon-containing deposits being present in a portion of at least 20% by weight of the product.
2. Product according to claim 1, characterized in that the solid particulate cellulose-based combustible material is sawdust.
3. Product according to either claim 1 or claim 2, characterized in that the ammonium salt is chosen from the family comprising ammonium sulphate, ammonium phosphate and ammonium chloride.
4. Product according to either claim 1 or claim 2, characterized in that the ammonium salt is ammonium sulphate.
5. Product according to either claim 1 or claim 2, characterized in that the agent for the chemical destruction of the carbon-containing deposits contains a mixture of an ammonium salt, potassium nitrate and potassium carbonate.
6. Product according to claim 5, characterized in that the ammonium salt is present in the agent for chemical destruction of carbon-containing deposits in a proportion greater than 50% by weight of the agent.
7. Product according to claim 6, characterized in that the potassium nitrate and the potassium carbonate are present in the chemical destruction agent in similar percentages.
8. Product according to claim 7, characterized in that the potassium nitrate is present in a proportion of approximately 20% and the potassium carbonate is present in a proportion of approximately 15% by weight of the agent for the chemical destruction of the carbon-containing deposits.
9. Product according to any one of claims 5 to 8, characterized in that the chemical destruction agent contains a mixture of :

   - 50 to 70% of ammonium sulphate,

   - 15 to 30% of potassium nitrate,

   - 10 to 25% of potassium carbonate,

   - 2 to 8% of nickel acetate,

   for a total of 100% by weight of the chemical destruction agent.
10. Method of fabrication of a solid chemical chimney cleaning product according to any one of claims 1 to 9 for the destruction of the carbon-containing deposits, characterized in that it comprises the following steps :

    a) mixing the solid particulate combustible material and the chemical destruction agent powder or crystals, in proportions by weight of at least 30% of solid particulate combustible material and at least 20% of chemical destruction agent,

    b) compressing the mixture at a pressure greater than 20.10⁵ Pa.
11. Method according to claim 10, characterized in that, during the fabrication of the product, the mixture contains less than 15% by weight of water.
12. Method according to either claim 10 or claim 11, characterized in that :

    - an alternating press is used having a tubular structure (14) through which passes an axial piston (12) and in which there are distinguished a reception chamber (15) with a top orifice (16) for introduction of the mixture, an adjacent compression chamber (18), and an axial outlet chamber (19),

    - at the outlet from the press, the compressed product in the form of a continuous cylinder is cut to appropriate length by a saw (13).
13. Use of a solid chemical chimney cleaning product according to any one of claims 1 to 9 for the destruction of carbon-containing deposits such as soot in a chimney (4), comprising the steps of :

    1) making a fire in the chimney (4) to heat the flue (8) of the chimney to a temperature close to the usual operating temperature of the chimney,

    2) constituting a bed of embers (6) with the residues of the fire,

    3) placing the solid product (1) on the bed of embers (6), and allowing it to act.

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