EP0007862A1 - Liquid agent for the chemical destruction of soot and method of application - Google Patents
Liquid agent for the chemical destruction of soot and method of application Download PDFInfo
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- EP0007862A1 EP0007862A1 EP79400514A EP79400514A EP0007862A1 EP 0007862 A1 EP0007862 A1 EP 0007862A1 EP 79400514 A EP79400514 A EP 79400514A EP 79400514 A EP79400514 A EP 79400514A EP 0007862 A1 EP0007862 A1 EP 0007862A1
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- Prior art keywords
- magnesium
- potassium
- acetate
- atoms
- agent
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Classifications
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
- C10L10/00—Use of additives to fuels or fires for particular purposes
- C10L10/06—Use of additives to fuels or fires for particular purposes for facilitating soot removal
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
- C10L1/00—Liquid carbonaceous fuels
- C10L1/10—Liquid carbonaceous fuels containing additives
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
- F23J7/00—Arrangement of devices for supplying chemicals to fire
Definitions
- the present invention relates to the chemical sweeping of ovens and boilers of all types and flues.
- soot designates unburnt carbon and that the term “deposits” as used below designates a mixture deposited on the surfaces and consisting of soot, fuel ash containing in particular iron sulphates and oxides of metals, corrosion products, etc.
- Chloride-based products have been used, for example, which lower the ignition point of carbon, but which present a fire risk and above all a risk of corrosion by the hydrochloric acid which is released as a result of the reaction of chlorides with sulfuric anhydride retained in soot and coming from the sulfur which the majority of the fuels contain.
- U.S. Patent 2,949,008 relates to a chemical agent containing a magnesium compound and an alkali metal compound and which can be applied in the form of an aqueous solution, but this agent is intended not to chemically destroy the soot, but to reduce corrosion of the soot.
- a known chemical chimney sweeping age is a mixture, in powder form, of potassium nitrate in high proportion and of sulfur and charcoal in low proportion.
- the pulverulent mixture is injected with compressed air and burned in the flame of the burner of the oven or of the boiler at a temperature above 450 ° C., the combustion of this mixture causing, with a significant release of heat, the formation of 'A complex gas, containing in particular carbon dioxide and sulfuric anhydride, and very fine solid particles consisting essentially of potassium carbonate, but also potassium sulfate and potassium oxide, among others.
- the potassium carbonate has an effect of lowering the ignition point of the carbon of the soot and an oxidation effect of this carbon, which is destroyed from 130 ° C by transformation into carbonic gas (it is a combustion slow catalytic), while potassium oxide partially neutralizes the acidic sulfur derivatives retained in the deposits.
- Chimney sweeps and blowing become unnecessary and it suffices to periodically remove by suction the deposits, which are no longer made up of powdery and poorly adherent ash, containing in particular iron sulphates and metal oxides from the fuel.
- this chimney sweeping agent presents several difficulties: in fact, the powder of said mixture melts at 140 ° C.
- the object of the present invention is to remedy the great difficulty of applying, in practice, this chemical agent chimney sweep.
- This agent which is an aqueous solution of an alkali metal compound and a magnesium compound, is characterized in that the alkali metal compound is potassium acetate, CH 3 Co 2 K, in that the compound of magnesium is magnesium nitrate, (N0 3 ) 2 Mg, or a mixture of magnesium nitrate and magnesium acetate, (CH 3 C0 2 ) 2 M g , and in that the relative proportions of potassium and magnesium in the agent are 40 to 60 atoms of the first for 60 to 40 atoms of the second.
- said solution can contain 56 potassium atoms for 44 magnesium atoms.
- the proportion of water is variable, the most suitable dilution being able to be easily determined experimentally in each particular case of use.
- the solution initially prepared and delivered to users is a saturated solution, to reduce congestion during storage and transport.
- potassium acetate it is possible to replace potassium acetate with a chemical equivalent in the form of a water-soluble salt of an alkaline earth metal in place of potassium and / or an organic acid other than acid acetic, but, like the latter, usual and inexpensive, such as formic acid or butyric acid.
- alkali and / or alkaline earth silicates can be added to the liquid agent in question, for example in the form of a saturated aqueous solution added to the saturated aqueous solution of the agent.
- a saturated aqueous solution added to the saturated aqueous solution of the agent.
- silicates makes it possible to raise the melting point of these ashes, consequently, to make them "dry", non-adherent and therefore easily removable, and less corrosive, when they contain corrosive substances such as vanadium. , which may be the case when they result from the combustion of fuel oil.
- the proportion of silicates can be from 5 to 10% by weight relative to the weight of the agent.
- the liquid chemical sweeping agent according to the invention is easy to spray into the flame of the burner of an oven or a boiler by means of compressed air, or better still by means of an electric vibrator. There is no exothermic reaction which may cause an explosion.
- the water evaporates as soon as the solution reaches 100 ° C, a temperature which it is useless to exceed.
- the dry extract then ignites very quickly, it is broken down into its elements, and the free potassium and magnesium ions generate, in the oxidizing atmosphere of the flame reinforced by the oxidizing nitrate ions, on the one hand, potassium oxide (R20), which transforms into powdered potassium carbonate (CO 3 K 2 ), in the presence of the carbon dioxide of the combustion gases, to which is added that resulting from the subsequent oxidation of the soot by this carbonate, and, on the other hand, magnesium oxide (MgO) also in the pulverulent state.
- the potassium carbonate ensures the catalytic combustion of the soot present in the combustion gases and on the surfaces, in the manner indicated above, by lowering the ignition point of carbon and by an effect of carbon oxidation.
- the powdery potassium carbonate which is added to the deposits, does not adhere to the walls and is easily removable.
- magnesium oxide it neutralizes the sulfur oxidation products retained by the deposits as well as the sulfuric acid condensed in the cold areas of the furnace or the boiler, whereas with the previous chemical xamonage agents, it was generally necessary to carry out a complementary treatment, consisting in spraying in these cold areas very fine magnesium oxide, in particular of a size less than 10 microns, which was not an easy operation; with the new chemical sweeping agent, MgO is formed in situ. Since potassium carbonate is basic, it cooperates with MgO for the neutralizing action.
- the magnesium sulphate and potassium sulphate formed are powdery, non-adherent, easily removable products.
- the ratio between the number of potassium atoms and the number of nitrate ions (NO 3 - ) in the present agent is 1.87, this which corresponds to 56 potassium atoms for 30 nitrate ions.
- this preferred K / NO 3 ratio of 1.87 is to optimize the combustion of the dry extract obtained after evaporation of the water, when said agent is used.
- NO 3 ion content is greater than 30 ions, there is a risk of formation of toxic nitrogen oxides, NO x , as well as products such as nitrites which can be found on the surfaces of the oven or the boiler and flues, in the molten state and inactive, also resulting in a loss of agent efficiency.
- magnesium can no longer, in this case, be present in the agent only in the form of nitrate, if the ratio is to be maintained preferential K / Mg of 56 atoms of the first for 44 atoms of the second.
- the magnesium supplement is then provided in the form of magnesium acetate.
- the improved liquid agent according to the present invention is characterized in that the magnesium compound which it contains is a mixture of magnesium nitrate, (N0 3 ) 2 Mg, and magnesium acetate, (CH 3 C0 2 ) 2 Mg, in the preferred proportions of 15 molecules of nitrate for 29 molecules of acetate.
- the subject of the invention is also the method of applying said agent, consisting in spraying it into the flame by means of an electric vibrator, which makes it much better than air. tablet, control the injection.
- an electric vibrator which makes it much better than air. tablet, control the injection.
- the latter can be either a solid fuel (coal, wood, shale, lignite, for example), liquid (oil), or gas.
- the liquid form of the agent and its spraying ensure optimum fine distribution and maximum effectiveness of the agent.
- the sulfur dioxide content (SO 3 ) of the deposits is usually analyzed when chemical sweeping is carried out; this anhydride having to be currently neutralized by magnesium oxide, account is taken of the results of said analysis to introduce magnesium nitrate and optionally magnesium acetate in greater or lesser proportions into the chemical sweeping agent considered, and the agent injection rate or the frequency of its injection are also determined by this analysis as well as, of course, by the extent of the deposits.
- the injections were periodic, with the new liquid agent, spraying in the flame can be carried out continuously and it has an anti-pollution effect continuously of the atmosphere and anti-corrosion of the equipment.
- Another object of the invention is the process for the preparation of the new chemical chimney sweeping agent considered.
- This process consists in preparing a saturated aqueous solution of potassium acetate and optionally magnesium acetate, from acetic acid and, respectively, potassium carbonate and magnesium carbonate, in stoichiometric proportions, then preparing a saturated aqueous solution of magnesium nitrate, starting from nitric acid and magnesium carbonate in stoichiometric proportions, all these preparations being carried out individually under cooling, after which the saturated solutions are mixed so that the ratio of potassium to magnesium in the mixture of 40 to 60 atoms of the first for 60 to 40 atoms of the second and diluted with water in a variable manner, at the time of use, the concentrated intermediate mixture thus obtained, the most favorable dilution being determined experimentally in each case of use of the final solution.
- the mixing is preferably carried out so that it contains 56 potassium atoms for 44 magnesium atoms and, when we want to obtain the optimal ratio of 1.87 between the number of potassium atoms and the number of nitrate ions, so that it contains, for 56 molecules of potassium acetate, 15 molecules of magnesium nitrate and 29 molecules of magnesium acetate.
- silicates can be added to the solution, as indicated above.
- potassium acetate could be replaced by an acetate of an alkaline earth metal, in which case the raw material potassium carbonate is replaced by the corresponding carbonate, and that the acetate anion could be replaced by a another anion, in which case the raw material acetic acid is replaced by another organic acid which is easy to obtain and inexpensive.
- potassium magnesium acetates and magnesium nitrate potassium hydroxide, KOH, and magnesia, MgO, can also be used instead of potassium carbonate and magnesium carbonate, respectively. Stoichiometric proportions of these bases and of acetic and nitric acids are also used.
- the agent according to the invention can be prepared in the following manner: under cooling, successively and in stoichiometric proportions are poured into the total amount of water necessary to obtain a saturated solution in the desired amounts of the various constituents, acetic acid, potassium carbonate or potash necessary to form potassium acetate, magnesium carbonate or magnesia necessary to form magnesium acetate, nitric acid, magnesium carbonate or magnesia necessary to form magnesium nitrate, then dilute with water, at the time of use, the concentrated solution obtained, the most favorable dilution being determined experimentally in each case of use of the final solution.
- the necessary cooling during the preparation of the agent can be obtained by circulating cold water in the reaction medium (for example by means of an immersed coil), or around this medium; for example, the preparation can be carried out in a jacketed container and a circulation of cooling water can be established in the container jacket.
- composition of the agent according to the invention is given below, but it is in no way limiting
- the preparation of the product can be carried out according to the method indicated above as an alternative, that is to say by successively adding and under cooling, in the 69.5 parts of water, the quantity of acetic acid necessary to form 14.5 parts of potassium acetate and 10.1 parts of magnesium acetate, the amount of potassium carbonate required to form 14.5 parts of potassium acetate, the amount of magnesium carbonate required to form 10.1 parts of magnesium acetate, the amount of nitric acid required to form 5.9 parts of magnesium nitrate, and the amount of magnesium carbonate required to form 5.9 parts of magnesium nitrate.
- This concentrated solution will be diluted variably at the time of use and depending on the use.
- potassium carbonate and the magnesium carbonate can be replaced, as mentioned above, by potash and magnesia.
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Abstract
Description
La présente invention concerne le ramonage chimique des fours et chaudières de tous types et des conduits de fumée.The present invention relates to the chemical sweeping of ovens and boilers of all types and flues.
Il est bien connu que la combustion des combustibles, solides, liquides et gazeux laisse un dépôt de carbone imbrûlé ou suie sur les surfaces intérieures des fours, chaudières et conduits de fumée et que cette suie constitue un revêtement calorifuge nuisible au bon transfert thermique et accroissant, par conséquent, la consommation d'énergie, d'où la nécessité des ramonages à la vapeur d'eau ou des soufflages à l'air comprimé. Or, ces procédés ont l'inconvénient évident de polluer l'atmosphère et ils sont donc néfastes.It is well known that the combustion of fuels, solids, liquids and gases leaves a deposit of unburnt carbon or soot on the interior surfaces of ovens, boilers and flues and that this soot constitutes a heat-insulating coating detrimental to good thermal transfer and increasing , therefore, energy consumption, hence the need for sweeping with steam or blowing with compressed air. However, these methods have the obvious disadvantage of polluting the atmosphere and they are therefore harmful.
Il convient de préciser que le terme "suie" désigne le carbone imbrûlé et que le terme "dépôts" tel qu'utilisé ci-après désigne un mélange déposé sur les surfaces et constitué de suie, de cendres du combustible contenant notamment des sulfates de fer et des oxydes de métaux, de produits de corrosion, etc...It should be specified that the term "soot" designates unburnt carbon and that the term "deposits" as used below designates a mixture deposited on the surfaces and consisting of soot, fuel ash containing in particular iron sulphates and oxides of metals, corrosion products, etc.
On a déjà proposé des agents de ramonage chimique, destinés à éviter la pollution atmosphérique. On a utilisé, par exemple, des produits à base de chlorures, qui abaissent le point d'ignition du carbone, mais qui présentent des risques d'incendie et surtout des risques de corrosion par l'acide chlorhydrique qui est libéré, par suite de la réaction des chlorures avec l'anhydride sulfurique retenu dans la suie et provenant du soufre que contiennent la plupart des combustibles.Chimney sweeping agents have already been proposed, intended to avoid atmospheric pollution. Chloride-based products have been used, for example, which lower the ignition point of carbon, but which present a fire risk and above all a risk of corrosion by the hydrochloric acid which is released as a result of the reaction of chlorides with sulfuric anhydride retained in soot and coming from the sulfur which the majority of the fuels contain.
Le brevet américain 2 949 008 concerne un agent chimique contenant un composé de magnésium et un composé de métal alcalin et pouvant être appliqué sous forme de solution aqueuse, mais cet agent est destiné non pas à détruire chimiquement la suie, mais à réduire la corrosion des parties métalliques par les cendres contenant du vanadium, qui résultent de la combustion de combustibles pétroliers résiduaires contenant du vanadium ; il ne s'agit donc pas d'un agent de ramonage.U.S. Patent 2,949,008 relates to a chemical agent containing a magnesium compound and an alkali metal compound and which can be applied in the form of an aqueous solution, but this agent is intended not to chemically destroy the soot, but to reduce corrosion of the soot. metallic parts from ash containing vanadium, which result from the combustion of waste petroleum fuels containing vanadium; It's not about so no chimney sweeper.
Un ageht chimique de ramonage connu est un mélange, sous forme de poudre, de nitrate de potassium en forte proportion et de soufre et de charbon de bois en faibles proportions. On injecte à l'air comprimé et fait brûler le mélange pulvérulent dans la flamme du brûleur du four ou de la chaudière à une température supérieure à 450°C, la combustion de ce mélange engendrant, avec un dégagement de chaleur important, la formation d'un gaz complexe, contenant notamment de l'anhydride carbonique et de l'anhydride sulfurique, et de particules solides très fines constituées essentiellement de carbonate de potassium, mais aussi de sulfate de potassium et d'oxyde de potassium, entre autres. Le carbonate de potassium a un effet d'abaissement du point d'ignition du carbone des suies et un effet d'oxydation de ce carbone, qui est détruit dès 130°C par transformation en gaz carbonique (il s'agit d'une combustion lente catalytique), tandis que l'oxyde de potassium neutralise partiellement les dérivés acides du soufre retenus dans les dépôts. Les ramonages et les soufflages deviennent inutiles et il suffit d'éliminer périodiquement par aspiration les dépôts, qui ne sont plus constitués que de cendres pulvérulentes et peu adhérentes, contenant notamment des sulfates de fer et les oxydes des métaux provenant du combustible. Cependant, l'utilisation convenable de cet agent chimique de ramonage présente plusieurs difficultés : en effet, la poudre dudit mélange fond à 140°C et il faut parvenir à l'injecter dans la flamme du brûleur sans qu'elle fonde, sinon,par suite du bouchage du tube d'injection, il peut se produire une explosion il faut donc déterminer, dans chaque cas particulier, la vitesse d'injection appropriée évitant la fusion de la poudre et il faut, dans ce but, étudier la combinaison de mouvements, à laquelle est soumise la poudre injectée (mouvement linéaire de l'injection initiale et mouvement de rotation de l'air comprimé, chargé de la poudre, dans la flamme du brûleur). De plus, la nécessité, en fait, d'une température de combustion,de la poudre d'au moins 450°C peut limiter l'efficacité dans les foyers n'atteignant pas cette température.A known chemical chimney sweeping age is a mixture, in powder form, of potassium nitrate in high proportion and of sulfur and charcoal in low proportion. The pulverulent mixture is injected with compressed air and burned in the flame of the burner of the oven or of the boiler at a temperature above 450 ° C., the combustion of this mixture causing, with a significant release of heat, the formation of 'A complex gas, containing in particular carbon dioxide and sulfuric anhydride, and very fine solid particles consisting essentially of potassium carbonate, but also potassium sulfate and potassium oxide, among others. The potassium carbonate has an effect of lowering the ignition point of the carbon of the soot and an oxidation effect of this carbon, which is destroyed from 130 ° C by transformation into carbonic gas (it is a combustion slow catalytic), while potassium oxide partially neutralizes the acidic sulfur derivatives retained in the deposits. Chimney sweeps and blowing become unnecessary and it suffices to periodically remove by suction the deposits, which are no longer made up of powdery and poorly adherent ash, containing in particular iron sulphates and metal oxides from the fuel. However, the proper use of this chimney sweeping agent presents several difficulties: in fact, the powder of said mixture melts at 140 ° C. and it is necessary to inject it into the flame of the burner without it melting, otherwise, by as a result of the plugging of the injection tube, an explosion may occur, it is therefore necessary to determine, in each particular case, the appropriate injection speed avoiding the melting of the powder and it is therefore necessary to study the combination of movements , to which the injected powder is subjected (linear movement of the initial injection and rotational movement of the compressed air, charged with the powder, in the flame of the burner). In addition, the need, in fact, for a combustion temperature of the powder of at least 450 ° C. can limit the efficiency in homes that do not reach this temperature.
La présente invention a pour but de remédier à la grande difficulté d'application, en pratique, de cet agent chimique de ramonage. A cet effet, elle a pour objet un nouvel agent chimique de ramonage, qui n'est pas sous forme de poudre. Cet agent, qui est une solution aqueuse d'un composé de métal alcalin et d'un composé de magnésium, est caractérisé en ce que le composé de métal alcalin est l'acétate de potassium, CH3Co2K, en ce que le composé de magnésium est le nitrate de magnésium, (N03)2 Mg, ou un mélange de nitrate de magnésium et d'acétate de magnésium, (CH3C02)2 Mg, et en ce que les proportions relatives du potassium et du magnésium dans l'agent sont de 40 à 60 atomes du premier pour 60 à 40 atomes du second. A titre d'exemple, ladite solution peut renfermer 56 atomes de potassium pour 44 atomes de magnésium. La proportion d'eau est variable, la dilution la plus convenable pouvant être déterminée facilement expérimentalement dans chaque cas particulier d'emploi. La solution initialement préparée et livrée aux utilisateurs est une solution saturée, pour réduire l'encombrement pendant le stockage et le transport.The object of the present invention is to remedy the great difficulty of applying, in practice, this chemical agent chimney sweep. To this end, it relates to a new chemical chimney sweeping agent, which is not in powder form. This agent, which is an aqueous solution of an alkali metal compound and a magnesium compound, is characterized in that the alkali metal compound is potassium acetate, CH 3 Co 2 K, in that the compound of magnesium is magnesium nitrate, (N0 3 ) 2 Mg, or a mixture of magnesium nitrate and magnesium acetate, (CH 3 C0 2 ) 2 M g , and in that the relative proportions of potassium and magnesium in the agent are 40 to 60 atoms of the first for 60 to 40 atoms of the second. For example, said solution can contain 56 potassium atoms for 44 magnesium atoms. The proportion of water is variable, the most suitable dilution being able to be easily determined experimentally in each particular case of use. The solution initially prepared and delivered to users is a saturated solution, to reduce congestion during storage and transport.
Il est possible de remplacer l'acétate de potassium par un équivalent chimique sous forme d'un sel soluble dans l'eau d'un métal alcalino-terreux à la place du potassium et/ou d'un acide organique autre que l'acide acétique, mais, comme ce dernier, usuel et peu coùteux, tel que l'acide formique ou l'acide butyrique.It is possible to replace potassium acetate with a chemical equivalent in the form of a water-soluble salt of an alkaline earth metal in place of potassium and / or an organic acid other than acid acetic, but, like the latter, usual and inexpensive, such as formic acid or butyric acid.
On peut éventuellement ajouter à l'agent liquide considéré des silicates alcalins et/ou alcalino-terreux, par exemple sous forme d'une solution aqueuse saturée ajoutée à la solution aqueuse saturée de l'agent. En effet, dans certains cas, on rencontre non seulement le problème des suies, mais aussi le probléme de la fusion des cendres du combustible. Ce point de fusion est parfois tel que les dépôts de cendres se présentent sous la forme de masses pâteuses. L'addition de silicates permet d'élever le point de fusion de ces cendres, par conséquent, de les rendre "sèches", non adhérentes et par suite facilement éliminables, et moins corrosives, lorsqu'elles renferment des substances corrosives telles que le vanadium, ce qui peut être le cas lorsqu'elles résultent de la combustion du mazout.Optionally, alkali and / or alkaline earth silicates can be added to the liquid agent in question, for example in the form of a saturated aqueous solution added to the saturated aqueous solution of the agent. Indeed, in certain cases, one meets not only the problem of soot, but also the problem of the fusion of the ashes of the fuel. This melting point is sometimes such that the ash deposits are in the form of pasty masses. The addition of silicates makes it possible to raise the melting point of these ashes, consequently, to make them "dry", non-adherent and therefore easily removable, and less corrosive, when they contain corrosive substances such as vanadium. , which may be the case when they result from the combustion of fuel oil.
La proportion des silicates peut être de 5 à 10 % en poids par rapport au poids de l'agent.The proportion of silicates can be from 5 to 10% by weight relative to the weight of the agent.
L'agent liquide de ramonage chimique suivant l'invention est facile à pulvériser dans la flamme du brûleur d'un four ou d'une chaudière au moyen d'air comprimé, ou mieux encore au moyen d'un vibreur électrique. Il ne se produit aucune réaction exothermique susceptible de provoquer une explosion. L'eau s'évapore dès que la solution atteint 100°C, température qu'il est inutile de dépasser. L'extrait sec s'enflamme alors très rapidement, il est décomposé en ses éléments, et les ions libres potassium et magnésium engendrent, dans l'atmosphère oxydante de la flamme renforcée par les ions nitrate oxydants, d'une part, de l'oxyde de potassium (R20), qui se transforme en carbonate de potassium (CO3K2) pulvérulent, en présence du gaz carbonique des gaz de combustion auquel s'ajoute celui provenant de l'oxydation subséquente des suies par ce carbonate, et, d'autre part, de l'oxyde de magnésium (MgO) également à l'état pulvérulent. Le carbonate de potassium assure la combustion catalytique des suies présentes dans les gaz de combustion et sur les surfaces, de la manière susindiquée, par abaissement du point d'ignition du carbone et par un effet d'oxydation du carbone. D'autre part, le carbonate de potassium pulvérulent, qui s'ajoute aux dépôts, n'adhère pas aux parois et est facilement éliminable. Quant à l'oxyde de magnésium, il neutralise les produits d'oxydation du soufre retenus par les dépôts ainsi que l'acide sulfurique condensé dans les zones froides du four ou de la chaudière, alors qu'avec les agents de xamonage chimiques antérieurs, il était généralement nécessaire d'effectuer un traitement complémentaire, consistant à pulvériser dans ces zones froides de l'oxyde de magnésium très fin, en particulier d'une taille inférieure à 10 microns, ce qui n'était pas une opération facile ; avec le nouvel agent de ramonage chimique, MgO est formé in situ. Le carbonate de potassium étant basique, il coopère avec MgO pour l'action de neutralisation. Le sulfate de magnésium et le sulfate de potassium formés sont des produits pulvérulents, non adhérents, facilement éliminables.The liquid chemical sweeping agent according to the invention is easy to spray into the flame of the burner of an oven or a boiler by means of compressed air, or better still by means of an electric vibrator. There is no exothermic reaction which may cause an explosion. The water evaporates as soon as the solution reaches 100 ° C, a temperature which it is useless to exceed. The dry extract then ignites very quickly, it is broken down into its elements, and the free potassium and magnesium ions generate, in the oxidizing atmosphere of the flame reinforced by the oxidizing nitrate ions, on the one hand, potassium oxide (R20), which transforms into powdered potassium carbonate (CO 3 K 2 ), in the presence of the carbon dioxide of the combustion gases, to which is added that resulting from the subsequent oxidation of the soot by this carbonate, and, on the other hand, magnesium oxide (MgO) also in the pulverulent state. The potassium carbonate ensures the catalytic combustion of the soot present in the combustion gases and on the surfaces, in the manner indicated above, by lowering the ignition point of carbon and by an effect of carbon oxidation. On the other hand, the powdery potassium carbonate, which is added to the deposits, does not adhere to the walls and is easily removable. As for magnesium oxide, it neutralizes the sulfur oxidation products retained by the deposits as well as the sulfuric acid condensed in the cold areas of the furnace or the boiler, whereas with the previous chemical xamonage agents, it was generally necessary to carry out a complementary treatment, consisting in spraying in these cold areas very fine magnesium oxide, in particular of a size less than 10 microns, which was not an easy operation; with the new chemical sweeping agent, MgO is formed in situ. Since potassium carbonate is basic, it cooperates with MgO for the neutralizing action. The magnesium sulphate and potassium sulphate formed are powdery, non-adherent, easily removable products.
L'intérêt de l'association de l'acétate de-potassium et du nitrate dé magnésium pour l'élimination des suies et la neutralisation de l'acidité corrosive dans le foyer et dans les conduits de fumée est donc évident.The advantage of the association of potassium acetate and magnesium nitrate for the elimination of soot and the neutralization of corrosive acidity in the hearth and in the flues is therefore obvious.
Ce nouvel agent est ainsi applicable sans danger ni difficultés particulières et il est d'une grande efficacité. De plus, les constituants choisis sont très solubles dans l'eau, ce qui permet de préparer une solution concentrée, dont le faible volume est avantageux pour le stockage et le transport.This new agent is thus applicable without danger or particular difficulties and it is very effective. In addition, the constituents chosen are very soluble in water, which makes it possible to prepare a concentrated solution, the small volume of which is advantageous for storage and transport.
On a aussi constaté, suivant la présente invention, qu'il est particulièrement avantageux que le rapport entre le nombre d'atomes de potassium et le nombre d'ions nitrate (NO3 -) dans le présent agent soit de 1,87, ce qui correspond à 56 atomes de potassium pour 30 ions nitrate.It has also been found, according to the present invention, that it is particularly advantageous that the ratio between the number of potassium atoms and the number of nitrate ions (NO 3 - ) in the present agent is 1.87, this which corresponds to 56 potassium atoms for 30 nitrate ions.
Ce rapport préféré K/NO3 de 1,87 a pour but de rendre optimale la combustion de l'extrait sec obtenu après évaporation de l'eau, lors de l'utilisation dudit agent.The purpose of this preferred K / NO 3 ratio of 1.87 is to optimize the combustion of the dry extract obtained after evaporation of the water, when said agent is used.
Si la teneur en ions N03 est inférieure à 30 ions, la combustion de l'extrait sec est insuffisante pour permettre la décomposition rapide de celui-ci en K20, K2C03, MgO, 02 et N2, d'où une perte d'efficacité de l'agent.If the content of N0 3 ions is less than 30 ions, the combustion of the dry extract is insufficient to allow its rapid decomposition into K 2 0, K 2 C0 3 , MgO, 0 2 and N 2 , d 'where a loss of effectiveness of the agent.
Si la teneur en ions NO3 est supérieure à 30 ions, il y a un risque de formation d'oxydes d'azote toxiques, NOx, ainsi que de produits tels que des nitrites pouvant se retrouver sur les surfaces du four ou de la chaudière et des conduits de fumée, à l'état fondu et inactifs, d'où également une perte d'efficacité de l'agent.If the NO 3 ion content is greater than 30 ions, there is a risk of formation of toxic nitrogen oxides, NO x , as well as products such as nitrites which can be found on the surfaces of the oven or the boiler and flues, in the molten state and inactive, also resulting in a loss of agent efficiency.
Compte tenu du rapport préférentiel K/NO3 de 56 atomes du premier pour 30 ions du second, le magnésium ne peut plus, dans ce cas, être présent dans l'agent uniquement sous forme de nitrate, si l'on veut maintenir le rapport préférentiel K/Mg de 56 atomes du premier pour 44 atomes du second. Le complément de magnésium est alors apporté sous forme d'acétate de magnésium.Taking into account the preferential K / NO 3 ratio of 56 atoms of the first for 30 ions of the second, magnesium can no longer, in this case, be present in the agent only in the form of nitrate, if the ratio is to be maintained preferential K / Mg of 56 atoms of the first for 44 atoms of the second. The magnesium supplement is then provided in the form of magnesium acetate.
Dans ces conditions, l'agent liquide perfectionné suivant la présente invention est caractérisé en ce que le composé de magnésium qu'il renferme est un mélange de nitrate de magnésium, (N03)2 Mg, et d'acétate de magnésium, (CH3C02)2 Mg, dans les proportions préférées de 15 molécules de nitrate pour 29 molécules d'acétate.Under these conditions, the improved liquid agent according to the present invention is characterized in that the magnesium compound which it contains is a mixture of magnesium nitrate, (N0 3 ) 2 Mg, and magnesium acetate, (CH 3 C0 2 ) 2 Mg, in the preferred proportions of 15 molecules of nitrate for 29 molecules of acetate.
L'invention a aussi pour objet le procédé d'application dudit agent consistant à le pulvériser dans la flamme au moyen d'un vibreur électrique, qui permet, beaucoup mieux que l'air comprimé, de contrôler l'injection. On peut alors plus aisément programmer les injections en fonction du temps et les asservir au débit du combustible. Ce dernier peut être indifféremment un combustible solide (charbon, bois, schiste, lignite, par exemple), liquide (mazout)., ou gazeux. La forme liquide, de l'agent et sa pulvérisation assurent une répartition fine optimale et une efficacité maximale de l'agent.The subject of the invention is also the method of applying said agent, consisting in spraying it into the flame by means of an electric vibrator, which makes it much better than air. tablet, control the injection. We can then more easily program the injections as a function of time and control them according to the fuel flow rate. The latter can be either a solid fuel (coal, wood, shale, lignite, for example), liquid (oil), or gas. The liquid form of the agent and its spraying ensure optimum fine distribution and maximum effectiveness of the agent.
On analyse habituellement la teneur en anhydride sulfurique (SO3) des dépôts, lorsqu'on fait du ramonage chimique ; cet anhydride devant être présentement neutralisé par l'oxyde de magnésium, on tient compte des résultats de ladite analyse pour introduire du nitrate de magnésium et éventuellement de l'acétate de magnésium en plus ou moins grandes proportions dans l'agent de ramonage chimique considéré, et le débit d'injection de l'agent ou la fréquence de son injection sont également déterminés par cette analyse ainsi que, bien entendu, par l'importance des dépôts. Alors qu'avec l'agent antérieur à base de nitrate de potassium sous forme de poudre, les injections étaient périodiques, avec le nouvel agent liquide, la pulvérisation dans la flamme peut être effectuée en continu et elle a en continu un effet anti-pollution de l'atmosphère et anti-corrosion de l'appareillage.The sulfur dioxide content (SO 3 ) of the deposits is usually analyzed when chemical sweeping is carried out; this anhydride having to be currently neutralized by magnesium oxide, account is taken of the results of said analysis to introduce magnesium nitrate and optionally magnesium acetate in greater or lesser proportions into the chemical sweeping agent considered, and the agent injection rate or the frequency of its injection are also determined by this analysis as well as, of course, by the extent of the deposits. Whereas with the previous agent based on potassium nitrate in powder form, the injections were periodic, with the new liquid agent, spraying in the flame can be carried out continuously and it has an anti-pollution effect continuously of the atmosphere and anti-corrosion of the equipment.
Un autre objet de l'invention est le procédé de préparation du nouvel agent de ramonage chimique considéré.Another object of the invention is the process for the preparation of the new chemical chimney sweeping agent considered.
Ce procédé consiste à préparer une solution aqueuse saturée d'acétate de potassium et éventuellement d'acétate de magnésium, à partir d'acide acétique et, respectivement, de carbonate de potassium et de carbonate de magnésium, en proportions stoechiométriques, puis à préparer une solution aqueuse saturée de nitrate de magnésium, à partir d'acide nitrique et de carbonate de magnésium en proportions stoechiométriques, toutes ces préparations étant effectuées isolément sous refroidissement, après quoi on mélange les solutions saturées de façon que le rapport du potassium au magnésium dans le mélange soit de 40 à 60 atomes du premier pour 60 à 40 atomes du second et l'on dilue à l'eau d'une façon variable, au moment de l'emploi, le mélange intermédiaire concentré ainsi obtenu, la dilution la plus favorable étant déterminée expérimentalement dans chaque cas d'utilisation de la solution finale.This process consists in preparing a saturated aqueous solution of potassium acetate and optionally magnesium acetate, from acetic acid and, respectively, potassium carbonate and magnesium carbonate, in stoichiometric proportions, then preparing a saturated aqueous solution of magnesium nitrate, starting from nitric acid and magnesium carbonate in stoichiometric proportions, all these preparations being carried out individually under cooling, after which the saturated solutions are mixed so that the ratio of potassium to magnesium in the mixture of 40 to 60 atoms of the first for 60 to 40 atoms of the second and diluted with water in a variable manner, at the time of use, the concentrated intermediate mixture thus obtained, the most favorable dilution being determined experimentally in each case of use of the final solution.
On effectue préférentiellement le mélange de façon qu'il contienne 56 atomes de potassium pour 44 atomes de magnésium et, lorsqu'on veut obtenir le rapport optimal de 1,87 entre le nombre d'atomes de potassium et le nombre d'ions nitrate, de façon qu'il contienne, pour 56 molécules d'acétate de potassium, 15 molécules de nitrate de magnésium et 29 molécules d'acétate de magnésium.The mixing is preferably carried out so that it contains 56 potassium atoms for 44 magnesium atoms and, when we want to obtain the optimal ratio of 1.87 between the number of potassium atoms and the number of nitrate ions, so that it contains, for 56 molecules of potassium acetate, 15 molecules of magnesium nitrate and 29 molecules of magnesium acetate.
On peut éventuellement ajouter des silicates à la solution, comme susindiqué. On a vu précédemment que l'acétate de potassium pouvait être remplacé par un acétate d'un métal alcalino-terreux, auquel cas la matière première carbonate de potassium est remplacée par le carbonate correspondant, et que l'anion acétate pouvait être remplacé par un autre anion, auquel cas on substitue à la matière première acide acétique un autre acide organique facile à se procurer et bon marché.Optionally, silicates can be added to the solution, as indicated above. We have previously seen that potassium acetate could be replaced by an acetate of an alkaline earth metal, in which case the raw material potassium carbonate is replaced by the corresponding carbonate, and that the acetate anion could be replaced by a another anion, in which case the raw material acetic acid is replaced by another organic acid which is easy to obtain and inexpensive.
Pour préparer les acétates de potassium et de magnésium et le nitrate de magnésium, on peut aussi employer la potasse, KOH, et la magnésie, MgO, à la place, respectivement,du carbonate de potassium et du carbonate de magnésium. On emploie également des proportions stoechiométriques de ces bases et des acides acétique et nitrique.To prepare potassium magnesium acetates and magnesium nitrate, potassium hydroxide, KOH, and magnesia, MgO, can also be used instead of potassium carbonate and magnesium carbonate, respectively. Stoichiometric proportions of these bases and of acetic and nitric acids are also used.
En variante, on peut préparer l'agent suivant l'invention de la façon suivante : sous refroidissement, on verse successivement et en proportions stoechiométriques, dans la quantité totale d'eau nécessaire pour obtenir une solution saturée en les quantités voulues des divers constituants, l'acide acétique, le carbonate de potassium ou la potasse nécessaire pour former l'acétate de potassium, le carbonate de magnésium ou la magnésie nécessaire pour former l'acétate de magnésium, l'acide nitrique, le carbonate de magnésium ou la magnésie nécessaire pour former le nitrate de magnésium, puis on dilue à l'eau, au moment de l'emploi, la solution concentrée obtenue, la dilution la plus favorable étant déterminée expérimentalement dans chaque cas d'utilisation de la solution finale.As a variant, the agent according to the invention can be prepared in the following manner: under cooling, successively and in stoichiometric proportions are poured into the total amount of water necessary to obtain a saturated solution in the desired amounts of the various constituents, acetic acid, potassium carbonate or potash necessary to form potassium acetate, magnesium carbonate or magnesia necessary to form magnesium acetate, nitric acid, magnesium carbonate or magnesia necessary to form magnesium nitrate, then dilute with water, at the time of use, the concentrated solution obtained, the most favorable dilution being determined experimentally in each case of use of the final solution.
. Le refroidissement nécessaire au cours de la préparation de l'agent peut être obtenu par une circulation d'eau froide dans le milieu réactionnel (par exemple au moyen d'un serpentin immergé), ou autour de ce milieu ; par exemple, on peut procéder à la préparation dans un récipient chemisé et établir une circulation d'eau de refroidissement dans la chemise du récipient.. The necessary cooling during the preparation of the agent can be obtained by circulating cold water in the reaction medium (for example by means of an immersed coil), or around this medium; for example, the preparation can be carried out in a jacketed container and a circulation of cooling water can be established in the container jacket.
Un exemple préféré de composition de l'agent suivant l'invention est donné ci-après, mais il n'est aucunement limitatifA preferred example of composition of the agent according to the invention is given below, but it is in no way limiting
EXEMPLE :
- Composition de l'agent, sous forme de solution aqueuse saturée (pour 100 parties en poids) :
- Composition of the agent, in the form of a saturated aqueous solution (per 100 parts by weight):
La préparation du produit peut être effectuée selon le procédé indiqué ci-dessus à titre de variante, c'est-à-dire en ajoutant successivement et sous refroidissement, dans les 69,5 parties d'eau, la quantité d'acide acétique nécessaire pour former 14,5 parties d'acétate de potassium et 10,1 parties d'acétate de magnésium, la quantité de carbonate de potassium nécessaire pour former 14,5 parties d'acétate de potassium, la quantité de carbonate de magnésium nécessaire pour former 10,1 parties d'acétate de magnésium, la quantité d'acide nitrique nécessaire pour former 5,9 parties de nitrate de magnésium, et la quantité de carbonate de magnésium nécessaire pour former 5,9 parties de nitrate de magnésium.The preparation of the product can be carried out according to the method indicated above as an alternative, that is to say by successively adding and under cooling, in the 69.5 parts of water, the quantity of acetic acid necessary to form 14.5 parts of potassium acetate and 10.1 parts of magnesium acetate, the amount of potassium carbonate required to form 14.5 parts of potassium acetate, the amount of magnesium carbonate required to form 10.1 parts of magnesium acetate, the amount of nitric acid required to form 5.9 parts of magnesium nitrate, and the amount of magnesium carbonate required to form 5.9 parts of magnesium nitrate.
Cette solution concentrée sera diluée de façon variable au moment de l'emploi et en fonction de l'utilisation.This concentrated solution will be diluted variably at the time of use and depending on the use.
Bien entendu, la carbonate de potassium et le carbonate de magnésium peuvent être remplacés, comme susindiqué, par de la potasse et de la magnésie.Of course, the potassium carbonate and the magnesium carbonate can be replaced, as mentioned above, by potash and magnesia.
Claims (16)
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR7821901A FR2432041A1 (en) | 1978-07-25 | 1978-07-25 | Soln. for destroying soot in chimneys - contg. potassium acetate and magnesium nitrate, and opt. magnesium acetate |
| FR7821901 | 1978-07-25 | ||
| FR7917117A FR2460318A2 (en) | 1979-07-02 | 1979-07-02 | Soln. for destroying soot in chimneys - contg. potassium acetate and magnesium nitrate, and opt. magnesium acetate |
| FR7917117 | 1979-07-02 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0007862A1 true EP0007862A1 (en) | 1980-02-06 |
| EP0007862B1 EP0007862B1 (en) | 1982-01-27 |
Family
ID=26220685
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP79400514A Expired EP0007862B1 (en) | 1978-07-25 | 1979-07-20 | Liquid agent for the chemical destruction of soot and method of application |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0007862B1 (en) |
| DE (1) | DE2961969D1 (en) |
| IT (1) | IT1121017B (en) |
| LU (1) | LU81539A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0042367A3 (en) * | 1980-06-16 | 1982-02-03 | Peter M. Scocca | Method for reduction of sulfur content in exit gases |
| FR2585360A1 (en) * | 1985-07-29 | 1987-01-30 | Rosenbluth Germain | Process for reducing unburnt materials from combustion and agent for its use |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2949008A (en) * | 1958-01-29 | 1960-08-16 | Gulf Research Development Co | Residual fuels |
| FR1326720A (en) * | 1962-05-11 | 1963-05-10 | Maxwell Chemicals Pty Ltd | Method and preparation for the treatment of foci |
| GB1378882A (en) * | 1972-05-16 | 1974-12-27 | Polar Chemicals Ltd | Method for the removal of soot and other deposits formed as a result of the combustion of gaseous liquid and solid fuels |
| FR2235204A1 (en) * | 1973-06-26 | 1975-01-24 | Bergmann Borsig Gorlitzer | Fouling and corrosion inhibition in combustion units - by adding metal salts to fuel |
-
1979
- 1979-07-20 DE DE7979400514T patent/DE2961969D1/en not_active Expired
- 1979-07-20 EP EP79400514A patent/EP0007862B1/en not_active Expired
- 1979-07-23 LU LU81539A patent/LU81539A1/en unknown
- 1979-07-24 IT IT68534/79A patent/IT1121017B/en active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2949008A (en) * | 1958-01-29 | 1960-08-16 | Gulf Research Development Co | Residual fuels |
| FR1326720A (en) * | 1962-05-11 | 1963-05-10 | Maxwell Chemicals Pty Ltd | Method and preparation for the treatment of foci |
| GB1378882A (en) * | 1972-05-16 | 1974-12-27 | Polar Chemicals Ltd | Method for the removal of soot and other deposits formed as a result of the combustion of gaseous liquid and solid fuels |
| FR2235204A1 (en) * | 1973-06-26 | 1975-01-24 | Bergmann Borsig Gorlitzer | Fouling and corrosion inhibition in combustion units - by adding metal salts to fuel |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0042367A3 (en) * | 1980-06-16 | 1982-02-03 | Peter M. Scocca | Method for reduction of sulfur content in exit gases |
| FR2585360A1 (en) * | 1985-07-29 | 1987-01-30 | Rosenbluth Germain | Process for reducing unburnt materials from combustion and agent for its use |
| EP0270719A1 (en) * | 1986-12-12 | 1988-06-15 | TECHNIQUE FRANCAISE DE DETARTRAGE dite T.F.D., Société Anonyme | Process for reducing unburned combustion particles, and agent for carrying out the process |
Also Published As
| Publication number | Publication date |
|---|---|
| IT7968534A0 (en) | 1979-07-24 |
| IT1121017B (en) | 1986-03-26 |
| LU81539A1 (en) | 1980-02-14 |
| DE2961969D1 (en) | 1982-03-11 |
| EP0007862B1 (en) | 1982-01-27 |
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