EP0028458B1 - Chaudières à vapeur à lit fluidisé - Google Patents

Chaudières à vapeur à lit fluidisé Download PDF

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Publication number
EP0028458B1
EP0028458B1 EP80303472A EP80303472A EP0028458B1 EP 0028458 B1 EP0028458 B1 EP 0028458B1 EP 80303472 A EP80303472 A EP 80303472A EP 80303472 A EP80303472 A EP 80303472A EP 0028458 B1 EP0028458 B1 EP 0028458B1
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EP
European Patent Office
Prior art keywords
bed
shell
boiler
air
base plate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP80303472A
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German (de)
English (en)
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EP0028458A2 (fr
EP0028458A3 (en
Inventor
John Swithenbank
John Moore Miller
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
SANDFIRE Pty Ltd
Original Assignee
SANDFIRE Pty Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
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Priority claimed from GB8012013A external-priority patent/GB2073910A/en
Application filed by SANDFIRE Pty Ltd filed Critical SANDFIRE Pty Ltd
Priority to AT80303472T priority Critical patent/ATE12540T1/de
Publication of EP0028458A2 publication Critical patent/EP0028458A2/fr
Publication of EP0028458A3 publication Critical patent/EP0028458A3/en
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Expired legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B31/00—Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements of dispositions of combustion apparatus
    • F22B31/0007—Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements of dispositions of combustion apparatus with combustion in a fluidized bed
    • F22B31/0061—Constructional features of bed cooling
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B31/00—Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements of dispositions of combustion apparatus
    • F22B31/0007—Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements of dispositions of combustion apparatus with combustion in a fluidized bed
    • F22B31/0046—Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements of dispositions of combustion apparatus with combustion in a fluidized bed for boilers of the shell type, e.g. with furnace box
    • F22B31/0053—Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements of dispositions of combustion apparatus with combustion in a fluidized bed for boilers of the shell type, e.g. with furnace box with auxiliary water tubes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C10/00—Fluidised bed combustion apparatus
    • F23C10/18—Details; Accessories
    • F23C10/20—Inlets for fluidisation air, e.g. grids; Bottoms
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C10/00—Fluidised bed combustion apparatus
    • F23C10/18—Details; Accessories
    • F23C10/24—Devices for removal of material from the bed
    • F23C10/26—Devices for removal of material from the bed combined with devices for partial reintroduction of material into the bed, e.g. after separation of agglomerated parts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C10/00—Fluidised bed combustion apparatus
    • F23C10/18—Details; Accessories
    • F23C10/28—Control devices specially adapted for fluidised bed, combustion apparatus
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N1/00—Regulating fuel supply
    • F23N1/04—Regulating fuel supply conjointly with air supply and with draught
    • F23N1/042—Regulating fuel supply conjointly with air supply and with draught using electronic means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2225/00—Measuring
    • F23N2225/08—Measuring temperature
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2225/00—Measuring
    • F23N2225/08—Measuring temperature
    • F23N2225/16—Measuring temperature burner temperature
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2235/00—Valves, nozzles or pumps
    • F23N2235/02—Air or combustion gas valves or dampers
    • F23N2235/04—Air or combustion gas valves or dampers in stacks
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2235/00—Valves, nozzles or pumps
    • F23N2235/02—Air or combustion gas valves or dampers
    • F23N2235/06—Air or combustion gas valves or dampers at the air intake
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2239/00—Fuels
    • F23N2239/02—Solid fuels
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2241/00—Applications
    • F23N2241/10—Generating vapour

Definitions

  • the present invention relates to industrial steam-raising boilers having shells containing water and fire tubes and fluidised bed combustion chambers.
  • Fluidised boiler design tends to follow traditional practice wherein there is an air inlet plenum immediately below the support for the fuel. It has been proposed in U.S. Patent 1 443 496 to cool this support with water. However in traditional boilers, there is a tendency for the ash to fuse into a sticky slag which bonds itself onto the support forming a very effective heat transfer bond between the extreme heat of the fire and the support so tending to burn away the support. If there is a water leak into the red hot fire an explosion can occur. Thus water-cooling the support or base plate is not a feature which springs to the mind of a boiler designer. Moreover the water-cooled base shown in U.S. Patent 1 443 496 has to be a substantial casting to withstand temperature induced strains, expensive to make and instal in a boiler.
  • the present invention provides a fluidised-bed steam-raising boiler comprising a boiler shell for containing water to be heated, fire tubes within the boiler shell, a fluidised bed combustion chamber having a base plate, fuel introduction means into that chamber, and a combustion air plenum, characterised in that the chamber is located within but spaced from the shell's wall, that the plenum is mounted on the outside of the shell on the underside thereof, and that the plenum is connected to the chamber by air flow tubes sealingly penetrating the shell and the base plate with water in the shell circulating between the shell and the base plate outside those tubes.
  • the base plate does not form part of the envelope of the shell but can be designed as merely a part of the combustion chamber and that the shell can be designed purely as a boiler shell. An differential expansion between the base plate and the shell will be easily absorbed in the spacing provided between them.
  • Figures 1 and 2 show a horizontal shell boiler enclosed by an outer shell 11 within which a fluidised bed reactor chamber 12 is wholly contained.
  • the base plate 14 of the reactor chamber on the upper surface of which rests the bed, is spaced apart from the lower part of the shell 11 by stays 15 leaving the space between the two plates 14, open to the water jacket surrounding the reactor chamber 12.
  • Further stays 16 are used to locate the chamber 12 which is of considerable height so that the carrier or bed material of sand, alumina, or the like is not over-prone to elutriation (entrainment in the air stream).
  • a plurality of water tubes 17 cross through the chamber at an inclination to the horizontal and at various bearings to induce convective flows of water.
  • an exhaust gas turbine can be installed.
  • Banks of fire or smoke tubes 18 lead off from the combustion chamber to deliver heat from the combustion gases to water in the boiler.
  • the banks can form a single or a multiple pass as shown in the drawings.
  • the chamber is surrounded by water.
  • the base plate 14 is shaped so that any steam bubbles formed on its water side will float away and will not impair the heat transfer characteristics, and can be contoured for strength or other purposes.
  • a series of primary air tubes 20 extend between the two members to conduct primary air from a forced draught plenum 21 attached on the outside of the shell into the combustion chamber 12, some of these air pipes can serve as stays 15, which pipes 20a are shown in Figure 3.
  • Each air pipe has a bore 22 and receives a standpipe 23 which in Figure 3 is screwed directly into the air pipe and in Figure 4 which a non-structural standpipe 20b is shown, provided with a threaded collar which screws onto the air pipe.
  • the standpipes are of heat-resistant material and varying lengths of standpipes can be fitted to suit the fuel to be burnt and other relevant factors.
  • Each standpipe has its upper end blanked off and has holes in the sides.
  • the upper ends are blanked off by an umbrella plate 25 so that when the bed is slumped, without an air flow preventing the carrier entering the holes, the umbrella plate creates a clear space with the holes being in the clear space.
  • the size of the umbrella plate will, of course, depend on the angle of repose of the particular carrier material used so that the clear space is in fact large enough to leave the holes free.
  • Figure 5 shows another design of standpipe which does not require the top closure to be in the form of an umbrella plate.
  • This has a succession of air outlet holes 27 in an outer tube 28 which holes can be progressively blocked off by a valve device which comprises a tube 29 slidably located within the bore of the air pipe 21 associated with the standpipe. Upward movement of the inner tube 29 will block off the holes 27 which may be staggered to give an infinitely variable blocking off action.
  • the end of the tube 29 may be cut on an incline to give the same effect.
  • the lower end of the tube 29 is blanked off by a plate 30 above which there is a plurality of air inlet apertures 31.
  • a common activating means for the tubes 29 comprises a regulator plate 32 within the plenum which can be displaced up and down by suitable means sealingly entering the plenum.
  • This regulator plate can be perforated or otherwise adapted to balance out any unevenness of air pressure within the plenum or be connected adjustably to the various devices by flexible couplings 33 so as to allow each standpipe to take equal amounts of air.
  • the cooled base plate results in a number of advantages. Heat is delivered through the base plate itself from the fluidised bed so increasing the heat transfer surface area and owing to the cooling, the base plate is less liable to distort so that a relatively inexpensive material can be used.
  • the shell is also water cooled so that the problems associated with the seal between the plenum and the prior art base plate no longer arises, and this enables the use of a higher forced draught pressure. In fact a higher pressure throughout the air flow path can be used. A higher combustion pressure with the resultant greater oxygen content concentration, leads to more intense combustion and thus a smaller boiler.
  • the advantages are more pronounced in the so-called shallow bed versions of fluidised bed combustion.
  • a fuel inlet hatch 37 in the outer wall of the shell and the combustion chamber is fitted with a fuel feed device which limits blow-back of fuel on failure of combustion as well as limiting ingress of air additional to that required as secondary combustion air.
  • flow controlling standpipes also gives many advantages.
  • One advantage is the elimination of the need to have an umbrella plate on each standpipe which permits closer spacing of the standpipe for intensely active shallow bed burners.
  • the main advantage of regulating each standpipe instead of, or even as well as, using a common damper is that the air flow is more evenly shared between standpipes and regulating down the air flow does not change the balance of the air flow between standpipes.
  • the life of the base plate 14 will be extremely long not only because of its cooling but also because the carrier or bed material will after initially polishing the upper face of the member tend to plate out giving a wear and heat resistant surface.
  • a series of separators are provided in the exhaust circuit for separating out any solids elutriated out of the reactor chamber 12, which solids will be either ash or unburnt fuel dust.
  • the use of multiple separators such as cyclones would permit the various fractions such as the heavier fuel particles from the cyclone 39a, ash from the cyclone 39b and light fuel particles from the cyclone 39c, to be individually separated or at least for some fractions to be richer in unburnt fuel than others. At least the fuel rich fractions are fed back into a hopper 40 into which can also or alternatively be fed any light fuels likely to be elutriated such as straw, waste and sawdust.
  • the contents of the hopper are allowed to fall or are fed into a stream of air which can be derived from the forced draught fan (not shown) for feeding the plenum 21.
  • a tube or retort 41 leads into the active fire region preferably just above the quiescent layer and the stream of air with entrained fuel particles is directed into and through this tube which is of course hot, so that the particles are heated whilst they pass along the tube and are at least partially burnt therein.
  • This fuel return system can be incorporated into the reconditioning system described below. (shown in dotted outline in Figure 9).
  • the auxiliary fuel introduction means of Figure 6 is suitable for burning solid light fuels and Figure 7 shows another auxiliary fuel introduction means suitable for liquid fuels, especially those which may be difficult to burn because of a high flash point or a tendency to clog normal nozzles.
  • the fuel is introduced under pressure by means of a pump 42 with an outlet 43 leading into the quiescent layer of the fluidised bed that is below the level of the air outlets from the standpipes or sparge pipes.
  • the ash component of the quiescent layer soaks up the liquid fuel acting similarly to a wick in distributing the liquid fuel throughout the quiescent layer. On reaching the turbulent upper surface of the quiescent layer some of the wet ash is broken off and burnt in the active fire region. If any skin tends to form due to degradation of the liquid fuel, the skin will be broken away by the fuel pressure whilst the skin is still forming.
  • Figure 8 shows an alternative base plate structure.
  • a quiescent layer is not formed by means of stand or sparge pipes but the base plate proper 44 is a plan perforated plate which is thermally insulated from the active fire region 45 by a layer of coarse refractory bodies 46 resistant to elutriation.
  • bodies 46 Above this layer of bodies 46 there is the usual active fire region consisting of fuel and carrier.
  • the carrier can be charged into the chamber along with the heavier bodies and the graded layers can be formed by elutriation by a high pressure air stream.
  • the heavier bodies can be introduced first and then the carrier added with or without an air current.
  • the gaps between the coarser heavy bodies must be sufficiently small for the carrier to be unable to seep down through the gaps and through the perforations in the base plate proper. This can be done by judicious grading.
  • the base plate 44 can be spaced from the shell 11 by the air pipes 20 which would be welded to the shell and the base plate 44.
  • a bed reconditioning system is shown in Figure 9 to include a fuel inlet 60 to the reaction chamber 12.
  • the bed material 54 is removed through the drop tube 62 into a crushing unit 64 where the final particle size of the material can be reduced to a predetermined value.
  • the crushed material is then conveyed by a conduit 66 to be drawn off and entrained in an air stream by a venturi 68 which is fed with air from the forced draught fan in the direction of the arrow 70.
  • the reconditioned carrier material is fed back through the fuel inlet 60 to the reaction chamber 12.
  • partially burnt coal is returned to the bed and burnt to ash which is elutriated, and ground inert, incombustible material is introduced to the bed 54, which further reduces the necessity to top the bed up with fresh sand.
  • This embodiment permits substantially continuous operation of the fluidised bed burner and ensures that substantially all of the ash will be collected in the cyclones in the exhaust of the system.
  • the plenum 110 of a vertical fluidised bed boiler is fed with air under pressure in the direction of arrow 112.
  • the air rises through the base plate 114, on which rests a fluidised bed 113.
  • the heat generated from the fluidised bed flows upwardly through the reaction chamber which rises high enough to constitute a vertical flue, as a first pass.
  • the side walls 116 of the reaction chamber 115 are therefore heated by direct contact.
  • the heated gas then flows through a series 118 of smoke tubes which constitute a second pass, and then into a smoke box 120, from which the hot gases pass upwardly through a series 122 of smoke tubes constituting a third pass, terminating in a manifold 124, which is connected to suitable cyclones and chimneys (not shown).
  • a series of thermic siphon tubes 126 is provided, leading from the jacket 128, through the bed 113 and the reaction chamber 115 in order to produce steam. This steam rises and is then allowed to enter the steam space 130 above the level 132a of water above the flue 115. Baffles 132 are provided to avoid instability of the steam space 130.
  • the working pressure inside the steam space in the boiler shown is 860 KPa.
  • Coal or other fuel is introduced through the inlet orifice 134 and water enters through inlet 136.
  • An access door 138 is provided as well as a manhole ring 140.
  • a series of stays 142 serve to ensure constructional strength and the smoke pipe 118 and 122 also serve as constructional units.
  • a microprocessor may be used which constantly monitors the various parameters and all of some mechanical factors.
  • This microprocessor may be used with a number of boilers in conjunction with a modulator/de-modulator (MODEM) unit, which allows the microprocessor to receive and send messages along telephone wires to a central computer and/or to individual computers.
  • MODEM modulator/de-modulator
  • the central control can send warning signals to customers' boilers in advance of catastrophe or damage or malfunction, thereby providing a preventative maintenance feature.
  • a heater 210 is formed with an air distributor and plenum chamber 211 having an air inlet controlled by a damper 212.
  • the inlet leads from the forced draught fan (not shown).
  • Above the chamber 211 is a space occupied by the fluidised bed 213 of conventional design with its associated free-board 214.
  • the steam space is indicated by the reference numeral 215.
  • the heater 210 is fitted with four transducers. There are two thermocouples 217 and 218 in the bed 213 serving as temperature transducers. There are two pressure transducers 219 and 220 serving to sense the steam pressure and free- board pressure respectively.
  • the heater 210 is also fitted with a bed preheating unit 221 of any conventional construction which is controlled by an ignition control unit 222 which in turn is controlled by a start up control unit 223. Once activated the unit 223 is controlled by a signal from the thermocouple 217. At a predetermined bed temperature, the unit 223 causes the ignition control unit 222 to switch off the preheating unit 221. At another and lower temperature the unit 223 is once more activated and causes the unit 222 to operate once more.
  • thermocouple 218 signals a temperature controller 224 to control the fuel feed in a manner described later on.
  • the controller 224 functions through the unit 223 and as long as the unit 223 is activated, signals from the unit 224 are blocked and only signals from the unit 223 pass along the line 225 to a speed controller 226 which regulates the coal feed to the bed 213 of a coal feeder (not shown) so that only the quantity of coal required at start-up is fed to the bed 213.
  • the speed controller 226 is arranged to be operative over one or more ranges each from zero to a predetermined maximum. This is done by means of a three step controller 227 which enforces a maximum speed setting on the controller 226 in response to signals from the transducer 219. At a predetermined maximum pressure the coal feed is stopped. At a predetermined high pressure the lowest speed setting becomes operative and at two lower pressures, high speed settings become operative.
  • the three step controller 227 operates the damper 216 in a similar manner among one or more positions. At the maximum pressure in the freeboard the damper 216 is at its smallest opening and at two lower pressures it is at an intermediate and at its fullest opening. The damper 216 should never be closed.
  • the setting of the damper 216 affects the pressure in the freeboard 214 so that the transducer 220 senses any changes in pressure as the aperture of the damper 216 is changed.
  • the transducer 220 then signals a three term proportional controller 228 which controls the damper 212 causing the fluidising and combustion air to increase or decrease thus balancing the above bed pressure to a predetermined positive or negative pressure level.
  • This change in combustion air also increases and decreases the heat transfer surfaces covered by the fluid bed, i.e. increase in fluidising and combustion air gives an increase in heat transfer surface.
  • a decrease in fluidising and combustion air gives a decrease in heat transfer surface.
  • damper 216 in relationship with damper 212 and the correct delivery of coal to the combustion system must be related correctly with the combustion air, this being done by the three step controller 227.
  • the response time of the controller 228 and the damper 212 is shorter than the response time of the damper 216 to prevent pressurization of the space 214.
  • the unit 223 when the unit 223 is activated it overrides the control by the transducer 214 to enforce the setting of the damper 212 to that required at start up. As soon as the unit 223 is deactivated, the transducer 214 takes over.
  • controller 226 will have one or more maximum speed settings:
  • the damper 216 will also have four settings:
  • controller 228 would place the damper 12 into four settings resulting from a pneumatic connection derived from the above bed combustion chamber gas pressure:
  • the average bed temperature should be about 950°C and the maximum allowable about 1000°C.
  • the start up control unit 23 should become deactivated at A°C and come into operation again if the bed temperature drops to B°C, which is a temperature below that of A°C.
  • the temperature controller 224 will then send out signals over a range of A°C to 1000°C. At the latter temperature it would order the speed controller 226 to stop the coal feed while at A°C it would order the controller 226 to feed coal at the maximum rate permissible in terms of the setting allowed by the controller 227.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Solid-Fuel Combustion (AREA)

Claims (11)

1. Chaudière de production de vapeur à lit fluidisé comprenant une enceinte (11) destinée à contenir l'eau à chauffer, des tubes à feu (18) dans l'enceinte de la chaudière, une chambre de combustion (12) à lit fluidisé comprenant une plaque de base (14), des moyens (37) d'introduction du combustible dans la chambre, et une chambre d'admission d'air de combustion (21), caractérisée en ce que la chambre de combustion est située à l'intérieur mais séparée de la paroi de l'enceinte, en ce que la chambre d'admission est montée sur le côté externe de l'enceinte et sur son côté inférieur, et en ce que la chambre d'admission est reliée à la chambre de combustion par des tubes à air (20) qui pénètrant de façon étanche dans l'enceinte et dans la plaque de base, l'eau se trouvant dans l'enceinte circulant entre l'enceinte et la plaque de base à l'extérieur de ces tubes.
2. Chaudière selon la revendication 1, dans laquelle la plaque de base comprend des colonnes montantes d'air de combustion (23) formant la continuation des tubes à air au-dessus de la plaque de base, caractérisée en ce qu'au moins une partie des colonnes montantes comprennent ou sont associées à des dispositifs de commande de courant d'air, chaque dispositif étant individuel à une colonne montante et certains des dispositifs au moins comprenant un moyen d'actionnement commum (32).
3. Chaudière selon la revendication 1 ou 2, comprenant un moyen d'introduction de combustible auxiliaire (41) destiné à introduire des combustibles qui, du fait de leur légèreté ou de leurs dimensions, auraient tendance à être rapidement séparés par élutriation par le courant d'air de combustion, caractérisée en ce que ces moyens comprennent un tuyau s'étendant dans le lit de feu, dans sa région active.
4. Chaudière selon la revendication 3, caractérisé par des moyens (39) dans le circuit à gaz de la chaudière pour séparer au moins partiellement les uns des autres de la poussière de combustible élutriée et non brûlée, des matériaux combustibles légers provenant de déchets tels que de la paille et de la sciure, et de la cendre élutriée, et pour renvoyer les déchets combustibles et la poussière de combustible non brûlée aux moyens d'introduction de combustible auxiliaire et de ce fait dans la chambre.
5. Chaudière selon l'une quelconque des revendications précédentes, caractérisée par des moyens (62) pour retirer au moins une partie du matériau du lit, un broyeur (64) pur réduire la dimension des particules du matériau retiré autre que le matériau porteur jusqu'à approximativement celle du matériau porteur et des moyens (66) pour renvoyer le matériau broyé dans le lit.
6. Chaudière selon la revendication 4 ou 5, caractérisée en ce .que les moyens pour renvoyer le matériau comprennent un dispositif à venturi (68) pour entraîner le matériau retourné dans un courant d'air.
7. Chaudière selon l'une quelconque des revendications précédentes, comportant des moyens d'introduction de combustible auxiliaire (43) pour des combustibles liquides, caractérisée en ce que lesdits moyens d'introduction sont aménagés de manière à injecter du combustible sous pression dans une zone tranquille du lit.
8. Chaudière selon l'une quelconque des revendications précédentes sauf la revendication 2 et les revendications qui en dépendent, caractérisée en ce que la plaque de base est une plaque plate sans colonnes montantes, comportant à sa partie supérieur une couche (46) de corps réfractaires grossiers et résistant à l'élutriation, séparant la plaque de la région du feu actif.
9. Chaudière selon l'une quelconque des revendications précédentes, sous la commande d'un appareil de commande, caractérisée en ce que des détecteurs (219 et 217) sont au moins prévus pour détecter deux paramètres, le premier paramètre étant la pression de la vapeur dégagée ou la température de l'eau chauffée et le second paramètre étant la température du lit, avec des moyens (227) permettant d'appliquer le premier paramètre par étapes pour limiter la plage maximale à l'intérieur de laquelle le combustible peut être alimenté, et le second paramètre étant appliqué pour réguler l'alimentation dans cette plage.
10. Chaudière selon la revendication 9, dans laquelle l'appareil de commande est en outre caractérisée par des moyens (216) pour réduire le flux de gaz d'échappement en réponse aux niveaux de premier paramètre, un détecteur (220) détectant la pression des gaz du franc-bord pour un nombre choisi de niveaux étagés correspondant aux niveaux du premier paramètre et des moyens (212) pour réguler l'entrée de gaz ou d'air fluidisant en réponse aux niveaux de la pression des gaz du franc-bord.
11. Chaudière selon la revendication 9 ou 10, dans laquelle l'appareil de commande est caractérisé par un circuit de commande de démarrage (223) qui inhibe l'appareil de commande jusqu'à ce qu'une température prédéterminée du lit soit atteinte.
EP80303472A 1979-10-03 1980-10-02 Chaudières à vapeur à lit fluidisé Expired EP0028458B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT80303472T ATE12540T1 (de) 1979-10-03 1980-10-02 Dampferzeuger mit wirbelschicht-brennkammer.

Applications Claiming Priority (13)

Application Number Priority Date Filing Date Title
GB7934241 1979-10-03
GB7934241 1979-10-03
ZA801137 1980-02-28
ZA801307 1980-03-06
ZA801307 1980-03-06
GB8012013A GB2073910A (en) 1980-04-11 1980-04-11 Controls for fluidised bed burners
GB8012013 1980-04-11
GB8014964 1980-05-06
GB8014964 1980-05-06
GB8018852 1980-06-10
GB8018852 1980-06-10
ZA804876 1980-08-11
ZA804876 1980-08-11

Publications (3)

Publication Number Publication Date
EP0028458A2 EP0028458A2 (fr) 1981-05-13
EP0028458A3 EP0028458A3 (en) 1982-01-20
EP0028458B1 true EP0028458B1 (fr) 1985-04-03

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP80303472A Expired EP0028458B1 (fr) 1979-10-03 1980-10-02 Chaudières à vapeur à lit fluidisé

Country Status (1)

Country Link
EP (1) EP0028458B1 (fr)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3407132A1 (de) * 1984-02-28 1985-09-05 Buderus Ag, 6330 Wetzlar Regelung einer wirbelschichtfeuerung in einem heizungskessel
FR2591722B1 (fr) * 1985-12-18 1988-02-19 Charbonnages De France Generateur thermique a lit fluidise a moyens ameliores d'evacuation des cendres et de recuperation de chaleur
DE8916174U1 (de) * 1989-03-30 1994-10-20 Saarbergwerke Ag Wirbelbettfeuerungsanlage
EP2308193B1 (fr) 2008-07-25 2013-07-31 Alstom Technology Ltd Disposition de buse de fluidisation de combustible
US8714094B2 (en) * 2008-07-25 2014-05-06 Alstom Technology Ltd Fuel fluidizing nozzle assembly
GR1008000B (el) * 2012-08-21 2013-10-02 Tambov State Technical University, Λεβητας καυσης στερεου καυσιμου σε λεπτη διασπορα σε ρευστοποιημενη κλινη
FI126745B (fi) 2012-11-13 2017-04-28 Valmet Technologies Oy Leijukattilan ilmasuutinjärjestely, leijukattilan arinapalkki, leijukattilan arina ja leijukattila sekä menetelmä karkean materiaalin poistamiseksi leijukattilasta

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BE398976A (fr) *
US1443496A (en) * 1921-04-15 1923-01-30 Harry F Morris Furnace grate
GB1292442A (en) * 1968-10-18 1972-10-11 Laporte Industries Ltd Improvements in and relating to fluidised bed reactors
US3972180A (en) * 1971-09-21 1976-08-03 Chicago Bridge & Iron Company High pressure reactor with turbo expander
GB1433482A (en) * 1972-05-26 1976-04-28 Plessey Co Ltd Fluid bed apparatus with water cooled baffle
US3863606A (en) * 1973-07-25 1975-02-04 Us Environment Vapor generating system utilizing fluidized beds
GB1426579A (en) * 1973-09-21 1976-03-03 Coal Industry Patents Ltd Boilers
DE2356059A1 (de) * 1973-11-09 1975-05-15 Rheinstahl Ag Duese fuer einen wirbelschichtofen
US3907674A (en) * 1974-04-24 1975-09-23 Dorr Oliver Inc Fluid bed incineration of wastes containing alkali metal chlorides
US4072130A (en) * 1976-12-01 1978-02-07 The Ducon Company, Inc. Apparatus and method for generating steam
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DE2861817D1 (en) * 1977-09-23 1982-07-01 Exxon Research Engineering Co Method and apparatus for burning a solid, semi-solid and/or fluid fuel in a fluidized bed

Also Published As

Publication number Publication date
EP0028458A2 (fr) 1981-05-13
EP0028458A3 (en) 1982-01-20

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