EP0026707B1 - Process for treating by drying and/or heating combustible granular and/or pulverulent material, and assembly for carrying out the process - Google Patents

Process for treating by drying and/or heating combustible granular and/or pulverulent material, and assembly for carrying out the process Download PDF

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Publication number
EP0026707B1
EP0026707B1 EP80401365A EP80401365A EP0026707B1 EP 0026707 B1 EP0026707 B1 EP 0026707B1 EP 80401365 A EP80401365 A EP 80401365A EP 80401365 A EP80401365 A EP 80401365A EP 0026707 B1 EP0026707 B1 EP 0026707B1
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Prior art keywords
entrainment
fluidisation
agent
gaseous
coal
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Expired
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EP80401365A
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German (de)
French (fr)
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EP0026707A1 (en
Inventor
Roger Marcel Puff
Jean-Claude Kita
Henri Brice
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Charbonnages de France CDF
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Charbonnages de France CDF
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Priority claimed from FR7923920A external-priority patent/FR2465774A1/en
Priority claimed from FR8012876A external-priority patent/FR2484069A1/en
Application filed by Charbonnages de France CDF filed Critical Charbonnages de France CDF
Priority to AT80401365T priority Critical patent/ATE5082T1/en
Publication of EP0026707A1 publication Critical patent/EP0026707A1/en
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    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10B—DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
    • C10B57/00—Other carbonising or coking processes; Features of destructive distillation processes in general
    • C10B57/04—Other carbonising or coking processes; Features of destructive distillation processes in general using charges of special composition
    • C10B57/06—Other carbonising or coking processes; Features of destructive distillation processes in general using charges of special composition containing additives
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10B—DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
    • C10B57/00—Other carbonising or coking processes; Features of destructive distillation processes in general
    • C10B57/08—Non-mechanical pretreatment of the charge, e.g. desulfurization
    • C10B57/10—Drying

Definitions

  • the invention relates to a process and an installation for treatment by drying and / or heating by fluidization and / or gaseous entrainment of a granular and / or pulverulent combustible material, such as a coal to be dried and / or preheated for charging.
  • a granular and / or pulverulent combustible material such as a coal to be dried and / or preheated for charging.
  • coke ovens of low-coking coals by the techniques known as dry charging and preheated charging, or any other application for subsequent physical or chemical treatment.
  • the preheating of coal fines involves the use of oxygen-free fumes, and at a temperature not to exceed approximately 500 to 800 ° C. To achieve this result, it has been proposed to recycle in the combustion chamber, where neutral combustion is carried out, part of the fumes used for preheating.
  • the carbon particles must be finely ground, for example 80% and even 90% less than 2 mm. These fine particles of coal preheated to 250 ° C. are separated from the entrainment fluid by means of two stages of cyclones, the capture efficiency of which is 98 to 99%.
  • the smoke treatment system achieves the result but it does not only have advantages.
  • the un purified recycled fumes therefore still charged with fine dust, are introduced, by means of a fan, into the combustion chamber, at the level of the burner which operates in stoichiometric combustion and therefore at a close temperature the theoretical temperature which, for coke oven gas, exceeds 2000 ° C. Fine particles of carbon can burn, or melt, which is undesirable.
  • the fumes at the outlet of the cyclones must be purified before being released into the atmosphere.
  • a dry dusting is carried out on the exhaust fumes only, while in a second type, as in FR-A-2 207 592, all of the fumes, recycled or not, are subjected to dry dusting.
  • the installation when the installation is in standby conditions (for example in the event of an incident upstream or downstream of the preheater), the quantity of fumes discharged into the atmosphere becomes very small, so that in the case of the first type, the final dust collector, disposed on the venting pipe, arrives at working at zero or very low flow rate.
  • the dust collector is of the wet type, for example high-energy venturi, the reduction in the flow of smoke is not a problem.
  • a wet dust collector is inappropriate because the dust collected is advantageously to be introduced into the coke fines.
  • a dry type dust collector bag filter and electrostatic precipitator
  • the reduction in the smoke flow causes condensation and consequently corrosions in the device.
  • the dust collector risks being in a vacuum system, thus causing parasitic air to enter the installation.
  • the main object of the invention is to avoid the drawbacks of the two aforementioned types of installations comprising dry dust removal and to propose a new process and a new installation having a dry dust collector that is not overloaded or oversized, and not subject to corrosion by risk of insufficient flow causing the temperature to drop below the dew point, especially during waiting periods with low heat production in the installation. In other words, it is desired to obtain the optimum dedusting efficiency from the deduster.
  • Another object of the invention is to propose a solution to the problem of the recovery, handling and re-use of the dust recovered by means of a particular treatment which will be explained.
  • the objects of the invention are achieved by a method of treatment by drying and / or preheating by entrainment and / or fluidization of a granular or pulverulent combustible material, in which the material is dried and / or heated by entrainment and / or fluidization by introducing it into a drive and / or fluidization enclosure, where a drive and / or fluidization regime is established at a given temperature by means of a neutral gaseous agent obtained at temperature and in regulated quantities in a combustion chamber , and from which the dried and / or heated material is extracted by pneumatic transport within the effluent gas agent, then said material is separated from said effluent gas agent by distributing said gaseous agent in regulated quantities between a recycling line to the combustion chamber and a discharge outlet for the surplus, process in which the surplus gaseous agent is dusted by a dry dust collector, thanks to the fact that dust is also removed at s ec in the latter a regulated part of the recycled gaseous agent, at least during
  • the dry dust collector works in all circumstances at a constant gas flow rate and at a suitable temperature, already already regulated by adjusting the burner of the combustion chamber. For each type of dust, there is an optimal efficiency obtained by a corresponding gas passage speed.
  • the second object is achieved by a process in which a liquid hydrocarbon binder is injected into the solid fuel in one of the treatment stages, thanks to the fact that the dust is trapped in a hot carbonaceous liquid. captured by the dry dust collector and said hot carbonaceous liquid charged with said dust is used as an auxiliary hydrocarbon binder, at least partially.
  • said hot carbonated liquid, charged with said dust is injected into the combustible material after the point of separation from the heat transfer gas having served as a gaseous effluent transport agent.
  • the carbonated liquid it is advantageous for the carbonated liquid to be very mobile and very wetting for dust.
  • it will advantageously be chosen from the group consisting of hydrocarbons liquid at room temperature or after reheating, such as heavy fuel oil, petroleum bitumens. In this way we will obtain a pumpable mixture allowing its incorporation into preheated coal, as indicated above.
  • the means for regulating the quantity of gaseous agent passing through the filter to act directly on said first means for distributing the gaseous agent.
  • the object of the invention is also achieved by an installation of the above type com taking a means for introducing liquid hydrocarbon binder into the solid fuel at one of the stages of the treatment and a device for trapping in carbonaceous liquid the dust collected by the dust collector.
  • the means for introducing the liquid hydrocarbon binder into the solid fuel, such as coal open downstream of the point of exit of said fuel from the coal / gas separator device, preferably in a mixing conveyor screw, such as it is known per se.
  • the installation comprises, in addition to this means of introducing the liquid hydrocarbon binder into the fuel, a conventional contiguous means of direct introduction of hydrocarbon binder and / or carbonaceous liquid.
  • a coal preheating installation comprises a preheater dryer-mill designated as a whole by 10. This comprises a vertical pipe 11 for driving the coal up by hot smoke, a screw conveyor 12 bringing the coal from a hopper 13 to the pipe 11 at a point situated above a venturi 14 provided in the lower part of the pipe 11.
  • a fluidization enclosure 15 in the lower part of which opens the said pipe 11, below a rotary impact mill 16.
  • the pipe 17 makes it possible to drive this coal towards a battery of cyclones 18 comprising two stages, primary cyclone and secondary cyclones , at the tip of which this coal is recovered on a screw conveyor 19 to a storage hopper with a view to its subsequent charging in a coke oven.
  • the fumes are recovered in a recycling pipe 21 by means of a fan 22.
  • the installation comprises a combustion chamber 20 opening at the base of the ascending pipe 11.
  • This combustion chamber is supplied by a double burner 30 in all points similar to that which is described in FR-A-2 378 081, it that is to say that it comprises a burner 31, called the main burner, in normal operation for the preheating of the coal, the other 36, called the auxiliary burner, for putting the installation on standby in the event of interruption of the supply of coal by the conveyor 12.
  • Each burner is provided with means for regulating the combustion air so that the combustion is substantially neutral and also comprises means for regulating the fuel subject to temperature measurements in the fluidization enclosure.
  • the fan 22 recycles by ducts 23 a portion of the fumes withdrawn in 21 in a regulated quantity such that the speed of the total gas flow is kept constant in the fluidization enclosure 15.
  • a regulation assembly 48 makes it possible to regulate the combustion with the double burner 30 as a function of the temperature measured at 43 in enclosure 15.
  • a dry electrostatic dust collector 24 is supplied by a line 2, derived from the recycling line 21, from where it separates from part 3 of the line 21.
  • the dust collector 24 supplies a discharge line 5 and another recycling pipe 7 joining the pipe 3 upstream of the recycling fan 22.
  • Valves, namely 9 on the pipe 2, 6 on the discharge pipe 5 and 42 on the pipe 3 in its short-circuiting part the filter 24, make it possible to distribute at will the normal gas flow rate V of the line 21 between a flow rate V 1 of direct recycling in the line 3, a flow rate V 2 of recycling with dedusting through the line 7 which joins the line 3 and a flow rate V 3 of evacuated gaseous effluent.
  • the pressure drop of cyclones 18, a function of the gas flow rate V, is kept constant, as it is known per se, by the action of a valve 1.
  • the flow rate V 3 of gaseous effluent to be discharged is adjusted by the valve 6 which acts as a pressure regulator to keep the pressure in the electrostatic precipitator 24 constant.
  • a greater or lesser part of the flow recycled in the combustion chamber 20 measured at 4 is diverted to be definitively discharged at 5.
  • the vacuum observed between the inlet and the outlet of the dust collector is measured, the measurement is introduced into a regulator 37 which controls the valve 42 and / or the valve 9 so as to ensure compliance with a set value for vacuum between inlet and outlet of the dust collector.
  • the purpose of the separation stage constituted by the cyclones 18, is to separate the granular and / or powdered coal which is dried and / or heated and the entrainment gases by accepting the minimum loss of one and the other.
  • the purpose of the dedusting stage is to restore to the atmosphere or to recycle a gas as free as possible from the dust, for example about ⁇ 0.05 mm, entrained in the vortex of the cyclones.
  • the total smoke flow V ie 66,000 m 3 N / h which circulates in the preheater, is kept constant by adjusting the flow of smoke V1 + V2 recycled into the combustion chamber by means of the fan 22.
  • the excess flow V3 is rejected at the atmosphere.
  • the volume V3 is 24,000 m 3 N / h of smoke. This is by definition the nominal flow rate of the electrostatic precipitator.
  • the dust collected in the dry dust collector is sent into the screw conveyor 19 through a carbonaceous liquid trapping device, simply shown by the rectangle 60 in FIG. 1, but shown schematically in its entirety at Figure 2.
  • an Archimedes screw 62 supplying a homogenization kneading device 63 of sufficient capacity supplied with liquid and hot hydrocarbon product via a pipe 64.
  • the mixture is put into circulation closed in line 64 by means of a pump 67.
  • the pure liquid is topped up by a line 68 in the device 63.
  • a fraction of mixture, corresponding to the production of soot associated with the quantity of liquid sufficient for handling and necessary for the process, is taken from the closed circulation circuit and brought by a pipe 70 to the point of use.
  • the point of use is the aforementioned screw conveyor 19. It is advantageous to provide an additional point of introduction of the carbonaceous liquid at 74 on the mixing screw 19.
  • All the pipes are heated by steam, the pipes can be swept with steam to be purged and it is advantageous to control the proportion of the liquid / soot mixture to the flow of preheated coal, as is known per se adding hydrocarbon binder to preheated coal.
  • the invention makes it possible to recover the soot recovered in a dry dust collector without humidifying with water, to handle the soot safely and without pollution and to transport it to a point of use at a height compatible with the pressure. pump discharge.
  • the invention also makes it possible to recycle the sootings of dry dedusting in the coke paste preheated with fuel.
  • the invention also makes it possible to limit takeoffs during charging and to limit takeoffs during charging with the fuel mixture.
  • a fraction of the fuel at the rate of approximately 400 kg / h is sprayed with steam in the mixer.
  • the rest, about 150 kg / h, is sprayed pure onto the preheated coal in the mixing auger.
  • the invention also makes it possible to recycle the soot in the coke paste preheated with a petroleum bitumen, which, moreover, used alone, would have allowed to bring to the preheated coke paste the cohesion necessary to form either balls, or a bread pounded from dry and hot coal and to prepare either balls or a pounded bread after adding in the mixing screw the quantity total of necessary binder of which all or part will have been used to handle the soot.
  • soot is produced using an electrostatic precipitator.
  • a total of 6% by weight of a petroleum bitumen heated to 150 ° C. is added (percentage based on the total quantity of preheated coal).
  • a fraction of the bitumen, for example 650 kg (or less) is sprayed with steam in the mixer.
  • the rest, or 3,250 kg / h, is added to the mixing screw with preheated coal. This produces a charcoal-binder mixture suitable for either pelletizing or pounding. by recycling the soot from the dry dust collector.
  • the invention has been described with regard to a fluidization drying and / or preheating installation. It also applies equally well to a drying and / or preheating installation by co-current drive by hot fumes.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Chemistry (AREA)
  • Solid Fuels And Fuel-Associated Substances (AREA)
  • Coke Industry (AREA)
  • Electrostatic Separation (AREA)
  • Drying Of Solid Materials (AREA)

Description

L'invention concerne un procédé et une installation de traitement par séchage et/ou chauffage par fluidisation et/ou entraînement gazeux d'un matériau combustible granuleux et/ou pulvérulent, tel qu'un charbon à sécher et/ou préchauffer pour l'enfournement en fours à coke de charbons peu cokéfiants par les techniques dites d'enfournement en sec et d'enfournement en préchauffé, ou toute autre application en vue d'un traitement physique ou chimique ultérieur.The invention relates to a process and an installation for treatment by drying and / or heating by fluidization and / or gaseous entrainment of a granular and / or pulverulent combustible material, such as a coal to be dried and / or preheated for charging. in coke ovens of low-coking coals by the techniques known as dry charging and preheated charging, or any other application for subsequent physical or chemical treatment.

Des procédés et installations du type que l'invention se propose de perfectionner sont décrits, par exemple, dans les demandes de brevets français FR-A-2 207 592, 2281 971,2378081 et 2 376 201.Processes and installations of the type that the invention proposes to perfect are described, for example, in French patent applications FR-A-2 207 592, 2281 971, 2378081 and 2 376 201.

Le préchauffage des fines de charbon implique d'utiliser des fumées exemptes d'oxygène, et à une température ne devant pas excéder 500 à 800°C environ. Pour atteindre ce résultat, il a été proposé de recycler dans la chambre de combustion, où l'on réalise une combustion neutre, une partie des fumées ayant servi au préchauffage.The preheating of coal fines involves the use of oxygen-free fumes, and at a temperature not to exceed approximately 500 to 800 ° C. To achieve this result, it has been proposed to recycle in the combustion chamber, where neutral combustion is carried out, part of the fumes used for preheating.

Pour tirer le meilleur parti de l'enfournement en se ou de l'enfournement en préchauffé, les particules de charbon doivent être finement broyées, par exemple 80% et même 90% inférieurs à 2 mm. Ces fines particules de charbon préchauffées à 250°C sont séparées du fluide d'entraînement au moyen de deux étages de cyclones dont le rendement de captation est de 98 à 99%.To get the most out of the oven or the preheated oven, the carbon particles must be finely ground, for example 80% and even 90% less than 2 mm. These fine particles of coal preheated to 250 ° C. are separated from the entrainment fluid by means of two stages of cyclones, the capture efficiency of which is 98 to 99%.

Le système de traitement des fumées, tel que rappelé permet d'atteindre le résultat mais il ne présente pas que des avantages. En effet les fumées recyclées non épurées, donc encore chargées en fines poussières, sont introduites, par l'intermédiaire d'un ventilateur, dans la chambre de combustion, au niveau du brûleur qui fonctionne en combustion stoéchio- métrique et donc à une température proche de la température théorique qui, pour du gaz de four à coke, dépasse 2 000°C. Les fines particules de charbon peuvent brûler, ou fondre, ce qui n'est pas souhaitable. Dans les dispositifs connus les fumées à la sortie des cyclones doivent être épurées avant rejet à l'atmosphère.The smoke treatment system, as recalled, achieves the result but it does not only have advantages. In fact the un purified recycled fumes, therefore still charged with fine dust, are introduced, by means of a fan, into the combustion chamber, at the level of the burner which operates in stoichiometric combustion and therefore at a close temperature the theoretical temperature which, for coke oven gas, exceeds 2000 ° C. Fine particles of carbon can burn, or melt, which is undesirable. In known devices, the fumes at the outlet of the cyclones must be purified before being released into the atmosphere.

Dans un premier type, comme dans FR-A-2 378 081, on procède à un dépoussiérage à sec sur les fumées évacuées seulement, tandis que dans un second type, comme dans FR-A-2 207 592, la totalité des fumées, recyclées ou non, sont soumises à un dépoussiérage à sec.In a first type, as in FR-A-2 378 081, a dry dusting is carried out on the exhaust fumes only, while in a second type, as in FR-A-2 207 592, all of the fumes, recycled or not, are subjected to dry dusting.

Par ailleurs, lorsque l'installation est en conditions d'attente (par exemple en cas d'incident en amont ou en aval du préchauffeur), la quantité de fumées rejetées à l'atmosphère devient très faible, si bien que, dans le cas du premire type, le dépoussiéreur final, disposé sur la conduite de mise à l'atmosphère, arrive à travailler à débit nul ou très faible. Si le dépoussiéreur est du type humide, par exemple venturi à haute énergie, la diminution du débit de fumées n'est pas gênante. Mais un dépoussiéreur humide est inopportun, car les poussières récupérées sont avantageusement à introduire dans les fines à coke. Avec un dépoussiéreur du type sec (filtre à manches et électrofiltre), la diminution du débit de fumées provoque des condensations et par suite des corrosions dans l'appareil. De plus le dépoussiéreur risque d'être en régime de dépression, entraînant alors des entrées d'air parasite dans l'installation.Furthermore, when the installation is in standby conditions (for example in the event of an incident upstream or downstream of the preheater), the quantity of fumes discharged into the atmosphere becomes very small, so that in the case of the first type, the final dust collector, disposed on the venting pipe, arrives at working at zero or very low flow rate. If the dust collector is of the wet type, for example high-energy venturi, the reduction in the flow of smoke is not a problem. However, a wet dust collector is inappropriate because the dust collected is advantageously to be introduced into the coke fines. With a dry type dust collector (bag filter and electrostatic precipitator), the reduction in the smoke flow causes condensation and consequently corrosions in the device. In addition, the dust collector risks being in a vacuum system, thus causing parasitic air to enter the installation.

Mais si on désire installer un dépoussiéreur à sec dans une installation du second type, il faut que celui-ci soit dimensionné pour traiter le débit maximal de fumées correspondant à la marche normale. Comme il n'est pas nécessaire de dépoussiérer totalement les fumées recyclées à la chambre de combustion bien que ce soit souhaitable, on est obligé de prévoir une installation très coûteuse adaptée audit débit maximal des fumées. Par ailleurs, lorsque les fumées sont épurées à sec au moins avant rejet à l'atmosphère, les poussières récupérées sont avantageuses à réintroduire dans les fines de charbon, c'est-à-aire dans le charbon subissant ou ayant subi le traitement préalable. Mais ces poussières récupérées sont des particules sèches très réactives risquant de s'enflammer immédiatement au contact de l'air et s'envolant très facilement. Il est donc nécessaire de les traiter de façon à les rendre inertes et manipulables. Elles sont difficilement mouillables à l'eau. De plus, les humidifier réduit l'intérêt du dépoussiérage à sec. On a déjà proposé, dans FR-A-1 265 397 d'augmenter la qualité du coke sidérurgique obtenu à partir d'un charbon séché en ajoutant au charbon, avant ou après son séchage, un liant hydrocarboné, constitué par un brai de houille, un brai artificiel ou un bitume, ou encore un extrait ou résidu d'extraction, ledit liant hydrocarboné étant ajouté de façon qu'il prenne une consistance pâteuse ou liquide. Un autre avantage connu de l'introduction de liant hydrocarboné est de réduire la quantité d'envols de poussières au moment du chargement du charbon dans le four à coke. C'est pour la même raison qu'on a également proposé, dans FR-A-2 306 252, d'ajouter le liant hydrocarboné dans l'un des transporteurs du charbon déjà préchauffé et ce juste avant son enfournement pour réduire les envols de poussières lors du chargement dans le four à coke.But if you want to install a dry dust collector in a second type installation, it must be sized to handle the maximum smoke flow corresponding to normal operation. As it is not necessary to completely dust off the recycled fumes in the combustion chamber, although this is desirable, it is necessary to provide a very expensive installation adapted to said maximum flow rate of the fumes. Furthermore, when the fumes are dry purified at least before being discharged into the atmosphere, the recovered dust is advantageous to reintroduce into the coal fines, that is to say into the coal undergoing or having undergone the preliminary treatment. However, this recovered dust is very reactive dry particles which are liable to ignite immediately on contact with air and fly away very easily. It is therefore necessary to treat them so as to make them inert and easy to handle. They are hardly wettable with water. In addition, humidifying them reduces the advantage of dry dusting. It has already been proposed, in FR-A-1 265 397 to increase the quality of the steel coke obtained from a dried coal by adding to the coal, before or after its drying, a hydrocarbon binder, constituted by a pitch of coal. , an artificial pitch or a bitumen, or an extract or extraction residue, said hydrocarbon binder being added so that it takes a pasty or liquid consistency. Another known advantage of the introduction of a hydrocarbon binder is to reduce the quantity of dust flights when the coal is loaded into the coke oven. It is for the same reason that it has also been proposed, in FR-A-2 306 252, to add the hydrocarbon binder in one of the transporters of the already preheated coal and this just before it is placed in the oven to reduce the flight of dust when loading into the coke oven.

Le but principal de l'invention est d'éviter les inconvénients des deux types précités d'installations comportant un dépoussiérage à sec et de proposer un nouveau procédé et une nouvelle installation ayant un dépoussiéreur à sec non surchargé ni surdimensionné, et non sujet à corrosion par risque de débit insuffisant faisant descendre la température en dessous du point de rosée, notamment pendant les périodes d'attente à faible production de chaleur dans l'installation. Autrement dit on désire obtenir l'efficacité de dépoussiérage optimale du dépoussiéreur.The main object of the invention is to avoid the drawbacks of the two aforementioned types of installations comprising dry dust removal and to propose a new process and a new installation having a dry dust collector that is not overloaded or oversized, and not subject to corrosion by risk of insufficient flow causing the temperature to drop below the dew point, especially during waiting periods with low heat production in the installation. In other words, it is desired to obtain the optimum dedusting efficiency from the deduster.

Un autre but de l'invention est de proposer une solution au problème de la récupération, de la manutention et du réemploi des poussières récupérées grâce à un traitement particulier qui va être exposé.Another object of the invention is to propose a solution to the problem of the recovery, handling and re-use of the dust recovered by means of a particular treatment which will be explained.

Les buts de l'invention sont atteints par un procédé de traitement par séchage et/ou préchauffage par entraînement et/ou fluidisation d'un matériau combustible granuleux ou pulvérulent, dans lequel on sèche et/ou chauffe le matériau par entraînement et/ou fluidisation en l'introduisant dans une enceinte d'entraînement et/ou fluidisation, où on établit un régime d'entraînement et/ou fluidisation à température donnée au moyen d'un agent gazeux neutre obtenu à température et en quantités régulées dans une chambre de combustion, et d'où on extrait le matériau séché et/ou chauffé par transport pneumatique au sein de l'agent gazeux effluent, puis on sépare ledit matériau dudit agent gazeux effluent en répartissant ledit agent gazeux en quantités régulées entre une conduite de recyclage vers la chambre de combustion et une sortie d'évacuation pour le surplus, procédé dans lequel l'agent gazeux en surplus est dépoussiéré par un dépoussiéreur à sec, grâce au fait qu'on dépoussière également à sec dans ce dernier une partie réglée de l'agent gazeux recyclé, au moins pendant les périodes d'interruption d'introduction du matériau combustible granuleux ou pulvérulent, et on règle la quantité d'agent gazeux recyclé et dépoussiéré en imposant au débit de gaz dépoussiéré une valeur de consigne fixe.The objects of the invention are achieved by a method of treatment by drying and / or preheating by entrainment and / or fluidization of a granular or pulverulent combustible material, in which the material is dried and / or heated by entrainment and / or fluidization by introducing it into a drive and / or fluidization enclosure, where a drive and / or fluidization regime is established at a given temperature by means of a neutral gaseous agent obtained at temperature and in regulated quantities in a combustion chamber , and from which the dried and / or heated material is extracted by pneumatic transport within the effluent gas agent, then said material is separated from said effluent gas agent by distributing said gaseous agent in regulated quantities between a recycling line to the combustion chamber and a discharge outlet for the surplus, process in which the surplus gaseous agent is dusted by a dry dust collector, thanks to the fact that dust is also removed at s ec in the latter a regulated part of the recycled gaseous agent, at least during the periods of interruption of introduction of the granular or pulverulent combustible material, and the quantity of gaseous agent recycled and dedusted is adjusted by imposing on the gas flow rate dusted a fixed setpoint.

De cette façon le dépoussiéreur à sec travaille en toutes circonstances à débit gazeux constant et à température convenable, déjà réglée par ailleurs par réglage du brûleur de la chambre de combustion. Pour chaque type de poussière, il y a une efficacité optimale obtenue par une vitesse de passage de gaz correspondante.In this way the dry dust collector works in all circumstances at a constant gas flow rate and at a suitable temperature, already already regulated by adjusting the burner of the combustion chamber. For each type of dust, there is an optimal efficiency obtained by a corresponding gas passage speed.

Le second but est atteint par un procédé dans lequel on injecte à l'état liquide un liant hydrocarboné d'appoint dans le combustible solide à l'une des étapes de traitement, grâce au fait qu'on piège dans un liquide carboné chaud les poussières captées par le dépoussiéreur à sec et on utilise ledit liquide carboné chaud chargé desdites poussières comme liant hydrocarboné d'appoint, au moins partiel.The second object is achieved by a process in which a liquid hydrocarbon binder is injected into the solid fuel in one of the treatment stages, thanks to the fact that the dust is trapped in a hot carbonaceous liquid. captured by the dry dust collector and said hot carbonaceous liquid charged with said dust is used as an auxiliary hydrocarbon binder, at least partially.

Selon un mode de réalisation avantageux, on injecte ledit liquide carboné chaud, chargé desdites poussières, dans le matériau combustible après le point de sortie de séparation d'avec le gaz caloporteur ayant servi d'agent effluent gazeux de transport.According to an advantageous embodiment, said hot carbonated liquid, charged with said dust, is injected into the combustible material after the point of separation from the heat transfer gas having served as a gaseous effluent transport agent.

Il est avantageux que le liquide carboné soit très mobile et très mouillant pour les poussières. A cet effet il sera avantageusement choisi dans le groupe constitué par les hydrocarbures liquides à température ambiante ou après réchauffage, tels que le fuel lourd, les bitumes pétroliers. De cette façon on obtiendra un mélange pompable permettant son incorporation au charbon préchauffé, comme indiqué précédemment.It is advantageous for the carbonated liquid to be very mobile and very wetting for dust. To this end, it will advantageously be chosen from the group consisting of hydrocarbons liquid at room temperature or after reheating, such as heavy fuel oil, petroleum bitumens. In this way we will obtain a pumpable mixture allowing its incorporation into preheated coal, as indicated above.

Les buts de l'invention sont également atteints par une installation de séchage et/ou chauffage par entraînement et/ou fluidisation d'un matériau combustible granuleux ou pulvérulent comportant:

  • - un dispositif de séchage et/ou chauffage comprenant:
  • - une enciente de séchage et/ou chauffage par entraînement et/ou fluidisation, à la base de laquelle débouche un conduit d'amenée d'un agent gazeux d'entraînement et/ou fluidisation,
  • - des moyens d'introduction dans ladite enceinte du matériau à sécher et/ou chauffer,
  • - une conduite d'entraînement du matériau séché et/ou chauffé,
  • -des moyens de séparation du matériau granuleux ou pulvérulent d'avec l'agent gazeux de fluidisation,
  • - une chambre de combustion pour la production de l'agent gazeux d'entraînement et/ou de fluidisation dirigé vers le conduit d'amenée à ladite enceinte, ladite chambre de combustion comportant au moins un brûleur,
  • -des moyens de régulation du débit du combustible liquide ou gazeux amené au brûleur asservis à des moyens de mesure de température dans ladite enceinte,
  • - des moyens de recyclage d'une partie de l'agent gazeux d'entraînement et/ou fluidisation dans la chambre de combustion en quantité régulée par une ou des vannes de répartition entre une conduite de recyclage et une conduite d'évacuation des fumées,
  • - un dépoussiéreur des fumées évacuées qui, pour une meilleure séparation finale des particules d'avec l'agent d'entraînement et/ou fluidisation, est constitué par un filtre électrostatique, laquelle installation comporte en outre:
  • - un premier moyen de répartition de l'agent gazeux d'entraînement et/ou fluidisation entre un circuit de recyclage direct et un circuit commun de recyclage et d'évacuation à travers le filtre électrostatique,
  • - un moyen de régulation à une valeur de consigne de la quantité d'agent gazeux d'entraînement et/ou fluidisation traversant le filtre électrostatique, et
  • - un régulateur de pression par mise à l'atmosphère d'une partie de l'agent gazeux dépoussiéré.
The aims of the invention are also achieved by a drying and / or heating installation by entrainment and / or fluidization of a granular or pulverulent combustible material comprising:
  • - a drying and / or heating device comprising:
  • - a drying and / or heating incient by entrainment and / or fluidization, at the base of which opens a supply conduit for a gaseous entrainment and / or fluidization agent,
  • means for introducing into said enclosure the material to be dried and / or heated,
  • - a line for driving the dried and / or heated material,
  • means for separating the granular or pulverulent material from the gaseous fluidizing agent,
  • a combustion chamber for the production of the gaseous entrainment and / or fluidization agent directed towards the supply line to said enclosure, said combustion chamber comprising at least one burner,
  • means for regulating the flow of liquid or gaseous fuel supplied to the burner, subject to temperature measurement means in said enclosure,
  • means for recycling part of the gaseous entrainment and / or fluidization agent in the combustion chamber in a quantity regulated by one or more distribution valves between a recycling pipe and a smoke evacuation pipe,
  • - a dust collector for the exhausted fumes which, for better final separation of the particles from the entrainment and / or fluidization agent, consists of an electrostatic filter, which installation further comprises:
  • a first means of distributing the gaseous entraining and / or fluidizing agent between a direct recycling circuit and a common recycling and evacuation circuit through the electrostatic filter,
  • a means of regulating the quantity of gaseous entrainment and / or fluidization agent passing through the electrostatic filter at a set value, and
  • - a pressure regulator by venting part of the dusted gaseous agent.

Il est avantageux que le moyen de régulation de la quantité d'agent gazeux traversant le filtre agisse directement sur ledit premier moyen de répartition de l'agent gazeux.It is advantageous for the means for regulating the quantity of gaseous agent passing through the filter to act directly on said first means for distributing the gaseous agent.

Le but de l'invention est également atteint par une installation du type précédent comprenant un moyen d'introduction de liant hydrocarboné liquide dans le combustible solide à l'une des étapes du traitement et un dispositif de piégeage en liquide carboné des poussières captées par le dépoussiéreur.The object of the invention is also achieved by an installation of the above type com taking a means for introducing liquid hydrocarbon binder into the solid fuel at one of the stages of the treatment and a device for trapping in carbonaceous liquid the dust collected by the dust collector.

Il est avantageux que les moyens d'introduction du liant hydrocarboné liquide dans le combustible solide, tel que charbon, débouchent en aval du point de sortie dudit combustible du dispositif séparateur charbon/gaz, de préférence dans une vis mélangeuse de transport, telle qu'il est connu en soi.It is advantageous that the means for introducing the liquid hydrocarbon binder into the solid fuel, such as coal, open downstream of the point of exit of said fuel from the coal / gas separator device, preferably in a mixing conveyor screw, such as it is known per se.

il est également avantageux que l'installation comporte, outre ce moyen d'introduction du liant hydrocarboné liquide dans le combustible, un moyen contigu classique d'introduction directe de liant hydrocarboné et/ou liquide carboné.it is also advantageous that the installation comprises, in addition to this means of introducing the liquid hydrocarbon binder into the fuel, a conventional contiguous means of direct introduction of hydrocarbon binder and / or carbonaceous liquid.

D'autres caractéristiques et avantages ressortiront de la description, qui sera donné ci-après uniquement à titre d'exemple, d'un mode de réalisation de l'invention. On se reportera, à cet effet, aux dessins annexés, dans lesquels

  • - la figure 1 est un schéma simplifié d'une installation conforme à l'invention,
  • - la figure 2 est un schéma de détail du dispositif de piégeage des poussières captées par le dépoussiéreur.
Other characteristics and advantages will emerge from the description, which will be given below by way of example only, of an embodiment of the invention. For this purpose, reference is made to the accompanying drawings, in which
  • FIG. 1 is a simplified diagram of an installation in accordance with the invention,
  • - Figure 2 is a detailed diagram of the device for trapping dust collected by the dust collector.

Une installation de préchauffage de charbon comporte un sécheur-broyeur préchauffeur désigné dans son ensemble par 10. Celui-ci comprend une conduite 11 verticale d'entraînement ascendant du charbon par des fumées chaudes, un transporteur à vis 12 amenant le charbon d'une trémie 13 à la conduite 11 en un point situé au-dessus d'un venturi 14 prévu dans la partie inférieure de la conduite 11.A coal preheating installation comprises a preheater dryer-mill designated as a whole by 10. This comprises a vertical pipe 11 for driving the coal up by hot smoke, a screw conveyor 12 bringing the coal from a hopper 13 to the pipe 11 at a point situated above a venturi 14 provided in the lower part of the pipe 11.

Au-dessus de la conduite 11 est disposée une enceinte de fluidisation 15 dans la partie inférieure de laquelle débouche ladite conduite 11, en dessous d'un broyeur rotatif à percussion 16.Above the pipe 11 is disposed a fluidization enclosure 15 in the lower part of which opens the said pipe 11, below a rotary impact mill 16.

Au sommet de l'enceinte 15 prend naissance une conduite 17 d'entraînement du charbon préchauffé et broyé dans l'enceinte 15. La conduite 17 permet d'entraîner ce charbon vers une batterie de cyclones 18 comportant deux étages, cyclone primaire et cyclones secondaires, à la pointe desquels on récupère ce charbon sur un transporteur à vis 19 vers une trémie de stockage en vue de son enfournement ultérieur dans un four à coke. Au vortex des cyclones 18, on récupère les fumées dans une conduite 21 de recyclage au moyen d'un ventilateur 22.At the top of the enclosure 15 is born a pipe 17 for driving the preheated and ground coal in the enclosure 15. The pipe 17 makes it possible to drive this coal towards a battery of cyclones 18 comprising two stages, primary cyclone and secondary cyclones , at the tip of which this coal is recovered on a screw conveyor 19 to a storage hopper with a view to its subsequent charging in a coke oven. At the vortex of cyclones 18, the fumes are recovered in a recycling pipe 21 by means of a fan 22.

L'installation comporte une chambre de combustion 20 débouchant à la base de la conduite ascendante 11. Cette chambre de combustion est alimentée par un double brûleur 30 en tous points semblable à celui qui est décrit dans FR-A-2 378 081, c'est-à-dire qu'il comprend un brûleur 31, appelé brûleur principal, en fonctionnement normal pour le préchauffage du charbon, l'autre 36, appelé brûleur d'appoint, pour la mise en attente de l'installation en cas d'interruption de l'alimentation en charbon par le transporteur 12. Chaque brûleur est pourvu de moyens de régulation de l'air comburant pour que la combustion soit sensiblement neutre et comporte en outre des moyens de régulation du combustible asservi à des mesures de température dans l'enceinte de fluidisation. Le ventilateur 22 recycle par des gaînes 23 une partie des fumées prélevées en 21 en quantité régulée telle que la vitesse du flux gazeux total soit maintenue constante dans l'enceinte de fluidisation 15. Un ensemble de régulation 48 permet de régler la combustion au double brûleur 30 en fonction de la température mesurée en 43 dans l'enceinte 15.The installation comprises a combustion chamber 20 opening at the base of the ascending pipe 11. This combustion chamber is supplied by a double burner 30 in all points similar to that which is described in FR-A-2 378 081, it that is to say that it comprises a burner 31, called the main burner, in normal operation for the preheating of the coal, the other 36, called the auxiliary burner, for putting the installation on standby in the event of interruption of the supply of coal by the conveyor 12. Each burner is provided with means for regulating the combustion air so that the combustion is substantially neutral and also comprises means for regulating the fuel subject to temperature measurements in the fluidization enclosure. The fan 22 recycles by ducts 23 a portion of the fumes withdrawn in 21 in a regulated quantity such that the speed of the total gas flow is kept constant in the fluidization enclosure 15. A regulation assembly 48 makes it possible to regulate the combustion with the double burner 30 as a function of the temperature measured at 43 in enclosure 15.

On a décrit jusqu'ici l'essentiel de ce qui est connu par les procédés et dispositifs connus, les dispositifs annexes de commande et régulation représentés dans la moitié gauche de la figure et non rappelés ci-dessus étant également connus en soi, par exemple par la demande de brevet français publiée N° 2 378 081, sans qu'il soit plus besoin de les décrire à nouveau.The main part of what is known by the known methods and devices has been described so far, the auxiliary control and regulation devices shown in the left half of the figure and not recalled above being also known per se, for example by published French patent application No. 2,378,081, without there being any need to describe them again.

Un dépoussiéreur électrostatique à sec 24 est alimenté par une conduite 2, dérivée de la conduite 21 de recyclage, d'ou elle se sépare de la partie 3 de la conduite 21. Côté effluent gazeux, le dépoussiéreur 24 alimente une conduite d'évacuation 5 et une autre conduite de recyclage 7 rejoignant la conduite 3 en amont du ventilateur de recyclage 22. Des vannes, à savoir 9 sur la conduite 2, 6 sur la conduite d'évacuation 5 et 42 sur la conduite 3 dans sa partie court-circuitant le filtre 24, permettent de répartir à volonté le débit gazeux normal V de la conduite 21 entre un débit V1 de recyclage direct dans la conduite 3, un débit V2 de recyclage avec dépoussiérage à travers la conduite 7 qui rejoint la conduite 3 et un débit V3 d'effluent gazeux évacué.A dry electrostatic dust collector 24 is supplied by a line 2, derived from the recycling line 21, from where it separates from part 3 of the line 21. On the gaseous effluent side, the dust collector 24 supplies a discharge line 5 and another recycling pipe 7 joining the pipe 3 upstream of the recycling fan 22. Valves, namely 9 on the pipe 2, 6 on the discharge pipe 5 and 42 on the pipe 3 in its short-circuiting part the filter 24, make it possible to distribute at will the normal gas flow rate V of the line 21 between a flow rate V 1 of direct recycling in the line 3, a flow rate V 2 of recycling with dedusting through the line 7 which joins the line 3 and a flow rate V 3 of evacuated gaseous effluent.

La perte de charge des cyclones 18, fonction du débit gazeux V, est maintenue constante, comme il est connu en soi, par l'action d'une vanne 1. Le débit V3 d'effluent gazeux à évacuer est réglé par la vanne 6 qui agit en régulateur de pression pour maintenir constante la pression dans l'électrofiltre 24. Selon l'invention, une plus ou moins grande partie du débit recyclé dans la chambre de combustion 20 mesurée en 4 est dérivée pour être définitivement évacué en 5. A cet effet, on mesure la dépression observée entre l'entrée et la sortie du dépoussiéreur, la mesure est introduite dans un régulateur 37 qui commande la vanne 42 et/ou la vanne 9 de façon à assurer le respect d'une valeur de consigne pour la dépression entre entrée et sortie du dépoussiéreur.The pressure drop of cyclones 18, a function of the gas flow rate V, is kept constant, as it is known per se, by the action of a valve 1. The flow rate V 3 of gaseous effluent to be discharged is adjusted by the valve 6 which acts as a pressure regulator to keep the pressure in the electrostatic precipitator 24 constant. According to the invention, a greater or lesser part of the flow recycled in the combustion chamber 20 measured at 4 is diverted to be definitively discharged at 5. To this end, the vacuum observed between the inlet and the outlet of the dust collector is measured, the measurement is introduced into a regulator 37 which controls the valve 42 and / or the valve 9 so as to ensure compliance with a set value for vacuum between inlet and outlet of the dust collector.

Dans tout ce qui a été dit et dans tout ce qui suit, on remarquera qu'on doit distinguer clairement l'étage de séparation et l'étage de dépoussiérage. L'étage de séparation, constituée par les cyclones 18, a pour objet de séparer le charbon granuleux et/ou pulvérulent séché et/ou chauffé et les gaz d'entraînement en acceptant le minimum de perte de l'un et de l'autre. L'étage de dépoussiérage a pour objet de restituer à l'atmosphère ou de recycler un gaz aussi exempt que possible des poussières, par exemple environ <0,05 mm, entraînées au vortex des cyclones.In all that has been said and in all that follows, it will be noted that a clear distinction must be made between the separation stage and the dedusting stage. The purpose of the separation stage, constituted by the cyclones 18, is to separate the granular and / or powdered coal which is dried and / or heated and the entrainment gases by accepting the minimum loss of one and the other. The purpose of the dedusting stage is to restore to the atmosphere or to recycle a gas as free as possible from the dust, for example about <0.05 mm, entrained in the vortex of the cyclones.

On prendra comme exemple une installation de préchauffage d'une capacité de traitement de 72 t/h. Le débit total de fumées V soit 66 000 m3N/h qui circule dans le préchauffeur est maintenu constant par ajustement du débit de fumées V1 + V2 recyclées dans la chambre de combustion au moyen du ventilateur 22. Le débit excédentaire V3 est rejeté à l'atmosphère.An example would be a preheating installation with a processing capacity of 72 t / h. The total smoke flow V, ie 66,000 m 3 N / h which circulates in the preheater, is kept constant by adjusting the flow of smoke V1 + V2 recycled into the combustion chamber by means of the fan 22. The excess flow V3 is rejected at the atmosphere.

On a V = V1 + V2 + V3 = constante et V2 + V3 = constante.We have V = V1 + V2 + V3 = constant and V2 + V3 = constant.

Lorsque l'installation fonctionne à l'allure nominale, le volume V3 est de 24 000 m3N/h de fumées. C'est par définition le débit nominal de l'électrofiltre. Le débit V2 devra être nul et le débit de fumées recyclées sera alors V1 = 42 000 m3N/h.When the installation operates at nominal speed, the volume V3 is 24,000 m 3 N / h of smoke. This is by definition the nominal flow rate of the electrostatic precipitator. The flow rate V2 must be zero and the flow rate of recycled smoke will then be V1 = 42,000 m 3 N / h.

Lorsque l'installation fonctionne à une puissance inférieure à la puissance nominale, le débit V3 devra diminuer, par exemple à demi-puissance; le débit V3 sera alors de 12 000 m3N/h, le débit V2 sera de 12 000 m3N/h et le débit de fumées recyclées dans la chambre de combustion sera de V1 + V2 = 54 000 m 3.When the installation operates at a power lower than the nominal power, the flow rate V3 must decrease, for example at half power; the flow rate V3 will then be 12,000 m 3 N / h, the flow rate V2 will be 12,000 m 3 N / h and the flow rate of recycled fumes in the combustion chamber will be V1 + V2 = 54,000 m 3 .

Lorsque l'installation est en condition d'attente, pour interruption d'approvisionnement en charbon, le débit de fumées V3 devra être très faible (600 m3/h environ). Il correspondra au débit calorifique du brûleur pilote. Le débit de fumées recyclées dans la chambre de combustion sera alors V2 + V1 avec V2 = 24 000 m3N/h et V1 = 41 400 m3N/h.When the installation is in standby condition, for interruption of coal supply, the V3 smoke flow must be very low (approximately 600 m 3 / h). It will correspond to the heat output of the pilot burner. The flow of recycled smoke in the combustion chamber will then be V2 + V1 with V2 = 24,000 m 3 N / h and V1 = 41,400 m 3 N / h.

Grâce à l'invention, on élimine ainsi les inconvénients précédemment cités, relatifs à l'efficacité de l'électrofiltre et à la condensation des fumées entraînant la corrosion de l'installation.Thanks to the invention, the above-mentioned drawbacks relating to the efficiency of the electrostatic precipitator and to the condensation of the fumes causing corrosion of the installation are thus eliminated.

Conformément à l'invention, les poussières captées dans le dépoussiéreur à sec sont envoyées dans le transporteur à vis 19 à travers un dispositif de piégeage en liquid carboné, simplement figuré par le rectangle 60 à la figure 1, mais représenté schématiquement dans sa totalité à la figure 2.In accordance with the invention, the dust collected in the dry dust collector is sent into the screw conveyor 19 through a carbonaceous liquid trapping device, simply shown by the rectangle 60 in FIG. 1, but shown schematically in its entirety at Figure 2.

Au point de décharge du dépoussiéreur à sec 24 est prévue une vis d'Archimède 62 approvisionnant un dispositif de malaxage de d'homogénéisation 63 de capacité suffisante alimenté en produit hydrocarboné liquide et chaud par une conduite 64. Le mélange est mis en circulation fermée dans la conduite 64 au moyen d'une pompe 67. L'appoint de liquide pur se fait par une conduite 68 dans le dispositif 63. Une fraction de mélange, correspondant à la production de suies associée à la quantité de liquide suffisante pour la manutention et nécessaire pour le procédé, est prélevée du circuit de circulation fermée et amenée par une conduite 70 vers le point d'utilisation.At the discharge point of the dry dust collector 24 is provided an Archimedes screw 62 supplying a homogenization kneading device 63 of sufficient capacity supplied with liquid and hot hydrocarbon product via a pipe 64. The mixture is put into circulation closed in line 64 by means of a pump 67. The pure liquid is topped up by a line 68 in the device 63. A fraction of mixture, corresponding to the production of soot associated with the quantity of liquid sufficient for handling and necessary for the process, is taken from the closed circulation circuit and brought by a pipe 70 to the point of use.

Dans l'exemple décrit, le point d'utilisation est le convoyeur à vis 19 précité. Il est avantageux de prévoir un point supplémentaire d'introduction du liquide carboné en 74 sur la vis mélangeuse 19.In the example described, the point of use is the aforementioned screw conveyor 19. It is advantageous to provide an additional point of introduction of the carbonaceous liquid at 74 on the mixing screw 19.

L'ensemble des conduites est réchauffé au moyen de vapeur, les conduites peuvent être balayées à la vapeur pour être purgées et il est avantageux d'asservir la proportion du mélange liquide/suies au débit de charbon préchauffé, comme il est connu en soi pour l'appoint de liant hydrocarboné à un charbon préchauffé.All the pipes are heated by steam, the pipes can be swept with steam to be purged and it is advantageous to control the proportion of the liquid / soot mixture to the flow of preheated coal, as is known per se adding hydrocarbon binder to preheated coal.

On voit que l'invention permet de récupérer sans humidification à l'eau les suies récupérées dans un dépoussiéreur à sec, de manipuler les suies sans danger et sans pollution et de les transporter en un point d'utilisation à une hauteur compatible avec la pression de refoulement de la pompe.It can be seen that the invention makes it possible to recover the soot recovered in a dry dust collector without humidifying with water, to handle the soot safely and without pollution and to transport it to a point of use at a height compatible with the pressure. pump discharge.

Dans le cas de l'enfournement préchauffé sous forme de fines, l'invention permet en outre de recycler les suies de dépoussiérage à sec dans la pâte à coke préchauffée avec le fuel. Mais l'invention permet également de limiter les envols lors de l'enfournement et de limiter les envols lors de l'enfournement avec le mélange fuelsuies.In the case of preheated charging in the form of fines, the invention also makes it possible to recycle the sootings of dry dedusting in the coke paste preheated with fuel. However, the invention also makes it possible to limit takeoffs during charging and to limit takeoffs during charging with the fuel mixture.

A titre d'exemple, pour une installation permettant de préchauffer 72 t/h de charbon, il est produit à l'électrofiltre 100 à 200 kg/h de suies. On rajoutera au total environ 0,8% en poids de fuel lourd N° 2 chauffé à 150°C (pourcentage rapporté à la quantité totale de charbon préchauffé).For example, for an installation enabling 72 t / h of coal to be preheated, 100 to 200 kg / h of soot is produced using an electrostatic precipitator. A total of approximately 0.8% by weight of heavy fuel oil No. 2 heated to 150 ° C. will be added to the total (percentage based on the total amount of preheated coal).

Une fraction du fuel à raison de 400 kg/h environ est pulvérisée à la vapeur dans le mélangeur. Le reste, soit 150 kg/h environ est pulvérisé pur sur le charbon préchauffé dans la vis mélangeuse.A fraction of the fuel at the rate of approximately 400 kg / h is sprayed with steam in the mixer. The rest, about 150 kg / h, is sprayed pure onto the preheated coal in the mixing auger.

Dans le cas de l'enfournement préchauffé de fines de charbon compactées soit par bouletage, soit par pilonnage, l'invention permet en outre de recycler les suies dans la pâte à coke préchauffée avec un bitume pétrolier, qui par ailleurs, utilisé seul, aurait permis d'apporter à la pâte à coke préchauffée la cohésion nécessaire pour former soit des boulets, soit un pain pilonné à partir de charbon sec et chaud et de préparer soit des boulets, soit un pain pilonné après avoir ajouté dans la vis mélangeuse la quantité totale de liant nécessaire dont tout ou partie aura servi à manipuler les suies.In the case of the preheated charging of coal fines compacted either by pelletizing or by pounding, the invention also makes it possible to recycle the soot in the coke paste preheated with a petroleum bitumen, which, moreover, used alone, would have allowed to bring to the preheated coke paste the cohesion necessary to form either balls, or a bread pounded from dry and hot coal and to prepare either balls or a pounded bread after adding in the mixing screw the quantity total of necessary binder of which all or part will have been used to handle the soot.

A titre d'exemple, pour l'installation précitée permettant de préchauffer 72 t/h de charbon, soit environ 65 t/h de charbon sec, il est produit à l'électrofiltre 100 à 200 kg/h de suies. On rajoute par exemple au total 6% en poids d'un bitume pétrolier chauffé à 150°C (pourcentage rapporté à la quantité totale de charbon préchauffé). Une fraction du bitume, par exemple 650 kg (ou moins), est pulvérisée à la vapeur dans le mélangeur. Le reste, soit 3 250 kg/h est ajouté sur la vis mélangeuse au charbon préchauffé. On obtient ainsi un mélange charbon- liant apte soit au bouletage, soit au pilonnage en ayant recyclé les suies du dépoussiéreur à sec.For example, for the aforementioned installation enabling 72 t / h of coal to be preheated, or approximately 65 t / h of dry coal, 100 to 200 kg / h of soot is produced using an electrostatic precipitator. For example, a total of 6% by weight of a petroleum bitumen heated to 150 ° C. is added (percentage based on the total quantity of preheated coal). A fraction of the bitumen, for example 650 kg (or less), is sprayed with steam in the mixer. The rest, or 3,250 kg / h, is added to the mixing screw with preheated coal. This produces a charcoal-binder mixture suitable for either pelletizing or pounding. by recycling the soot from the dry dust collector.

L'invention a été décrite en regard d'une installation de séchage et/ou préchauffage par fluidisation. Elle s'applique tout aussi bien à une installation de séchage et/ou préchauffage par entraînement à co-courant par des fumées chaudes.The invention has been described with regard to a fluidization drying and / or preheating installation. It also applies equally well to a drying and / or preheating installation by co-current drive by hot fumes.

En définitive, les avantages du procédé et de l'installation selon l'invention sont les suivants:

  • - possibilité de profiter en toutes circonstances de l'efficacité des dépoussiéreurs du type électrostatique sec dont la consommation énergétique est très faible.
  • - l'efficacité de l'électrofiltre est optimale quelle que soit l'allure de l'installation de préchauffage.
  • - le rendement pondéral en charbon préchauffé est amélioré.
  • - le fonctionnement de l'installation dans les conditions d'attente devient plus souple et plus sûr et est réglable automatiquement.
  • - on réincorpore facilement dans le charbon traité les poussières bien qu'elles se présentent à l'état sec et peu mouillable.
Ultimately, the advantages of the method and of the installation according to the invention are as follows:
  • - possibility of taking advantage in all circumstances of the effectiveness of dust collectors of the dry electrostatic type whose energy consumption is very low.
  • - the efficiency of the electrostatic precipitator is optimal whatever the appearance of the preheating installation.
  • - the weight yield of preheated coal is improved.
  • - the operation of the installation in waiting conditions becomes more flexible and safer and is adjustable automatically.
  • - The dust is easily reincorporated into the treated coal, although it is present in the dry and not very wettable state.

Claims (12)

1. A process for treating by drying and/ or heating by entrainment and/or fluidisation of a granular or pulverulant combustible material, in which the combustible material is dried and/or heated by entrainment and/or fluidisation by being introduced into an enclosure for entrainment and/or fluidisation, where a state of entrainment and/or fluidisation is established at a given temperature by means of a neutral gaseous agent produced at a regulated temperature and in a regulated quantity in a combustion chamber, and from where the dried and/or heated combustible material is withdrawn by pneumatic transport within the effluent gaseous agent, and in which the said combustible material is then separated from the said effluent gaseous agent by distribution of the said gaseous agent in regulated quantities between a duct for recycling towards the combustion chamber and a discharge outlet for the excess, process in which the excess gaseous agent is dedusted by a dry dust separator, characterised in that a controlled proportion of the recycled gaseous agent is also dedusted dry in the same dust separator, at least during periods of interruption of the introduction of the granular or pulverulant combustible material, and in that the quantity of the recycled and dedusted gaseous agent is controlled by imposing a fixed set value on the flow of the dedusted gas.
2. A process according to Claim 1, in which an additional hydrocarbon binder is injected in the liquid state into the solid combustible material at one of the treatment stages, characterised in that the dust caught by the dry dust separator is trapped in a hot carbonaceous liquid, and the said hot carbonaceous liquid carrying the said dust is then employed as an additional hydrocarbon binder, at least in part.
3. A process according to Claim 2, characterised in that the said hot carbonaceous liquid carrying the said dust is injected into the solid combustible material after the point of exit from separation from the heat-exchanger gas which has been employed as a gaseous effluent transport agent.
4. A process according to Claim 2, characterised in that the carbonaceous liquid is from the group consisting of hydrocarbons which are liquid at ambient temperature or after being reheated.
5. An installation for drying and/or heating by entrainment and/or fluidisation of a granular or pulverulent combustible material for carrying out the process according to Claim 1, consisting of:
- device (10) for drying and/or heating comprising:
-an enclosure (15) for drying and/or heating by entrainment and/or fluidisation, into the base of which issues a duct (11) for entry of a gaseous agent for entrainment and/or fluidisation,
- means (12) for introducing material to be dried and/or heated into the said enclosure,
- a duct (17) for entrainment of the dried and/or heated material,
- means (18) for separating the granular or pulverulent material from the gaseous fluidisation agent,
- a combustion chamber (20) for the production of the gaseous agent for entrainment and/or fluidisation, which is directed towards the duct for entry into the said enclosure, the said combustion chamber comprising at least one burner (30),
- means for regulating (48) the flow of the liquid or gaseous combustible material supplied to the burner, which are controlled by means (43) for measurement of temperature in the said enclosure,
- means (21, 22, 23) for recycling a proportion of the gaseous agent for entrainment and/or fluidisation into the combustion chamber (20) in a quantity which is regulated by one or more distribution valves between a recycle duct and a fume discharge duct,
- a dust separator for discharged fumes which, for a better final separation of the particles from the entrainment and/or fluidisation agent, consists of an electrostatic filter (24}, characterised in that if comprises:
- first means (37) for distribution of the gaseous agent for entrainment and/or fluidisation between a direct recycle duct (3) and a common duct (2) for recycling and for discharge through the electrostatic filter (24),
- means (9) for controlling at a set value the quantity of the gaseous agent for entrainment and/or fluidisation passing through the electrostatic filter (24), and
- a pressure regulator (6) for releasing to the atmosphere a part of the dedusted gaseous agent.
6. An installation according to Claim 5, characterised in that the means for regulating the quantity of the gaseous agent passing through the filter (24) acts directly on the said first means of distribution of the gaseous agent.
7. An installation according to Claim 5, comprising a means of introducing liquid hydrocarbonaceous binder into the coal at one of the treatment stages, characterised in that it comprises a device (60) for trapping in a carbonaceous liquid the dust caught by the dust separator (24).
8. An installation according to Claim 7, characterised in that it comprises means (67) for recycling the mixture of carbonaceous liquid and dust, and means (70) for injecting this mixture into the circuit of the means for introducing the hydrocarbonaceous binder into one of the treatment stages.
9. An installation according to Claim 8, characterised in that the means (70) for introducing the liquid hydrocarbonaceous binder into the coal issues downstream of the exit point of the coal from the device for separating coal from gas.
10. An installation according to Claim 9, comprising, at the exit of coal from the device separating coal from gas, a mixing screw- conveyor, characterised in that the means for introducing the hydrocarbonaceous binder debouch into the said mixing screw (19).
11. An installation according to Claim 7, characterised in that it comprises a recycling pump (67) and ducting (64) for recycling the contents of the trapping device (60).
12. An installation according to Claim 8, characterised in that it comprises, in addition to the first means (70) for introducing the liquid hydrocarbonaceous binder into the coal, a second adjoining means (74) of direct introduction of hydrocarbonaceous binder and/or carbonaceous liquid.
EP80401365A 1979-09-26 1980-09-25 Process for treating by drying and/or heating combustible granular and/or pulverulent material, and assembly for carrying out the process Expired EP0026707B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT80401365T ATE5082T1 (en) 1979-09-26 1980-09-25 METHOD OF TREATMENT BY DRYING AND/OR HEATING PARTICULATE AND/OR POWDERY COMBUSTIBLE MATERIAL AND PLANT FOR CARRYING OUT THE PROCESS.

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
FR7923920 1979-09-26
FR7923920A FR2465774A1 (en) 1979-09-26 1979-09-26 Drying and heating granular or powdered fuels - with splitting of recycled gases so that flow through dust remover is constant
FR8012876A FR2484069A1 (en) 1980-06-10 1980-06-10 Drying and heating granular or powdered fuels - with splitting of recycled gases so that flow through dust remover is constant
FR8012876 1980-06-10

Publications (2)

Publication Number Publication Date
EP0026707A1 EP0026707A1 (en) 1981-04-08
EP0026707B1 true EP0026707B1 (en) 1983-10-19

Family

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Family Applications (1)

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EP80401365A Expired EP0026707B1 (en) 1979-09-26 1980-09-25 Process for treating by drying and/or heating combustible granular and/or pulverulent material, and assembly for carrying out the process

Country Status (10)

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US (1) US4321032A (en)
EP (1) EP0026707B1 (en)
AU (1) AU534099B2 (en)
BR (1) BR8006070A (en)
CA (1) CA1127401A (en)
DE (1) DE3065381D1 (en)
ES (1) ES8200715A1 (en)
IN (1) IN153919B (en)
NO (1) NO802837L (en)
RO (1) RO81931A (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NO164608C (en) * 1988-04-20 1990-10-24 Elkem Technology PROCEDURE FOR THE MANUFACTURE OF METALS OR PROCEDURAL ALLOYS BY DIRECT REDUCTION AND COLUMN FOR TREATMENT OF FINE CORNED MATERIALS WITH GAS.
JP3783071B2 (en) * 2002-07-11 2006-06-07 味の素株式会社 Cosmetic composition
DE102005052753A1 (en) * 2005-11-04 2007-05-10 Polysius Ag Plant and process for the production of cement clinker
CN104807346A (en) * 2015-04-30 2015-07-29 云南创森环保科技有限公司 Powdery material cooling system

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1232030A (en) * 1967-10-31 1971-05-19
US3687431A (en) * 1970-12-18 1972-08-29 Aluminum Co Of America Preheating of dry aggregate for carbon electrodes
DE2256385B2 (en) * 1972-11-17 1981-04-16 Metallgesellschaft Ag, 6000 Frankfurt Process for the continuous heating of fine-grained solids
US4008042A (en) * 1974-08-16 1977-02-15 Coaltek Associates Coal heating temperature control
DE2457528A1 (en) * 1974-12-05 1976-06-10 Bergwerksverband Gmbh PROCEDURE TO REDUCE DUST DEVELOPMENT WHEN INTRODUCING PREHEATED COAL INTO COOKING FURNACE
US4030983A (en) * 1975-04-04 1977-06-21 Bergwerksverband Gmbh Method of restricting dust development when feeding coal into coke ovens
FR2378081A1 (en) * 1977-01-24 1978-08-18 Charbonnages De France INSTALLATION AND METHOD OF REGULATING THE PREHEATING OF COKEFYING COAL
DE2719189C2 (en) * 1977-04-29 1984-07-19 Carl Still Gmbh & Co Kg, 4350 Recklinghausen Method for operating a coal pre-drying or heating system in connection with a coking plant
DE2748423A1 (en) * 1977-10-28 1979-05-03 Bergwerksverband Gmbh Providing inert atmosphere in coal heating plant - using heat-carrier gas generated in coal heating unit

Also Published As

Publication number Publication date
EP0026707A1 (en) 1981-04-08
NO802837L (en) 1981-03-27
BR8006070A (en) 1981-04-07
CA1127401A (en) 1982-07-13
AU534099B2 (en) 1984-01-05
RO81931B (en) 1983-05-30
ES495305A0 (en) 1981-11-01
DE3065381D1 (en) 1983-11-24
US4321032A (en) 1982-03-23
IN153919B (en) 1984-09-01
ES8200715A1 (en) 1981-11-01
RO81931A (en) 1983-06-01
AU6267480A (en) 1981-04-09

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