Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B15/00—Fluidised-bed furnaces; Other furnaces using or treating finely-divided materials in dispersion
  • F27B15/02—Details, accessories, or equipment peculiar to furnaces of these types
  • F27B15/10—Arrangements of air or gas supply devices
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2/00—Lime, magnesia or dolomite
  • C04B2/10—Preheating, burning calcining or cooling
  • C04B2/106—Preheating, burning calcining or cooling in fluidised bed furnaces
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B7/00—Hydraulic cements
  • C04B7/36—Manufacture of hydraulic cements in general
  • C04B7/43—Heat treatment, e.g. precalcining, burning, melting; Cooling
  • C04B7/434—Preheating with addition of fuel, e.g. calcining
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B7/00—Hydraulic cements
  • C04B7/36—Manufacture of hydraulic cements in general
  • C04B7/43—Heat treatment, e.g. precalcining, burning, melting; Cooling
  • C04B7/44—Burning; Melting
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B15/00—Fluidised-bed furnaces; Other furnaces using or treating finely-divided materials in dispersion
  • F27B15/02—Details, accessories, or equipment peculiar to furnaces of these types
  • F27B15/14—Arrangements of heating devices
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P40/00—Technologies relating to the processing of minerals
  • Y02P40/10—Production of cement, e.g. improving or optimising the production methods; Cement grinding
  • Y02P40/121—Energy efficiency measures, e.g. improving or optimising the production methods
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P40/00—Technologies relating to the processing of minerals
  • Y02P40/40—Production or processing of lime, e.g. limestone regeneration of lime in pulp and sugar mills

Definitions

• the present invention relates to a plant for calcination of a mineral filler containing a carbonate to produce a hydraulic binder, of the type comprising at least one calciner, the installation successively comprising a preheater, at least one binder production calciner comprising a chamber combustion, and a cooler; the combustion chamber comprising:
• combustion means for maintaining in the chamber a temperature between 700 0 C and 900 0 C, the combustion means comprising means for introducing into the chamber an oxidizing gas from the cooler;
• hydraulic binder a pulverulent material composed of fine particles which, in contact with water, react to form a solidified block to develop strength properties.
• hydraulic binders are cements, lime, slags, pozzolans, ashes from thermal power stations.
• the above-mentioned plant is intended for the production of an artificial hydraulic binder designated by the term "kalsin”, as described in application EP-A-0 167 465.
• the binders of kalsin type are produced based on clay phases, and at least one carbonate, preferably a calcium carbonate with optionally a magnesium carbonate.
• the carbonate is activated by dehydroxylation and by calcium combinations, without formation of free lime.
• carbonate refers to a salt resulting from the combination of carbonic acid with a base. This salt comprises a carbonate anion and a metal cation, preferably alkaline or alkaline earth metal.
• cement clinker is meant the material leaving a rotary flame-burning furnace, said material having formed balls or granules by partial melting at high temperature, for example about 1500 0 C, and by chemical combinations of different oxides such as oxides of calcium, silicon, aluminum, and iron.
• the clinker thus obtained is, after grinding with appropriate additives, capable of producing a cement.
• a known clinker production plant is described in EP 0 754 924.
• An object of the invention is therefore to provide a calcination plant of the aforementioned type which has reduced pollutant emissions.
• the subject of the invention is an installation of the aforementioned type, characterized in that the chamber comprises means for forming a fluidized bed, and in that the means for introducing the treatment gas are supplied with at least one partially by at least one bypass line of a part of the combustion fumes, the bypass pipe from the smoke evacuation means.
• the invention may include one or more of the following features, taken singly or in any technically feasible combination:
• the smoke evacuation means comprise a pipe for extracting the combustion fumes coming from the combustion chamber, the bypass pipe being stitched on the extraction pipe;
• the extraction line is connected to the preheater; it comprises an additional clinker production calciner, separate from the hydraulic binder production calciner, the additional calciner comprising a flame combustion furnace and the flue gas discharge means comprise an additional flue gas extraction duct; flame-burning furnace, the bypass pipe being stitched onto the additional extraction pipe;
• the additional extraction line is connected to an additional preheater, the additional preheater opening into the additional calciner;
• the combustion means comprise, successively, between the means for forming the fluidized bed and the means for introducing a gas with a controlled content of carbon dioxide:
• the means for injecting into the chamber the oxidizing gas coming from the cooler -
• the cooler is fed at least partially by a secondary bypass line of a portion of the combustion fumes from the smoke evacuation means;
• the cooler comprises secondary means for forming a fluidized bed for cooling the calcined mineral filler. it comprises recirculation means connecting a downstream region of the combustion chamber located downstream of the means for introducing the process gas, at an upstream region of the chamber, located upstream of the combustion means;
• the means for sampling the calcined mineral filler open out between the means for introducing the treatment gas and the means for forming the fluidized bed;
• the combustion means comprise a secondary combustion chamber comprising:
• the secondary chamber being connected to the combustion chamber through an outlet duct opening between the means for introducing the inorganic filler and the additional means for introducing the treatment gas.
• the invention also relates to a process for calcining a mineral filler containing a carbonate to produce a hydraulic binder, of the type comprising at least one calcination phase, the process comprising successively a preheating phase of the mineral filler in a preheater at least one calcination phase of the preheated mineral filler in a combustion chamber, and a cooling phase of the calcined mineral filler in a cooler; the calcination phase comprising the steps of:
• combustion step comprising the introduction into the chamber of an oxidizing gas from a cooler; Introduction into the chamber of a treatment gas with a controlled content of carbon dioxide, to oppose the dissociation of the carbonate in the chamber; and
• the method comprising a phase of evacuation into the atmosphere of combustion fumes produced during the or each calcination phase; characterized in that the calcination step comprises a step of forming a fluidized bed in the chamber, and in that the step of introducing a process gas comprises at least partial derivation of a part of the fumes combustion exhausted during the flue gas evacuation phase and a supply of the chamber by said combustion fumes derived.
• FIG. 1 is a schematic diagram showing a first installation according to the invention
• Figure 2 is an enlarged view of an upstream portion of the installation of Figure 1;
• Figure 3 is an enlarged view of a downstream portion of the installation of Figure 1;
• FIG. 4 is a view similar to that of Figure 3 of a second installation according to the invention.
• FIG. 5 is a view similar to that of Figure 3 of a third installation according to the invention.
• FIG. 6 is a view similar to that of Figure 2 of a fourth installation according to the invention.
• the calcination plant 11 of a crude mineral charge represented in FIG. 1 comprises a kalsin production unit 13, provided with a fluidized bed combustion chamber, and in parallel, a clinker production unit 17, provided with a rotary kiln 19 flame.
• the installation 11 also comprises means 21 for evacuating the combustion flue gases into the atmosphere, comprising a pipe 23 for extracting combustion fumes generated in the fluidized bed chamber 15, and an additional pipe 25 for extracting fumes. generated in the flame rotary kiln 19.
• Each conduit 23, 25 is provided with a fan 23A, 25A, and a device 23B, 25B for adjusting the fan, for example a shutter or a variable speed fan to separately adjust the respective flow rates of gas flowing in the respective installations. 13 and 17.
• a fan 23A, 25A, and a device 23B, 25B for adjusting the fan for example a shutter or a variable speed fan to separately adjust the respective flow rates of gas flowing in the respective installations. 13 and 17.
• the terms “upstream” and “downstream” refer to the circulation of the mineral charge in the installation.
• the kalsin production unit 13 successively comprises, from upstream to downstream, a preheater 27, a calciner 29 comprising the fluidized bed combustion chamber 15, and a cooler 31.
• the preheater 27 comprises a plurality of preheating cyclones 33 cascaded, in order to bring the descending mineral filler to the calciner 29 into contact with the fumes extracted from the calciner 29 which go back to the evacuation means 21.
• three cyclones 33A , 33B 1 33C are cascaded.
• the preheater 27 comprises an upper input 35 for introducing the raw mineral filler, a lower outlet 37 for discharging the preheated feedstock into the calciner 29, a lower inlet 39 for introducing the fumes from the calciner 29, and a upper outlet 41 for evacuating the cooled fumes opening into the extraction pipe 23.
• Each cyclone 33 comprises a tangential inlet 43 for supplying gas and material, a lower outlet 45 for discharging material provided with a non-return valve and an upper outlet 47 for evacuating gas.
• the upper feed inlet 35 of the raw mineral feedstock is connected in the gas conduit opening to the tangential inlet 43A for feeding the upper cyclone 33A.
• the lower discharge outlet 37 of the preheated charge is formed by the lower outlet 45C of the lower cyclone 33C.
• the lower inlet 39 for introducing the fumes from the calciner opens into the tangential inlet 43C of the lower cyclone 33C.
• the upper outlet 41 for discharging the cooled fumes is formed by the upper outlet 47A of the upper cyclone 33A.
• the tangential inlet 43B of the intermediate cyclone 33B is connected firstly to the lower outlet 45A of the upper cyclone 33A and secondly to the upper outlet 47C of the lower cyclone 33C.
• the upper outlet 47B of the intermediate cyclone 33B is connected to the tangential inlet 43A of the upper cyclone 33A.
• the lower exit 45B of the intermediate cyclone 33B opens into the tangential inlet 43C of the lower cyclone 33C.
• the fluidized bed combustion chamber 15 extends substantially vertically. It comprises, from upstream to downstream, from bottom to top in FIG. 2, means 51 for forming a fluidized bed, inlet 53 for introducing the preheated mineral filler, means 55 for combustion, an inlet 57 introduction of a treatment gas with a controlled content of carbon dioxide, and means 59 for recirculating the calcined mineral filler.
• the chamber 15 is furthermore provided, between the means for forming the fluidized bed 51 and the introduction inlet 53 of the inorganic filler, with an adjustable lateral outlet 61 for sampling the calcined mineral filler.
• the fluidized bed forming means 51 comprises a compressor 63 connected on the one hand, to a gas source 65, and on the other hand, to a plurality of fluidization gas injection nozzles 67.
• the source 65 contains for example carbon dioxide, or a gas comprising a mixture of carbon dioxide and oxygen, for example air mixed with combustion fumes or gases from a reactor producing carbon dioxide.
• carbon such as for example the rotary kiln 19.
• the carbon dioxide content by volume of this gas is for example between 10% and 40%.
• the oxygen content by volume of this gas, if it contains, is for example between 3% and 21%.
• the nozzles 67 are arranged in the bottom of the combustion chamber 15. Each nozzle 67 is connected to the compressor 63 via a pipe 69 provided with an adjustment valve 71.
• the mineral charge introduction inlet 53 is connected to the exhaust outlet 37 of the preheater 27. It opens laterally into the combustion chamber 15.
• the combustion means allow the introduction into the chamber 15 of fuel, with or without combustion gas, by means of burners.
• the combustion means 55 comprise a fuel supply inlet 73 and a combustion gas injection inlet 75
• the fuel supply inlet 73 is disposed substantially at the same level as the mineral charge introduction inlet 53. It is offset laterally with respect to this input input 53.
• the inlet 73 is connected to a fuel storage, dosing and transport facility (not shown) which contains, for example, poor quality fuels.
• Puls quality fuel means, for example, waste or by-products such as petroleum coke, used tires, plastic residues, sawdust, used oils, sludge, animal meal , which have a low calorific value and are difficult to burn. Since these low quality fuels are generally available on the market at low cost, their use represents a significant economic interest.
• the combustion gas injection inlet 75 opens downstream of the fuel supply inlet 73, in the vicinity of this inlet 73.
• This inlet 75 is formed of a plurality of peripheral openings opening into the chamber 15. These openings are distributed along an upstream gas injection crown 77, surrounding the combustion chamber 15.
• This upstream ring 77 is directly connected to an upper exhaust outlet 79 for discharging smoke from the cooler 31.
• the oxidizing gas introduced by the injection ring 77 is relatively rich in oxygen.
• the oxygen content by volume of this gas is, for example, between 3% and 21%.
• this gas is relatively low in carbon dioxide.
• the carbon dioxide content by volume of this gas is, for example, between 0% and 5%.
• the region 81 located between the injection nozzles 67 and the combustion gas injection inlet 75 defines a dense fluidized bed region, in which the inorganic filler is confined.
• the region 83 downstream of the inlet 75 defines an expanded fluidized bed region.
• the height of the dense region 81 that is to say the distance that separates the injection nozzles 67 from the combustion gas supply inlet 75, is chosen during the design of the installation 11, in function the nature of the fuel that will be used in that installation. 11. More specifically, this height is increased in the case where low quality fuels are used and decreased if the fuels used are easy to burn, such as high calorific fuels such as oil, natural gas or certain coals.
• the entry 57 for introducing a controlled carbon dioxide content gas is formed by a plurality of peripheral openings opening into the chamber 15, distributed along a downstream ring 85 for introducing gas.
• the downstream ring 85 is disposed downstream of the upstream ring 77, above this ring 77 in FIG.
• the inlet inlet 57 is fed by first and second bypass lines 91 and 93 from the means 21 for evacuating combustion fumes.
• the first bypass pipe 91 is stitched on the pipe 23 for extracting the combustion fumes generated in the combustion chamber 15.
• the second bypass pipe 93 is stitched onto the additional pipe 25 for extracting the combustion fumes generated by the flame furnace 19.
• Each bypass line 91, 93 is provided with an instrumentation comprising, successively from the extraction pipe 21, respectively, a flow regulating shutter 95, a blowing fan 97, a flow meter 99, and a sensor 101 of FIG. measuring the carbon dioxide content by volume in line 91, 93.
• Each element contained in the instrumentation is electrically connected to a central unit 103 for regulating the carbon dioxide content in the controlled content gas which passes through the inlet 57.
• the controlled carbon dioxide gas is relatively rich in carbon dioxide.
• the carbon dioxide content by volume of this gas is for example between 20% and 40%.
• this gas is also relatively low in oxygen.
• the oxygen content by volume of this gas is for example between 0% and 5%.
• the recirculation means 59 successively comprise from upstream to downstream, from top to bottom in FIG. 2, a pipe 111 for discharging material and gas and a separation cyclone 113.
• the evacuation pipe 111 opens transversely to the upper end of the combustion chamber 15.
• the cyclone 113 comprises a tangential inlet 115 connected to the evacuation pipe 111, a lower material discharge outlet 117, and an upper gas evacuation outlet 119 forming the lower entry 39 of the flue gas introduction. preheater 27.
• the outlet 117 opens into a recirculation pipe 121 which opens laterally into the combustion chamber 15 between the gas injection nozzles 67 and the mineral feed introduction recess 53, in the vicinity of this inlet 53.
• the opening of the pipe 121 in the chamber 15 is preferably located on the same side as the inlet 53.
• the recirculation pipe 121 is provided with a nonreturn valve 121A.
• the material withdrawal outlet 61 opens into a material supply inlet 122 of the cooler 31. It is provided with a control valve 123 of the amount of mineral charge taken.
• the control valve 123 comprises, for example, a frustoconical circulation passage 125 and a conical movable piston 127 for closing off this passage 125.
• the shutter piston 127 is mounted at the end of a rod movable in translation between a closed position of the passage and a fully open position of the passage.
• the outlet of the valve 123 is provided with a non-return valve.
• the cooler 31 comprises a plurality of cascaded cooling cyclones 133 of the same structure as the preheater 27, and a finished product extraction screw 135.
• the tangential inlet 137A of the upper cooling cyclone 133A is connected to an outlet of the sampling valve 123.
• the upper outlet 139A of the upper cyclone 133A is connected to the upstream injection ring 77.
• the tangential inlet 137C of the lower cyclone 133C is fed by a fresh air introduction pipe 140 provided with an adjustable fresh air suction fan 141 and a flow meter 143 downstream of the fan 141 in the direction fresh air circulation.
• a stitch 145 is provided between the tangential inlet 137C and the extraction screw 135, under the introduction line 140, to recover mineral matter from the lower outlet 147B of the intermediate cyclone 133B which would not be driven by the current. fresh air from the air introduction line 140.
• the material discharge outlet 147C of the lower cyclone 133C also opens into the extraction screw 135.
• the extraction screw 135 is disposed in a cooling chamber 149 whose walls are cooled by circulation of water. This is a cooling of the material from the quilting 145 and the outlet
• the chamber 149 opens into a lower outlet outlet 151 of kalsin.
• the kalsin production unit 13 is devoid of grinding means.
• the clinker production unit is for example of the type described in application EP 0 754 924. It comprises, from upstream to downstream, a flour preheater 161, an additional calciner 163 of the flour preheated, provided with the rotary flame combustion furnace 19, a chiller 165 of the calcined flour forming the clinker, and a grinding device 167 of the cooled clinker.
• the unit 13 comprises a duct 169 for evacuating the combustion fumes generated in the rotary kiln 19 which extends between the calciner 163 and the preheater 161. Furthermore, the additional extraction duct 25 is connected to the preheater 161. The combustion fumes produced in furnace 19 go up through preheater 161 and are evacuated via line 25.
• the smoke evacuation means 21 comprise at least one filter 171 into which the extraction lines 23, 25, and a fan 173 for exhausting fumes into the atmosphere, connected to a discharge outlet for the dedusted gases, open.
• the method of producing kalsin in the plant 11 will now be described.
• the method comprises a step of preheating the mineral filler, a step of calcining the preheated mineral filler, and a step of cooling the calcined mineral filler.
• the raw mineral filler or "flour" is introduced into the preheater 27 through the inlet 35.
• the flour is obtained from a mixture, called "raw", of calcium carbonate, with or without magnesium carbonate, and clay or marl, containing oxides of silicon, aluminum and / or iron .
• the raw material is milled in known manner in grinders with vertical grinding wheels or in ball mills, to a fineness characterized by a mass quantity of particles smaller than 200 microns of the order of 98 %, and a mass quantity of particles smaller than 100 microns of the order of 80% to 90%.
• the raw mineral filler circulates successively up and down in the cyclones 33, countercurrently from the combustion fumes coming from the calciner 29 via the inlet 39.
• the mineral filler is thus preheated in the preheater 27 by the combustion fumes to a temperature substantially between 650 ° and 800 ° C. at the outlet 37.
• the preheated inorganic filler is introduced into the combustion chamber 15 through the material introduction inlet 53.
• the mineral filler forms a dense fluidized bed in the region 81.
• the concentration of material in the dense region 81 is substantially between 50 kg / Nm 3 and 200 kg / Nm 3 of gas considered under standard conditions of temperature and pressure (0 ° C. and 100000 Pascals).
• the speed of the gases in the region 81 is between 0.6 m / s and 0.8 m / s, considered under the actual conditions of temperature and pressure.
• the suspended material in the form of an upward flow is then supported by the gases from the gas supply inlet 75 and the gas introduction inlet 57.
• a fluidized bed expanded in the dilute phase in which the gas velocity is greater than 2 m / s and preferably between 3 m / s to 5 m / s, and the concentration of material is decreased compared to that of the dense phase in the dense region 81.
• the fuel is introduced into the region 81 via the feed inlet 73.
• the fuel is brought into intimate contact with the feedstock by stirring produced by the fluidization phenomenon produced by the means 51.
• the combustion of the fuel is initiated, thanks to the oxygen contained in the fluidification gas. This start of combustion consumes all the oxygen from the gas source 65, creating a carbon dioxide-rich gas atmosphere all around the mineral filler particles.
• the temperature is then between 700 ° C. and 900 ° C. in the combustion chamber 15. Calcium combinations occur between the oxides of silicon, aluminum and / or iron activated during the preheating step, and the Activated calcium carbonate without release of carbon dioxide.
• the controlled carbon dioxide content gas constituted by a portion of the combustion fumes generated in the calciner 29, and a portion of those generated in the calciner 163 of the clinker production unit 17 is introduced into the chamber 15 through the downstream ring 85.
• the central unit 103 regulates the flow rate of the injected gas according to the carbon dioxide contents measured by the sensors 101 to maintain the carbon dioxide content in the chamber 15 measured by a sensor 199 substantially between 25% and 40%.
• the recycling of a part of the combustion fumes coming from the calcination chamber 15 and the flame oven 19 avoids the introduction of additional carbon dioxide into the installation 11, which also contributes to reducing polluting emissions into the atmosphere.
• the gas introduced by the ring 85 has a carbon dioxide content adapted to not impair the combustion of the fuel in the expanded region 83, even if the fuel is of poor quality. It is therefore possible to use a fluidized bed chamber to carry out the calcination, even with a poor quality fuel.
• the distance between the rings 85 and 77 is chosen greater when the fuel used is of poor quality. Since carbon-carbon dioxide dissociation is related to heat input from fuel combustion, it is possible when low-grade fuels that burn slowly are used to have a higher reaction volume. important between the two rings 85 and 77, without risking a too sharp combustion causing a dissociation of the carbonates. This arrangement facilitates the use of poor quality fuels.
• the inorganic filler is then conveyed by the gases to the upper end of the chamber 15, then discharged through the pipe 111 and the cyclone 113. It is then reintroduced into the dense region 81 by the recycling line 121. The load carries out thus, on average, several calcination cycles in the combustion chamber 15.
• part of the calcined charge is taken through the valve 123 and flows by gravity into the cooling cyclones. 133 successive.
• the charge is cooled by the fresh air introduced by the pipe 140 and circulating against the current of the charge in the cooling cyclones 133.
• the charge thus cooled has a temperature between
• the finished product discharged through exit 151 is a hydraulic binder designated by the term kalsin.
• This finished product only requires a low grinding energy because it is in the form of a fluid powder, of which only a few particles can sometimes agglomerate. If necessary, the finished product is partially mixed with the clinker produced in the clinker production unit 17 in the proportions specified in EP 0 167 465 to constitute, after grinding, a hydraulic binder.
• a material bypass pipe 201 is stitched between the material outlet 37 of the preheater 29 and the inlet inlet 53 in the calcining chamber 15, to divert part of the preheated mineral filler. This pipe 201 opens into the recirculation pipe 121.
• the inlet 57 is connected only to the bypass line 93 of the flue gases produced in the rotary kiln 19 of the unit 17.
• the second installation 211 according to the invention is similar to the first installation 11.
• the cooler 31 is devoid of cascading cooling cyclones.
• the cooler 31 comprises upstream and downstream fluidized bed corridors 213 and 215 arranged in cascade.
• the upstream corridor 213 extends substantially horizontally between a material introduction inlet 217, to the left ⁇ in the drawing, and a material outlet outlet 219 opening into the downstream chamber 215. It comprises a plurality of nozzles gas injection 221 and a downstream discharge opening 223 of gas.
• the material introduction inlet 217 is connected on the one hand to a sampling device 225 stitched on the recycling cyclone 113, and on the other hand, at the outlet of the sampling valve 123.
• the injection nozzles 221 are distributed at the bottom of the corridor 213 between the inlet 217 and the outlet 219. They are able to produce a dense fluidized bed with the mineral filler received from the calciner 29, by means of air or a mixture of air and compressed carbon dioxide received from a compressor 226.
• the bottom of the upstream corridor 213 is slightly inclined to promote the flow of the load from the inlet 217 to the outlet 219.
• the corridor 213 is devoid of nozzles.
• the cooling air is injected through a plurality of orifices in the bottom of the corridor 213.
• the opening 223 of gas evacuation is provided at the upper downstream end of the corridor 213.
• the opening is connected to a tangential conduit 227 for introduction into an evacuation cyclone 229.
• the upper outlet 231 of the cyclone 229 supplies the upstream ring 77 of the inlet 75 with combustion gas via a fan 232A and a flow measurement sensor 232B. Furthermore, the lower material outlet 233 of the cyclone 229 opens into the outlet 219, through a non-return valve.
• the structure of the second corridor 215 is similar to that of the first corridor 213. However, unlike the first corridor 213, a heat exchanger 235 with tube bundle, fed by water, is disposed in the corridor 215 facing injection nozzles 221. Furthermore, the upper outlet of the discharge cyclone 239 of the second passageway 215 opens into the smoke evacuation means 21, upstream of the filter 171 and downstream of the pipes 23 and 25, via a 237A fan.
• the compressor 238 of the corridor 215 is preferably supplied with ambient air.
• the gases from the cyclones 229 and 239 are sucked by the fans 232A and 237A.
• the flow of gas flowing in the pipe 231 is measured by the device 232B, while its flow rate is controlled by the speed of rotation of the fan 232A or by means of adjustable registers in position.
• the flow rate of gas passing through cyclone 239 is controlled by the speed of fan 237A so as to obtain a slightly negative static pressure in line 219A connecting the outlet 219 of the first passageway 213 to the second passageway 215.
• a pressure measuring device is installed for this purpose in the conduit 219A. This arrangement in the conduit 219A prevents a rise of gas from the corridor 215 to the corridor 213 through the conduit 219A.
• the material extraction device 225 comprises a fluidization chamber 251, opening into the lower extension of the cyclone of recirculation 113, and a lateral discharge outlet 253 taken off by a secondary sampling valve 255.
• the fluidizing chamber 251 comprises in its bottom, a plurality of compressed air injection nozzles 257 from a compressor 259.
• the valve 255 has a similar structure to the sampling valve 123. It is disposed between the outlet 253 sampling material and the inlet 217 of the upstream lane 213. The output of the valve 255 is provided with a non-return valve.
• this installation 211 is moreover analogous to that of the installation 11 described with reference to FIG.
• the calcined mineral filler is cooled by the fluidification gas injected into the successive corridors 213, 215.
• the installation 311 shown in FIG. 5 differs from the first installation 11 in that the inlet 57 for introducing the controlled carbon dioxide content gas is connected only to the second bypass line 93 coming from the unit. 17 clinker production.
• the cooler 31 comprises a primary cooler 313A and a secondary cooler 313B disposed under the primary cooler 313A.
• the primary cooler 313A comprises two cascaded cooling cyclones 315A, 315B, as previously described.
• the outlet of the sampling valve 123 is connected to the tangential inlet 317A of the upper cyclone 315A of the primary cooler 313A. Furthermore, the first bypass line 91 is connected to the tangential inlet 317B of the lower cyclone 315B of the primary cooler 313A. This tangential inlet 317B is also connected to a primary product extraction screw 319A.
• the upper outlet 321 A of cyclone 315A opens into the upstream ring 77.
• the secondary cooler 313B has a similar structure to the cooler 31 of the installation 11. However, the tangential inlet 329A of the upper cyclone 331A of the secondary cooler 313B is connected to the lower outlet 333B of the lower cyclone 315B of the primary cooler 313A.
• the upper outlet 335A of the upper cyclone 331A of the secondary cooler 313B opens into the combustion chamber 15 via a secondary inlet 337 supplying oxidizing gas.
• the mineral charge exiting the lower cyclone 331 C of the secondary cooler 313B opens into the secondary product extraction screw 337B.
• the installation 11 is devoid of clinker production unit.
• the input 57 for introducing the process gas is only connected to the first bypass line 91.
• the installation 411 shown in FIG. 6 differs from that shown in FIG. 2 in that the combustion means 55 comprise a secondary combustion chamber 413 connected to the fluidized bed combustion chamber 15 via a pipe 415 exit, tilted down.
• the outlet pipe 415 opens into the combustion chamber 15 between the mineral charge feed inlet 53 and the carbon dioxide-controlled gas injection ring 85, above the dense region 81.
• chamber 15 is thus devoid of upstream ring 77 for introducing oxidizing gas, the inclined pipe 415 forming means 75 for injecting combustion gases into chamber 15.
• the secondary combustion chamber 413 comprises means
• the secondary combustion chamber 413 comprises two lines 419 and 421 for injecting combustion gas opening tangentially in the chamber 413, respectively in the upper part 418 and in a central portion 422 of the chamber 413. These conduits 419 and 421 are connected to the upper discharge outlet 79 of the cooler 31 of the cooler 31.
• the outlet 79 unlike the installation 11 shown in Figures 1 to 2, is not connected directly to the combustion chamber 15.
• the secondary combustion chamber 413 furthermore comprises a mineral feed inlet 423 emerging between the tangential lines for supplying combustion gases 419 and 421. This feed inlet
• the distribution device 425 is controlled to adjust the relative proportion of mineral filler introduced into the fluidized bed combustion chamber 15 and the secondary combustion chamber 413.
• the heat generated by the combustion of the fuel in this upper part 418 is then transmitted to the middle part 422 where the mineral filler introduced by the feed inlet 423 undergoes at least partial combustion, which continues in the outlet pipe 415.
• the relative proportion of inorganic filler introduced respectively into the combustion chamber 15 and the secondary combustion chamber 413 is adjusted according to the respective amount of fuel introduced into these chambers 15 and 413.
• the thermal energy consumed to implement the method according to the invention in the installation is reduced, given the low heat of reaction and the lower combustion temperatures compared to a clinker production unit. Furthermore, the use of kalsin as a hydraulic binder only requires a small amount of electrical grinding energy on the product delivered downstream of the cooler.
• the plant according to the invention also makes it possible to use a fluidized bed chamber for calcining the mineral filler, which allows the use of poor quality fuels.
• the facility may include a kalsin production unit connected to a conventional clinker production unit, to increase the overall capacity of the hydraulic binder production in the facility, while limiting the emissions of gaseous pollutants compared to a unit of unique clinker production of equivalent capacity.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Structural Engineering (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Dispersion Chemistry (AREA)
• Furnace Details (AREA)
• Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)
• Crucibles And Fluidized-Bed Furnaces (AREA)
• Treating Waste Gases (AREA)

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• 2004
  • 2004-10-19 FR FR0411103A patent/FR2876782B1/fr not_active Expired - Fee Related
• 2005
  • 2005-09-22 CN CN2005800403872A patent/CN101065337B/zh not_active Expired - Fee Related
  • 2005-09-22 EP EP05804195A patent/EP1807375A2/de not_active Withdrawn
  • 2005-09-22 US US11/577,573 patent/US7549859B2/en not_active Expired - Fee Related
  • 2005-09-22 BR BRPI0517082-6A patent/BRPI0517082A/pt not_active Application Discontinuation
  • 2005-09-22 WO PCT/FR2005/002360 patent/WO2006042923A2/fr active Application Filing

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