EP0053085B1 - Method of cleaning surfaces soiled by deposits accrued during conbustion of carbon materials - Google Patents
Method of cleaning surfaces soiled by deposits accrued during conbustion of carbon materials Download PDFInfo
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- EP0053085B1 EP0053085B1 EP81420171A EP81420171A EP0053085B1 EP 0053085 B1 EP0053085 B1 EP 0053085B1 EP 81420171 A EP81420171 A EP 81420171A EP 81420171 A EP81420171 A EP 81420171A EP 0053085 B1 EP0053085 B1 EP 0053085B1
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- Prior art keywords
- injecting
- process according
- deposits
- solution
- installation
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28G—CLEANING OF INTERNAL OR EXTERNAL SURFACES OF HEAT-EXCHANGE OR HEAT-TRANSFER CONDUITS, e.g. WATER TUBES OR BOILERS
- F28G7/00—Cleaning by vibration or pressure waves
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B08—CLEANING
- B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
- B08B7/00—Cleaning by methods not provided for in a single other subclass or a single group in this subclass
- B08B7/0007—Cleaning by methods not provided for in a single other subclass or a single group in this subclass by explosions
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C23G5/00—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents
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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
- F23J3/00—Removing solid residues from passages or chambers beyond the fire, e.g. from flues by soot blowers
- F23J3/02—Cleaning furnace tubes; Cleaning flues or chimneys
- F23J3/023—Cleaning furnace tubes; Cleaning flues or chimneys cleaning the fireside of watertubes in boilers
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28G—CLEANING OF INTERNAL OR EXTERNAL SURFACES OF HEAT-EXCHANGE OR HEAT-TRANSFER CONDUITS, e.g. WATER TUBES OR BOILERS
- F28G9/00—Cleaning by flushing or washing, e.g. with chemical solvents
Definitions
- the present invention relates to a method for cleaning the surfaces of an installation, fouled by deposits, including or not, resulting from the combustion of carbonaceous materials, applicable without having to stop the combustion process.
- any combustion operation using carbonaceous materials is generally accompanied, on the one hand, by the emission of gas. more or less hot, on the other hand, from the formation of non-combustible mineral products and unburned carbon products. These products are more or less entrained in the circuits in which the gases are transported and they can either deposit on their surface or react chemically with the materials constituting said surfaces, due to the high temperature and their composition, melt and adhere to these last. We thus created more or less encrusting deposits.
- Such a method is generally implemented outside any combustion process, that is to say the plant stopped; if not, use blowing heads designed so that they can be exposed to the action of more or less corrosive hot gases without deteriorating.
- Chemical cleaning can also be used, for example, soaking the surfaces to be cleaned with an ammonia solution to neutralize the sulfuric anhydride present in the deposits to be eliminated (see for example FR-A-1 357992).
- this method has the same disadvantages as those mentioned above.
- This process is characterized in that a solution of at least one body capable of chemically reacting with carbonaceous deposits is injected into the installation, in the form of a dispersion which is entrained by the flow of combustion gases. minerals that clog the surfaces, and that the particles resulting from the chemical reactions are moved by phasing with aerial acoustic waves in order to cause them to be entrained by the flow of combustion gases or their fall towards the ashtrays of the installation.
- the cleaning process is characterized, firstly, by injecting into the installation, in the form of a dispersion which is entrained by the flow of combustion gases, a solution of at least one body likely to react chemically with carbon and mineral deposits resulting from the combustion of carbonaceous materials.
- the chemical reaction must most generally lead to the oxidation of the deposits.
- carbon deposits there is combustion, therefore, destruction of said deposits; in the case of mineral deposits, an oxidation reaction takes place leading to an increase in volume, and therefore to the disintegration of the crystal structures of the deposits.
- this destruction of the structures can also be induced by chemical reactions of the decomposition reaction type and / or substitution reactions.
- the chemical reaction must also be able to take place under high temperature chemistry conditions.
- the applicant preferably uses an oxidant and in particular a nitrate, or else a mixture of nitrates such as potassium nitrate and ammonium nitrate, which, when used in aqueous solution, have a concentration of the order of 200 to 300 g / liter.
- the injected body always contains the corrosion inhibitors necessary to avoid chemical attacks on the materials constituting the system. It is also possible to use bodies capable of inducing neutralization and / or substitution reactions. The choice of the constituents of the injected body and the quantities of the injected body also take account of the atmospheric pollution regulations.
- the body is used in the divided state in order to obtain the largest possible contact surface with carbonaceous and mineral deposits, and, consequently, an accelerated chemical reduction.
- This state of division can be further increased by injecting the body in the form of a solution which is atomized by means of ultrasonic atomizers or by any other means capable of ensuring a suitable dispersion and the number and the geographical location of which are essentially a function of the structure of the installation to be cleaned.
- the atomizers can be installed specially for the cleaning operation or permanently on the existing openings of the installation, for example on manholes.
- the body can be injected continuously throughout the cleaning period or in a scheduled fashion.
- the body pulverized and entrained by the gases resulting from the combustion is rapidly brought into contact with the carbonaceous and mineral deposits on which it reacts by causing them combustion or the desired chemical reaction. These reactions cause their fine fragmentation which will promote their subsequent displacement under the action of acoustic waves.
- the system to be cleaned being in normal operation during the injection of the body, the temperatures at which the reactions take place are between 300 and 1000 ° C, and these reactions are therefore very fast, and even require high temperature chemistry.
- the second characteristic of the invention therefore consists in displacing the particles resulting from the chemical reactions in order to cause them to entrain in the flow of combustion gases or their fall towards the ashtrays of the installation.
- This setting in motion of the particles is obtained by their putting in phase with air acoustic waves, generated by sources of sound vibrations. These sources emit vibrations of audible frequencies of 250 Hertz, for example. It is in the audible frequency range that sound sources are most effective for the intended purpose, but it is possible to use infra or ultra-sound sources for certain deposits.
- the deposits which foul the surfaces of the installation are reduced to a more or less pulverulent mass of particles which is either entrained by the gases resulting from the cumbustion and possibly stopped by electrostatic precipitators, or redeposited in certain places of the installation, for example in the lower parts of the installation where it does not hinder the heat exchanges and can be recovered at any time or during a stop of the 'installation according to the design of the latter.
- FIG. 1 shows, schematically, a vertical section of a large power boiler (1) equipped with a burner (2) emitting a flame (3) generating hot gases which circulate in the direction of the arrows (4), accompanied by carbonaceous products and minerals which deposit on the surfaces (5) of the four exchangers (6).
- Four sprayers (7) arranged in different places of the boiler inject the body capable of reacting chemically with the deposits which foul the surfaces while five sound sources (8) have been placed on each of the two lateral sides of the installation, parallel to the axis of the burner.
- FIG. 2 represents a vertical section of a small power steel boiler (9) for the production of hot water or steam equipped with a burner (10) emitting a flame (11) from which result the gases which circulate following the direction of the arrows (12), leaving a part of the solid products which accompany them on the exchange surfaces (13).
- a burner 10
- three injectors (14) were placed while a sound source (15) was placed between the two tubular bundles of the installation.
- FIG. 3 represents a vertical section of a refinery furnace (16) consuming 70 tonnes of heavy fuel oil per day.
- This oven is equipped with three burners (17) which emit flames (18) in each of the three radiation cells (19).
- the combustion gases circulate in the direction of the arrows (20) and allow some of the suspended particles to deposit, which they entrain on the surfaces of the exchangers (21).
- Three sprayers (22) were placed near each of the burners, and a fourth, at the exit of the radiation cells, while seven sound sources (23) were placed for three of them on one of the side walls of the installation at the level of the cells and, for the other four, at the level of the exchangers (21).
- the process was as follows: 200 liters of a solution containing 155 g / l of ammonium nitrate and 135 g / l of potassium nitrate were injected, brought by addition of ammonia at a pH in the region of 9.3 and this, for a period of 60 minutes in four periods of 15 minutes, with a stop of 30 m between each injection.
- the boiler draft was reduced to a minimum in order to avoid loss of body through the chimney and four sound sources installed on the walls of the boiler were activated for 10 seconds every 15 minutes at a frequency of 250 Hz and an intensity of 140 decibels. These sources were kept in service for 24 hours after the end of the injection to complete the cleaning.
- the particles which detached from the surfaces were entrained by the flow of combustion gases and stopped by an electro-filter.
- 5000 liters of a solution containing 115 g / l of ammonium nitrate and 135 g / l of potassium nitrate brought to the surface were injected in five 30-minute periods, separated by 30-minute rest periods. a pH of 9.3 by addition of ammonia.
- This process finds its application in the cleaning of the surfaces of installations such as, in particular, boiler combustion chambers, rotary or static heat exchangers, flues and smoke ducts, electrostatic filters, and on which we want to intervene without having to stop the combustion process and maintain maximum heat output in order to achieve significant energy savings.
Abstract
Description
La présente invention est relative à un procédé de nettoyage des surfaces d'une installation, encrassées par des dépôts inscrutants ou non, résultant de la combustion de matières carbonées, applicable sans avoir à arrêter le processus de combustion.The present invention relates to a method for cleaning the surfaces of an installation, fouled by deposits, including or not, resulting from the combustion of carbonaceous materials, applicable without having to stop the combustion process.
L'homme de l'art sait que toute opération de combustion mettant en oeuvre des matières carbonées, qu'elles soient à l'état gazeux, liquide ou solide, s'accompagne généralement, d'une part, de l'émission de gaz plus ou moins chauds, d'autre part, de la formation de produits minéraux non combustibles et de produits carbonés imbrulés. Ces produits sont plus ou moins entraînés dans les circuits où sont véhiculés les gaz et ils peuvent soit se déposer à leur surface, soit réagir chimiquement avec les matériaux constitutifs desdites surfaces, en raison de la température élevée et de leur composition, fondre et adhérer à ces dernières. On a ainsi création de dépôts plus ou moins incrustants.Those skilled in the art know that any combustion operation using carbonaceous materials, whether in the gaseous, liquid or solid state, is generally accompanied, on the one hand, by the emission of gas. more or less hot, on the other hand, from the formation of non-combustible mineral products and unburned carbon products. These products are more or less entrained in the circuits in which the gases are transported and they can either deposit on their surface or react chemically with the materials constituting said surfaces, due to the high temperature and their composition, melt and adhere to these last. We thus created more or less encrusting deposits.
Ces dépôts encrassent les surfaces avec lesquelles ils sont en contact et ceci peut avoir des conséquences fâcheuses lorsque ces surfaces sont, comme dans le cas de générateurs de chaleur, celles d'échangeurs chargées de transmettre un flux thermique à un fluide circulant de l'autre côté des surfaces. En effet, ces dépôts diminuent le coefficient de transfert de la surface et conduisent à une réduction de rendement calorifique des installations nécessitant parfois leur arrêt.These deposits foul the surfaces with which they are in contact and this can have unfortunate consequences when these surfaces are, as in the case of heat generators, those of exchangers responsible for transmitting a heat flux to a fluid flowing from the other side of surfaces. In fact, these deposits reduce the transfer coefficient of the surface and lead to a reduction in the heat output of the installations sometimes requiring their shutdown.
Il s'avère donc nécessaire de procéder périodiquement au nettoyage de ces surfaces encrassées, afin de supprimer ces dépôts, ou tout au moins, d'en limiter la quantité à une valeur acceptable.It therefore appears necessary to periodically clean these dirty surfaces, in order to remove these deposits, or at least to limit the amount thereof to an acceptable value.
Il est de pratique courante d'effectuer ce nettoyage par insufflation sur la surface à nettoyer d'un fluide sous pression tel que vapeur, eau ou air, qui agit à la fois ou séparément comme agent de refroidissement provoquant une rétraction des dépôts et comme agent mécanique assurant leur désagrégation. ilIt is common practice to perform this cleaning by insufflation on the surface to be cleaned of a pressurized fluid such as vapor, water or air, which acts both or separately as a cooling agent causing a retraction of the deposits and as an agent. mechanical ensuring their disintegration. he
Mais ce procédé requiert l'utilisation de circuits de fluide sous une pression de plusieurs dizaines de bars, et s'applique aux seules surfaces qui peuvent être atteintes directement par le jet de fluide, écartant de ce fait son application aux installations présentant des circuits à chicanes.However, this process requires the use of circuits of fluid under a pressure of several tens of bars, and applies only to the surfaces which can be reached directly by the jet of fluid, thereby ruling out its application to installations having circuits with baffles.
Par ailleurs, un tel procédé est en général mis en oeuvre en dehors de tout processus de combustion, c'est-à-dire l'installation arrêtée; dans le cas contraire, il faut recourir à des têtes de soufflage conçues de façon à pouvoir être exposées à l'action de gaz chauds plus ou moins corrosifs sans se détériorer.Furthermore, such a method is generally implemented outside any combustion process, that is to say the plant stopped; if not, use blowing heads designed so that they can be exposed to the action of more or less corrosive hot gases without deteriorating.
Un autre procédé classique, et sans doute d'une certaine efficacité, consiste à laver les surfaces encrassées, mais on se heurte alors au problème des dépôts qui se dissolvent mal ou qui donnent naissance à des solutions acides conduisant à la corrosion et à la destruction des matériaux constitutifs de l'installation. L'inconvénient réside également dans le fait qu'il faut inévitablement arrêter l'installation à nettoyer pendant un intervalle de temps assez prolongé, ce qui cause d'importantes pertes de productivité dans le cas où celle-ci fait partie d'une unité de fabrication travaillant en continu.Another conventional process, and no doubt of a certain efficiency, consists in washing dirty surfaces, but one then comes up against the problem of deposits which dissolve badly or which give rise to acid solutions leading to corrosion and destruction. of the constituent materials of the installation. The disadvantage also resides in the fact that it is inevitably necessary to stop the installation to be cleaned for a fairly long period of time, which causes significant losses in productivity if it is part of a unit of manufacturing working continuously.
L'homme de l'art sait également qu'il peut résoudre ce problème de nettoyage par un grenaillage des surfaces de l'installation. Toutefois, une telle solution ne trouve son application que dans des installations de constitution particulière et disposées de façon convenable. D'où l'intérêt très limité de ce type de procédé.Those skilled in the art also know that they can solve this cleaning problem by blasting the surfaces of the installation. However, such a solution finds its application only in installations of particular constitution and arranged in a suitable manner. Hence the very limited interest in this type of process.
On peut également faire appel au nettoyage chimique consistant, par exemple, à imbiber les surfaces à nettoyer d'une solution d'ammoniaque pour neutraliser l'anhydride sulfurique présent dans les dépôts à éliminer (voir par exemple FR-A- 1 357992). Cette méthode entraîne toutefois les mêmes inconvénients que ceux cités plus haut.Chemical cleaning can also be used, for example, soaking the surfaces to be cleaned with an ammonia solution to neutralize the sulfuric anhydride present in the deposits to be eliminated (see for example FR-A-1 357992). However, this method has the same disadvantages as those mentioned above.
C'est pourquoi la demanderesse, soucieuse d'apporter sa contribution à un problème d'autant plus important que les économies d'énergie, et, donc, la recherche du rendement maximum des échangeurs de chaleur, constituent aujourd'hui pour les industriels un objectif primordial, a cherché et mis au point un procédé de nettoyage et d'entretien en état de propreté des surfaces encrassées par les dépôts résultant de la combustion de matières carbonées, tel, qu'il soit applicable sans avoir à arrêter en général le processus de combustion dans l'installation, c'est-à-dire sans perturber la marche des unités de production qui sont sous sa dépendance. Ce procédé présente également les avantages suivants: il permet de nettoyer les dépôts les plus adhérents sur des surfaces d'accès difficile sans recourir à l'utilisation de solutions de lavage créatrices de phénomènes de corrosion ou de dispositifs consommant des quantités d'énergie rédhibitoires et sans modification ou adaptation particulière de l'installation à nettoyer.This is why the plaintiff, anxious to make its contribution to a problem all the more important since the energy savings, and, therefore, the search for the maximum output of the heat exchangers, constitute today for the industrialists a primary objective, sought and developed a cleaning and maintenance process in a clean state of surfaces fouled by deposits resulting from the combustion of carbonaceous materials, such that it can be applied without having to stop the process in general of combustion in the installation, that is to say without disturbing the operation of the production units which are under its dependence. This process also has the following advantages: it makes it possible to clean the most adherent deposits on surfaces of difficult access without resorting to the use of washing solutions which create corrosion phenomena or of devices consuming unacceptable amounts of energy and without any particular modification or adaptation of the installation to be cleaned.
Ce procédé est caractérisé en ce que l'on injecte dans l'installation, sous forme d'une dispersion qui est entraînée par le flux des gaz de combustion, une solution d'au moins un corps susceptible de réagir chimiquement avec les dépôts carbonés et minéraux qui encrassent les surfaces, et que l'on déplace les particules résultant des réactions chimiques par mise en phase avec des ondes acoustiques aériennes afin de provoquer leur entraînement par le flux des gaz de combustion ou leur chute vers les cendriers de l'installation.This process is characterized in that a solution of at least one body capable of chemically reacting with carbonaceous deposits is injected into the installation, in the form of a dispersion which is entrained by the flow of combustion gases. minerals that clog the surfaces, and that the particles resulting from the chemical reactions are moved by phasing with aerial acoustic waves in order to cause them to be entrained by the flow of combustion gases or their fall towards the ashtrays of the installation.
Ainsi, le procédé de nettoyage est caractérisé, d'abord, en ce que l'on injecte dans l'installation, sous forme d'une dispersion qui est entraînée par le flux des gaz de combustion, une solution d'au moins un corps susceptible de réagir chimiquement avec les dépôts carbonés et minéraux résultant de la combustion des matières carbonées.Thus, the cleaning process is characterized, firstly, by injecting into the installation, in the form of a dispersion which is entrained by the flow of combustion gases, a solution of at least one body likely to react chemically with carbon and mineral deposits resulting from the combustion of carbonaceous materials.
La réaction chimique doit conduire, le plus généralement, à l'oxydation des dépôts. Dans le cas des dépôts carbonés, il y a combustion, donc, destruction desdits dépôts; dans le cas des dépôts minéraux, il se produit une réaction d'oxydation conduisant à une augmentation de volume, et, donc à la désagrégation des structures cristallines des dépôts. Mais, cette destruction des structures peut également être induite par des réactions chimiques du type réactions de décomposition et/ou des réactions de substitution. La réaction chimique doit aussi pouvoir se produire dans des conditions de chimie des hautes températures.The chemical reaction must most generally lead to the oxidation of the deposits. In the case of carbon deposits, there is combustion, therefore, destruction of said deposits; in the case of mineral deposits, an oxidation reaction takes place leading to an increase in volume, and therefore to the disintegration of the crystal structures of the deposits. However, this destruction of the structures can also be induced by chemical reactions of the decomposition reaction type and / or substitution reactions. The chemical reaction must also be able to take place under high temperature chemistry conditions.
Du point de vue nature du corps injecté, la demanderesse utilise, de préférence, un oxydant et notamment un nitrate, ou encore un mélange de nitrates tels que le nitrate de potassium et le nitrate d'ammonium, lesquels, lorsqu'ils sont utilisés en solution aqueuse, ont une concentration de l'ordre de 200 à 300 g/litre.From the point of view of the nature of the injected body, the applicant preferably uses an oxidant and in particular a nitrate, or else a mixture of nitrates such as potassium nitrate and ammonium nitrate, which, when used in aqueous solution, have a concentration of the order of 200 to 300 g / liter.
Dans certains cas, il est préférable, pour empêcher toute corrosion, d'amener ces solutions à un pH supérieur à 9 en y ajoutant de l'ammoniaque ou tout autre corps susceptible de stabiliser le pH des dépôts.In some cases, it is preferable, to prevent corrosion, to bring these solutions to a pH greater than 9 by adding ammonia or any other body capable of stabilizing the pH of the deposits.
Par ailleurs, le corps injecté contient toujours les inhibiteurs de corrosion nécessaires pour éviter les attaques chimiques sur les matériaux constitutifs du système. On peut, également, utiliser des corps susceptibles d'induire les réactions de neutralisation et/ou de substitution. Le choix des constituants du corps injecté et des quantités du corps injecté tiennent également compte des réglementations en matière de pollution atmosphérique.In addition, the injected body always contains the corrosion inhibitors necessary to avoid chemical attacks on the materials constituting the system. It is also possible to use bodies capable of inducing neutralization and / or substitution reactions. The choice of the constituents of the injected body and the quantities of the injected body also take account of the atmospheric pollution regulations.
De préférence, on met en oeuvre le corps à l'état divisé afin d'obtenir la surface de contact la plus grande possible avec les dépôts carbonés et minéraux, et, par suite, une réduction chimique accélérée.Preferably, the body is used in the divided state in order to obtain the largest possible contact surface with carbonaceous and mineral deposits, and, consequently, an accelerated chemical reduction.
Cet état de division peut être encore augmenté en injectant le corps sous forme d'une solution qui est atomisée au moyen d'atomiseurs ultrasoniques ou de tout autre moyen susceptible d'assurer une dispersion convenable et dont le nombre et la situation géographique sont essentiellement fonction de la structure de l'installation à nettoyer. Mais, ils sont généralement placés de façon que le nuage de corpuscules qu'ils produisent n'entre pas en contact avec la flamme résultant de la combustion des matières carbonées. Les atomiseurs peuvent être installés spécialement pour l'opération de nettoyage ou de façon permanente sur les ouvertures existantes de l'installation, par exemple sur les regards.This state of division can be further increased by injecting the body in the form of a solution which is atomized by means of ultrasonic atomizers or by any other means capable of ensuring a suitable dispersion and the number and the geographical location of which are essentially a function of the structure of the installation to be cleaned. However, they are generally placed so that the cloud of corpuscles they produce does not come into contact with the flame resulting from the combustion of carbonaceous materials. The atomizers can be installed specially for the cleaning operation or permanently on the existing openings of the installation, for example on manholes.
Le corps peut être injecté en continu pendant toute la période de nettoyage ou de façon programmée. Ainsi, sous l'action de cette injection au sein de la zone chaude de l'installation, le corps pulvérisé et entraîné par les gaz résultant de la combustion est rapidement mis en contact avec les dépôts carbonés et minéraux sur lesquels il réagit en provoquant leur combustion ou la réaction chimique désirée. Ces réactions entraînent leur fine fragmentation qui favorisera leur déplacement ultérieur sous l'action des ondes acoustiques.The body can be injected continuously throughout the cleaning period or in a scheduled fashion. Thus, under the action of this injection within the hot zone of the installation, the body pulverized and entrained by the gases resulting from the combustion is rapidly brought into contact with the carbonaceous and mineral deposits on which it reacts by causing them combustion or the desired chemical reaction. These reactions cause their fine fragmentation which will promote their subsequent displacement under the action of acoustic waves.
Le système à nettoyer étant en marche normale pendant l'injection du corps, les températures auxquelles se produisent les réactions sont comprise entre 300 et 1000°C, et ces réactions sont donc très rapides, et même font appel à la chimie des hautes températures.The system to be cleaned being in normal operation during the injection of the body, the temperatures at which the reactions take place are between 300 and 1000 ° C, and these reactions are therefore very fast, and even require high temperature chemistry.
La deuxième caractéristique de l'invention consiste donc à déplacer les particules résultant des réactions chimiques afin de provoquer leur entraînement dans le flux des gaz de combustion ou leur chute vers les cendriers de l'installation. Cette mise en mouvement des particules est obtenue par leur mise en phase avec des ondes acoustiques aériennes, générées par des sources de vibrations sonores. Ces sources émettent des vibrations de fréquences audibles de 250 Hertz, par exemple. C'est dans le domaine de fréquences audibles que les sources sonores sont les plus efficaces pour le but recherché, mais il est possible de recourir à de sources infra ou ultra-sonores pour certains dépôts.The second characteristic of the invention therefore consists in displacing the particles resulting from the chemical reactions in order to cause them to entrain in the flow of combustion gases or their fall towards the ashtrays of the installation. This setting in motion of the particles is obtained by their putting in phase with air acoustic waves, generated by sources of sound vibrations. These sources emit vibrations of audible frequencies of 250 Hertz, for example. It is in the audible frequency range that sound sources are most effective for the intended purpose, but it is possible to use infra or ultra-sound sources for certain deposits.
Du point de vue puissance, une gamme comprise entre 100 et 200 décibels par source doit être mise en oeuvre.From the power point of view, a range between 100 and 200 decibels per source must be implemented.
Ces sources doivent être à des emplacements judicieusement choisis en fonction des caractéristiques de l'installation, de la nature, de la situation géographique et de la quantité des dépôts à éliminer. Elles sont plus ou moins éloignées les unes des autres en fonction de leur rayon d'action. Leur conception doit être telle qu'elles puissent supporter des températures allant jusqu'à 1000°C sans se détériorer. Elles sont placées sur l'installation au moment du nettoyage ou restent à demeure.These sources must be in places judiciously chosen according to the characteristics of the installation, the nature, the geographical situation and the quantity of deposits to be eliminated. They are more or less distant from each other according to their radius of action. Their design must be such that they can withstand temperatures up to 1000 ° C without deteriorating. They are placed on the installation at the time of cleaning or remain permanently.
Ainsi, sous l'action combinée du corps injecté et des ondes acoustiques, les dépôts qui encrassent les surfaces de l'installation, se trouvent réduits à une masse plus ou moins pulvérulente de particules qui est, soit entraînée par les gaz résultant de la cumbustion et arrêtée éventuellement par des électrofiltres, soit redéposée en certains endroits de l'installation, par exemple dans les parties basses de l'installation où elle ne gêne pas les échanges thermiques et pourra être récupérée à tout moment ou lors d'un arrêt de l'installation suivant la conception de cette dernière.Thus, under the combined action of the injected body and the acoustic waves, the deposits which foul the surfaces of the installation, are reduced to a more or less pulverulent mass of particles which is either entrained by the gases resulting from the cumbustion and possibly stopped by electrostatic precipitators, or redeposited in certain places of the installation, for example in the lower parts of the installation where it does not hinder the heat exchanges and can be recovered at any time or during a stop of the 'installation according to the design of the latter.
La présente invention est illustrée par les dessins qui accompagnent la demande. Ces dessins représentent différents types d'installations susceptibles de recevoir application du procédé revendiqué.
- La figure 1 concerne une chaudière de grande puissance.
- La figure 2 concerne une chaudière de petite puissance.
- La figure 3 concerne un four de raffinerie.
- Figure 1 relates to a large power boiler.
- Figure 2 relates to a small power boiler.
- Figure 3 relates to a refinery furnace.
La figure 1 représente, de façon schématique, une coupe verticale d'une chaudière de grande puissance (1) équipée d'un brûleur (2) émettant une flamme (3) générant des gaz chauds qui circulent suivant le sens des flèches (4), accompagnés par des produits carbonés et des produits minéraux qui viennent se déposer sur les surfaces (5) des quatre échangeurs (6). Quatre pulvérisateurs (7) disposés en différents endroits de la chaudière injectent le corps susceptible de réagir chimiquement avec les dépôts qui encrassent les surfces tandis que cinq sources sonores (8) ont été placées sur chacune des deux faces latérales de l'installation, parallèles à l'axe du brûleur.Figure 1 shows, schematically, a vertical section of a large power boiler (1) equipped with a burner (2) emitting a flame (3) generating hot gases which circulate in the direction of the arrows (4), accompanied by carbonaceous products and minerals which deposit on the surfaces (5) of the four exchangers (6). Four sprayers (7) arranged in different places of the boiler inject the body capable of reacting chemically with the deposits which foul the surfaces while five sound sources (8) have been placed on each of the two lateral sides of the installation, parallel to the axis of the burner.
La figure 2 représente une coupe verticale d'une chaudière acier de petite puissance (9) pour la production d'eau chaude ou de vapeur équipée d'un brûleur (10) émettant une flamme (11) d'où résultent des gaz qui circulent suivant le sens des flèches (12) en abandonnant une partie des produits solides qui les accompagnent sur les surfaces d'échange (13). Pour appliquer le procédé, on a placé trois injecteurs (14) tandis qu'une source sonore (15) a été mise en place entre les deux faisceaux tubulaires de l'installation.FIG. 2 represents a vertical section of a small power steel boiler (9) for the production of hot water or steam equipped with a burner (10) emitting a flame (11) from which result the gases which circulate following the direction of the arrows (12), leaving a part of the solid products which accompany them on the exchange surfaces (13). To apply the method, three injectors (14) were placed while a sound source (15) was placed between the two tubular bundles of the installation.
La figure 3 représente une coupe verticale d'un four (16) de raffinerie consommant 70 tonnes de fuel lourd par jour. Ce four est équipé de trois brûleurs (17) qui émettent des flammes (18) dans chacune des trois cellules de radiation (19). Les gaz de combustion circulent suivant le sens des flèches (20) et laissent déposer une partie des particules en suspension qu'elles entraînent sur les surfaces des échangeurs (21). Trois pulvérisateurs (22) ont été disposés près de chacun des brûleurs, et un quatrième, à la sortie des cellules de radiation, tandis que sept sources sonores (23) ont été placées pour trois d'entre elles sur une des parois latérales de l'installation au niveau des cellules et, pour les quatre autres, au niveau des échangeurs (21).FIG. 3 represents a vertical section of a refinery furnace (16) consuming 70 tonnes of heavy fuel oil per day. This oven is equipped with three burners (17) which emit flames (18) in each of the three radiation cells (19). The combustion gases circulate in the direction of the arrows (20) and allow some of the suspended particles to deposit, which they entrain on the surfaces of the exchangers (21). Three sprayers (22) were placed near each of the burners, and a fourth, at the exit of the radiation cells, while seven sound sources (23) were placed for three of them on one of the side walls of the installation at the level of the cells and, for the other four, at the level of the exchangers (21).
Pour mieux faire comprendre l'invention, on décrit maintenant deux exemples d'application de l'invention.To better understand the invention, two examples of application of the invention are now described.
Une chaudière classique à eau surchauffée, d'une puissance calorifique de 10 thermies par heure, chauffée au charbon, en service permanent, a été traitée pendant la marche suivant le procédé de l'invention pour nettoyer à la fois les zones de radiation et d'échange de chaleur.A conventional superheated water boiler, with a heat output of 10 therms per hour, heated with coal, in permanent service, was treated during operation according to the method of the invention to clean both the radiation and heat exchange.
Le processus a été le suivant: on a injecté 200 litres d'une solution contenant 155 g/I de nitrate d'ammonium et 135 g/I de nitrate de potassium, amenée par addition d'ammoniaque à un pH voisin de 9,3 et ce, pendant une durée de 60 minutes en quatre périodes de 15 minutes, avec un arrêt de 30 m entre chaque injection.The process was as follows: 200 liters of a solution containing 155 g / l of ammonium nitrate and 135 g / l of potassium nitrate were injected, brought by addition of ammonia at a pH in the region of 9.3 and this, for a period of 60 minutes in four periods of 15 minutes, with a stop of 30 m between each injection.
Pendant la durée de l'injection, le tirage de la chaudière a été réduit au minimum afin d'éviter des pertes de corps par la cheminée et quatre sources sonores installées sur les parois de la chaudière ont été mises en action pendant 10 secondes toutes les 15 minutes suivant une fréquence de 250 Hz et une intensité de 140 décibels. Ces sources étaient maintenues en service pendant 24 heures après la fin de l'injection pour parfaire le nettoyage. Les particules qui se sont détachées des surfaces ont été entraînées par le flux des gaz de combustion et arrêtées par un électro- filtre.During the injection period, the boiler draft was reduced to a minimum in order to avoid loss of body through the chimney and four sound sources installed on the walls of the boiler were activated for 10 seconds every 15 minutes at a frequency of 250 Hz and an intensity of 140 decibels. These sources were kept in service for 24 hours after the end of the injection to complete the cleaning. The particles which detached from the surfaces were entrained by the flow of combustion gases and stopped by an electro-filter.
Le rendement thermique de la chaudière qui avait chuté à 85% de la normale était redevenu voisin de 98% après traitement.The thermal efficiency of the boiler which had dropped to 85% of normal had become close to 98% after treatment.
Un four de raffinerie du type représenté sur la figure 3 consommant 300 tonnes de fuel lourd par jour, en service depuis plus de six mois a été traité par le procédé de l'invention pour assurer le nettoyage des cellules de combustion et des échangeurs. Pour cela, on a injecté en cinq périodes de 30 minutes, séparées par des périodes de repos de 30 minutes, 5000 litres d'une solution contenant 115 g/I de nitrate d'ammonium et 135 g/1 de nitrate de potassium amenée à un pH de 9,3 par addition d'ammoniaque.A refinery furnace of the type shown in FIG. 3 consuming 300 tonnes of heavy fuel per day, in service for more than six months, was treated by the process of the invention to ensure the cleaning of the combustion cells and of the exchangers. To do this, 5000 liters of a solution containing 115 g / l of ammonium nitrate and 135 g / l of potassium nitrate brought to the surface were injected in five 30-minute periods, separated by 30-minute rest periods. a pH of 9.3 by addition of ammonia.
A la suite de chaque période d'injection, on mettait en action pendant 15 secondes, sept sources sonores réparties suivant la figure 3. Après entraînement des particules par les fumées ou leur dépôt dans le bas de l'installation, le rendement thermique de l'installation, qui avait chuté à 80%, est repassé à 95% de la normale habituelle.Following each injection period, seven sound sources were distributed for 15 seconds, distributed according to FIG. 3. After entrainment of the particles by the fumes or their deposition at the bottom of the installation, the thermal efficiency of the The installation, which had dropped to 80%, has returned to 95% of normal.
Ce procédé trouve son application dans le nettoyage des surfaces d'installations telles que, notamment, chambres de combustion de chaudières, échangeurs de chaleur tournants ou statiques, conduits et gaines de fumées, filtres électrostatiques, et sur lesquelles on veut intervenir sans avoir à arrêter le processus de combustion et maintenir un rendement calorifique maximum de manière à réaliser d'importantes économies d'énergie.This process finds its application in the cleaning of the surfaces of installations such as, in particular, boiler combustion chambers, rotary or static heat exchangers, flues and smoke ducts, electrostatic filters, and on which we want to intervene without having to stop the combustion process and maintain maximum heat output in order to achieve significant energy savings.
Claims (12)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT81420171T ATE5023T1 (en) | 1980-11-26 | 1981-11-23 | PROCESS FOR CLEANING SURFACES CONTAMINATED BY DEPOSITS FROM COMBUSTION OF CARBON CONTAINING MATERIALS. |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8025389 | 1980-11-26 | ||
| FR8025389A FR2494814A1 (en) | 1980-11-26 | 1980-11-26 | METHOD FOR CLEANING THE SURFACES OF AN INSTALLATION, SECURED BY DEPOSITS RESULTING FROM THE COMBUSTION OF CARBON MATERIALS |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0053085A1 EP0053085A1 (en) | 1982-06-02 |
| EP0053085B1 true EP0053085B1 (en) | 1983-10-12 |
Family
ID=9248489
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP81420171A Expired EP0053085B1 (en) | 1980-11-26 | 1981-11-23 | Method of cleaning surfaces soiled by deposits accrued during conbustion of carbon materials |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US4396434A (en) |
| EP (1) | EP0053085B1 (en) |
| AT (1) | ATE5023T1 (en) |
| CA (1) | CA1173335A (en) |
| DE (1) | DE3161192D1 (en) |
| ES (1) | ES8300996A1 (en) |
| FR (1) | FR2494814A1 (en) |
| GR (1) | GR68327B (en) |
| PT (1) | PT74036B (en) |
Families Citing this family (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2095283B (en) * | 1981-02-09 | 1984-08-01 | Polarchem Ltd | Method for the prevention of deposits on or the removal ofdeposits from heating and ancillary surfaces |
| DE3200582C1 (en) * | 1982-01-12 | 1983-04-07 | Heinrich, Emil, 7054 Korb | Process for removing lubricants from molded parts pressed from metal powder and device for carrying out the process |
| CA1201032A (en) * | 1982-10-28 | 1986-02-25 | 633972 Ontario Limited | Condensing furnaces |
| US4655846A (en) * | 1983-04-19 | 1987-04-07 | Anco Engineers, Inc. | Method of pressure pulse cleaning a tube bundle heat exchanger |
| US4645542A (en) * | 1984-04-26 | 1987-02-24 | Anco Engineers, Inc. | Method of pressure pulse cleaning the interior of heat exchanger tubes located within a pressure vessel such as a tube bundle heat exchanger, boiler, condenser or the like |
| US4773357A (en) * | 1986-08-29 | 1988-09-27 | Anco Engineers, Inc. | Water cannon apparatus and method for cleaning a tube bundle heat exchanger, boiler, condenser, or the like |
| US4960577A (en) * | 1988-02-04 | 1990-10-02 | Acurex Corporation | Enhanced sorbent injection combined with natural gas reburning for a sox control for coal fired boilers |
| JPH04227487A (en) * | 1990-05-18 | 1992-08-17 | Westinghouse Electric Corp <We> | Method of removing sludge and corrosion product |
| US5461123A (en) * | 1994-07-14 | 1995-10-24 | Union Carbide Chemicals & Plastics Technology Corporation | Gas phase fluidized bed polyolefin polymerization process using sound waves |
| ES2124011T3 (en) * | 1994-08-23 | 1999-01-16 | Foster Wheeler Energia Oy | OPERATING PROCEDURE OF A FLUIDIZED BED REACTOR SYSTEM AND ASSOCIATED SYSTEM. |
| US5960086A (en) * | 1995-11-02 | 1999-09-28 | Tri-Strata Security, Inc. | Unified end-to-end security methods and systems for operating on insecure networks |
| FI109098B (en) * | 2000-04-14 | 2002-05-31 | Nirania Ky | Acoustic Cleaning Apparatus and Method |
| WO2003066795A1 (en) * | 2002-02-08 | 2003-08-14 | Sk Corporation | Cleaning agent and method for cleaning heater tubes |
| US7360508B2 (en) * | 2004-06-14 | 2008-04-22 | Diamond Power International, Inc. | Detonation / deflagration sootblower |
| US20070149432A1 (en) * | 2004-08-03 | 2007-06-28 | Jeon-Keun Oh | Cleaning agent and method for cleaning heater tubes |
| KR100686361B1 (en) | 2005-11-28 | 2007-02-26 | 날코코리아 유한회사 | Cleaning composition for fuel apparatus |
| UA95486C2 (en) * | 2006-07-07 | 2011-08-10 | Форс Текнолоджи | Method and system for enhancing application of high intensity acoustic waves |
| US11371788B2 (en) * | 2018-09-10 | 2022-06-28 | General Electric Company | Heat exchangers with a particulate flushing manifold and systems and methods of flushing particulates from a heat exchanger |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US621884A (en) * | 1899-03-28 | John macnaull wilson | ||
| US2351163A (en) * | 1943-01-21 | 1944-06-13 | Diamond Power Speciality | Boiler cleaner |
| US2664274A (en) * | 1951-12-22 | 1953-12-29 | Lummus Co | Method and apparatus employing sonic waves in heat exchange |
| US2935956A (en) * | 1954-09-22 | 1960-05-10 | Jack F Govan | Slag control |
| US3234580A (en) * | 1961-07-19 | 1966-02-15 | Julian W Keck | Treatment of heat exchanger surfaces |
| BE632703A (en) * | 1962-05-24 | 1900-01-01 | ||
| US3457108A (en) * | 1964-08-03 | 1969-07-22 | Dow Chemical Co | Method of removing adherent materials |
| US3544366A (en) * | 1967-02-03 | 1970-12-01 | Carlo W Uhlmann | Method for removing incrustation from metal surfaces |
| FI52147C (en) * | 1971-08-19 | 1977-06-10 | Ahlstroem Oy | Method and apparatus for external cleaning of the boiler piping |
| SE365753B (en) * | 1972-01-04 | 1974-04-01 | Tri Innovations Ab |
-
1980
- 1980-11-26 FR FR8025389A patent/FR2494814A1/en active Pending
-
1981
- 1981-11-12 US US06/320,301 patent/US4396434A/en not_active Expired - Fee Related
- 1981-11-23 DE DE8181420171T patent/DE3161192D1/en not_active Expired
- 1981-11-23 EP EP81420171A patent/EP0053085B1/en not_active Expired
- 1981-11-23 CA CA000390677A patent/CA1173335A/en not_active Expired
- 1981-11-23 AT AT81420171T patent/ATE5023T1/en not_active IP Right Cessation
- 1981-11-24 GR GR66603A patent/GR68327B/el unknown
- 1981-11-25 PT PT74036A patent/PT74036B/en unknown
- 1981-11-25 ES ES507417A patent/ES8300996A1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| PT74036A (en) | 1981-12-01 |
| DE3161192D1 (en) | 1983-11-17 |
| PT74036B (en) | 1983-04-26 |
| US4396434A (en) | 1983-08-02 |
| FR2494814A1 (en) | 1982-05-28 |
| ES507417A0 (en) | 1982-11-01 |
| EP0053085A1 (en) | 1982-06-02 |
| CA1173335A (en) | 1984-08-28 |
| ES8300996A1 (en) | 1982-11-01 |
| ATE5023T1 (en) | 1983-10-15 |
| GR68327B (en) | 1981-11-30 |
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