EP0369004B1 - Internal circulation type fluidized bed boiler and method of controlling same - Google Patents

Internal circulation type fluidized bed boiler and method of controlling same Download PDF

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Publication number
EP0369004B1
EP0369004B1 EP87904742A EP87904742A EP0369004B1 EP 0369004 B1 EP0369004 B1 EP 0369004B1 EP 87904742 A EP87904742 A EP 87904742A EP 87904742 A EP87904742 A EP 87904742A EP 0369004 B1 EP0369004 B1 EP 0369004B1
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EP
European Patent Office
Prior art keywords
fluidized bed
bed
partition wall
thermal energy
air
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 - Lifetime
Application number
EP87904742A
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German (de)
English (en)
French (fr)
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EP0369004A1 (en
EP0369004A4 (en
Inventor
Takahiro Ohshita
Tsutomu Higo
Shigeru Kosugi
Naoki Inumaru
Hajime Kawaguchi
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Ebara Corp
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Ebara Corp
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Priority to AT87904742T priority Critical patent/ATE85682T1/de
Publication of EP0369004A1 publication Critical patent/EP0369004A1/en
Publication of EP0369004A4 publication Critical patent/EP0369004A4/en
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B1/00—Methods of steam generation characterised by form of heating method
    • F22B1/02—Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers
    • 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
    • F23C10/005—Fluidised bed combustion apparatus comprising two or more beds
    • 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
    • F22B31/0084—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 with recirculation of separated solids or with cooling of the bed particles outside the combustion bed
    • F22B31/0092—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 with recirculation of separated solids or with cooling of the bed particles outside the combustion bed with a fluidized heat exchange bed and a fluidized combustion bed separated by a partition, the bed particles circulating around or through that partition
    • 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
    • F23C10/02—Fluidised bed combustion apparatus with means specially adapted for achieving or promoting a circulating movement of particles within the bed or for a recirculation of particles entrained from the bed
    • F23C10/04—Fluidised bed combustion apparatus with means specially adapted for achieving or promoting a circulating movement of particles within the bed or for a recirculation of particles entrained from the bed the particles being circulated to a section, e.g. a heat-exchange section or a return duct, at least partially shielded from the combustion zone, before being reintroduced into the combustion zone
    • F23C10/06—Fluidised bed combustion apparatus with means specially adapted for achieving or promoting a circulating movement of particles within the bed or for a recirculation of particles entrained from the bed the particles being circulated to a section, e.g. a heat-exchange section or a return duct, at least partially shielded from the combustion zone, before being reintroduced into the combustion zone the circulating movement being promoted by inducing differing degrees of fluidisation in different parts of the bed
    • 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
    • F23C10/02—Fluidised bed combustion apparatus with means specially adapted for achieving or promoting a circulating movement of particles within the bed or for a recirculation of particles entrained from the bed
    • F23C10/12—Fluidised bed combustion apparatus with means specially adapted for achieving or promoting a circulating movement of particles within the bed or for a recirculation of particles entrained from the bed the particles being circulated exclusively within the combustion zone
    • F23C10/14—Fluidised bed combustion apparatus with means specially adapted for achieving or promoting a circulating movement of particles within the bed or for a recirculation of particles entrained from the bed the particles being circulated exclusively within the combustion zone the circulating movement being promoted by inducing differing degrees of fluidisation in different parts of the bed
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
    • F23G5/00—Incineration of waste; Incinerator constructions; Details, accessories or control therefor
    • F23G5/30—Incineration of waste; Incinerator constructions; Details, accessories or control therefor having a fluidised bed

Definitions

  • the invention relates to a circulating fluidised bed boiler and a method of controlling the same .
  • the boiler and the method are useful for incinerating coal, anthracite, coal dressing sludge, petro coke, bark, bagasse, industrial waste, municipal waste and other combustibles.
  • a diffusion plate 2 is provided at a furnace bottom of an incinerator 1 for the purpose of causing fluidisation of a fluidized medium.
  • the diffusion plate 2 is inclined so that the wall side provided with a waste feeding device 3 is higher than the opposite side, the lower portion of the opposite side being coupled with an incombustible discharge opening 4.
  • Fluidizing air fed from a blower 8 is blown upwardly from the diffusion plate 2 through air chambers 5, 6 and 7 to fluidize the medium.
  • the mass flow of the fluidizing air blown up from each of the air chambers is arranged to be sufficient to produce a fluidized bed, the flow blown up from the chamber 7 being the largest and that from the chamber 5 being the smallest.
  • the mass flow is selected from the following ranges, namely, that blown up from the air chamber 7 being in the range of 4 - 20 Gmf, or preferably 6 - 12 Gmf, that from the air chamber 6 being in the range of 3 - 10 Gmf, or preferably 4 - 6 Gmf, and that from the chamber 5 being in the range of 1 - 4 Gmf, preferably 1 - 2.5 Gmf.
  • 1 Gmf is a value of the mass flow at which the fluidization is commenced.
  • the state of the fluidizing medium is changed from a static state, which is referred to as a static bed, to a dynamic state, which is referred to as a fluidized bed, with the above value as a threshold between the two states.
  • Fig. 1 shows three air chambers, the number is optional and may, for example, be two or more than four chambers, and the mass flow of the fluidizing air is arranged to be large for the chamber near the discharge opening 4 and small for the chamber remote from the discharge opening.
  • an inclined wall 9 is provided to serve as a deflecting wall for interrupting passage of the upward flowing fluidizing air so as to deflect the air towards the combustible feeding device 3.
  • an inclined surface 10 whose inclination is opposite to that of the wall 9 is provided to prevent the fluidized medium from becoming piled up thereon.
  • the inclination of the diffusion plate 2 is, in the case where the incombustibles are contained in the combustibles to be charged, preferably in the range of 5 - 15°; however, in the case where the amount of incombustibles is small, the inclination may be nil and the plate may be horizontal since the fluidized medium can be put into circulation by adjusting the flow rate of the air blown from the respective air chambers.
  • the surface of the wall 9 may be either flat, convex or concave.
  • a combustion gas exhaust 12 a feed conduit 13 for feeding liquid waste generated upon operating the incinerator, and a cooling water feeding conduit 14 etc. are provided.
  • the fluidizing air is fed thereinto by the blower 8 and the fluidizing air is injected in regulated amounts of mass flow decreasing in the order of the chambers 7, 6 and 5.
  • the fluidized medium moves violently up-and-down, just like boiling water, to produce a fluidizing state.
  • the fluidized medium at the portion near the side wall provided with the combustible feeding device 3 does not move violently up-and-down and forms a moving bed 15 which experiences weak fluidization.
  • the width of the moving bed is narrow at the upper portion thereof and is spread at the lower portion due to the difference in the mass flow of the air injected from the respective air chambers. That is, the trailing end of the moving bed extends above the air chamber 6 or 7 and, thus, the fluidized medium is blown upwardly by the large mass flow from these chambers so as to be displaced therefrom, whereby a part of the moving bed 15 above the air chamber 5 descends by gravity.
  • the fluidized medium is supplemented from the fluidized bed accompanying a circulating flow 16 towards the upper portion of the bed 15 and with the repetition of the above, as a whole, the circulating fluidized bed is formed.
  • the fluidized medium moved above the air chambers 6 and 7 is blown upwardly against the inclined wall 9 where it is deflected and whirled towards the side wall having the combustible feeding device, descending gradually after it reaches the upper portion of the moving bed 15, and is then blown up again to circulate after it reaches the trailing end.
  • the combustibles fed from the feeding device 3 to the top of the moving bed 15 in the incinerator 1 under the state just explained are entrained within the descending moving bed 15 and move downwards.
  • the incombustibles charged together with the combustibles firstly descend within the descending moving bed 15 and thence move in the lateral direction and, during such movement, the combustibles attached to or unitarily incorporated in the incombustibles (for example, the coatings on electric wires) are incinerated.
  • the incombustibles reaching the trailing end are delivered to the incombustible discharge opening 4 due to the lateral movement of the fluidizing medium and the inclination of the air diffusion plate 2, pass through a vertical passage 17 and an incombustible discharge conveyor 18, and are discharged outwardly after the fluidized medium is sorted by means of a vibrating sieve 19.
  • the sorted fluidized medium or fresh fluidized medium is fed to the incinerator 1 by a transporting means 20 such as an elevator.
  • a diffusion plate 22 for the fluidizing air is provided at the internal bottom portion of the incinerator.
  • the opposite edge portions of the air diffusion plate 22 are arranged to be lower than the central portion and the diffusion plate is formed to represent the configuration of a hill (a chevron shape) in section approximately symmetrical about the center line 42 of the incinerator and an incombustible discharge opening 24 is coupled to each of the opposite edge portions.
  • the fluidizing air fed from a blower 28 is injected upwardly from the air diffusion plate 22 through air chambers 25, 26 and 27.
  • the mass flow of the fluidizing air injected from each of the air chambers 25 and 27 at the opposite edge portions is large enough to form the fluidized bed but the mass flow injected from the central air chamber 26 is made smaller than that from the former.
  • the mass flow for the fluidizing air injected from the air chambers 25 and 27 is selected to be in the range of 4 - 20 Gmf, preferably in the range of 6 - 12 Gmf, while the mass flow for the fluidizing air injected from the air chamber 26 is selected to be in the range of 0.5 - 3 Gmf, preferably in the range of 1 - 2.5 Gmf.
  • the number of air chambers is optionally determined as three or more. In a case where the number is more than three, the mass flow of the fluidizing air is arranged to be small at the chambers near the central portion and large at the chambers near the opposite edge portions.
  • inclined walls 29 are provided as deflecting walls to interfere with and deflect the fluidizing air towards the center of the incinerator.
  • inclined surfaces 30 each having an inclination opposite to that of the walls 29 are provided so as to prevent the fluidized medium from piling up.
  • the inclination of the diffusion plate 22 is preferably in the order of 5 - 15° in the case where the combustibles are accompanied by incombustibles.
  • the surface of the inclined walls 29 may be either flat, convex or concave.
  • a combustible charge opening 34 communicating with an outlet 33 of a combustible feeding device 23 is provided in opposing relation to the central air chamber 26 and an exhaust gas discharge portion 32 is also provided.
  • the inclined wall 29 may be constructed as a wall body constituted by metallic conduits through which the fluidizing air is passed so as to be pre-heated.
  • the fluidizing air is fed thereinto by a blower 28 and it is injected at a large mass flow from the air chambers 25 and 27 and at a small mass flow from the air chamber 26.
  • the fluidized medium moves up-and-down violently in a manner similar to boiling water to form the fluidizing state; however in the case of Fig. 2, the fluidized medium above the air chamber 26 does not produce this violent up-and-down motion and forms a moving bed in a state of weak fluidization.
  • the width of this moving bed is narrow at the upper portion thereof and spreads out laterally at the trailing ends in opposite directions towards the portions of the fluidized beds, and a part of the moving bed reaching above the air chambers 25 and 27 is blown upwardly where the fluidized medium is subjected to injection of the fluidizing air at the large mass flow.
  • the fluidized medium moved above the air chambers 25 and 27 is blown upwardly against the inclined walls 29 where it is deflected and whirled towards the center of the incinerator in the upward direction; however, due to the sudden increase of the sectional area of the incinerator, it loses its upwardly moving velocity such as to move onto the top of the descending moving bed 35, gradually descends, and is blown up again for circulation upon reaching the trailing end of the moving bed.
  • a part of the fluidized medium circulates as circulating flows 36 within the fluidized bed.
  • heat decomposition of the combustibles is effected partially to generate a combustible gas.
  • the generated combustible gas is diffused in the horizontal directions as the fluidized medium descends and diffuses and is burnt within the fluidized bed, the exothermic energy derived from the burning of the gas is made effective to heat the fluidized medium.
  • combustibles having a relatively large size are dried, gasified or incinerated within the descending moving bed 35 during the gradual downward travel and they are almost incinerated to become a small size by the time they reach the trailing end of the moving bed so that they do not interfere with the formation of the fluidized bed.
  • the shredder or the Shredding step may be omitted so as to make the facility compact.
  • the combustibles charged into the descending moving bed 35 rapidly diffuse in the fluidized medium and, thus, the incinerating efficiency is increased.
  • the medium size incombustibles fed through the combustible feeding device 23 firstly move downwardly and laterally within the descending moving bed 35 and, during such movement, any combustibles (for example the coating on electric wires) unitarily attached to or incorporated in the incombustibles are incinerated.
  • the incombustibles that reach the trailing end are delivered to the incombustible discharge openings 24 due to the lateral movement of the fluidized medium and the inclination of the diffusion plate 22 and are discharged through vertical passages 37.
  • the incombustibles are delivered by a conveyor 38 to a sieve (not shown) and the fluidized medium is sorted.
  • the fluidized medium is composed of solid grains which usually have a size of 1 mm or so and the incinerator is operated at the fluidizing medium temperature of 600 - 800°C, the exhaust gas temperature being 750 - 950°C.
  • the exhaust gas is cooled to approximately 300°C by a gas cooling chamber or air pre-heater and discharged through a chimney stack after removal of minute particles, or after recovering thermal energy by means of a boiler provided downstream of the exhaust gas discharge opening for the purpose of utilizing the waste thermal energy, or after passing through U-shaped conduits of a water warmer inserted in the free board portion 21 or 41, etc. and recovering more of the thermal energy, or being cooled as the dust is removed.
  • thermal conducting conduits are arranged within the fluidized bed and the heat transfer is effected under high heat transfer efficiency by virtue of physical contact between the conduits and the burning fuels at the high temperature and the fluidized medium.
  • a part of the minute combustibles which are not yet burnt, as well as ash or fluidizing medium (a recycling solid) merges into a flow of combustion gas and is directed to a heat transferring portion provided independently of the combustor where incineration of the unburnt substances is continued, the solid after this heat transfer being returned to the combustor together with a part of the combustion gas, and the name of this kind of boiler being given on account of the kind of recycling noted above.
  • an energy recovering chamber is disposed adjacent a main fluidizing chamber.
  • the apparatus disclosed is utilized to feed a part of the fluidized medium over a vertical partition wall to the energy recovering chamber; however, the temperature of the portion of the medium fed towards the recovering chamber is not effectively raised because it is moved upwardly in the fluidizing chamber without circulation and mixing to any substantial extent with the medium in the high temperature zone of the fluidizing bed, and is then fed to the recovering chamber where its temperature is lowered.
  • such medium is returned to the main fluidizing bed, its temperature is not sufficiently raised due to the phenomenon described above.
  • US-A-3 921 590 relates to a fluidised bed incinerator using a first and a second fluidized bed separated by a vertical partition wall. Sufficient bed material is transferred between the two beds to raise or lower the operating temperature of the material of the first bed to a desired level, i. e. an amount of cooler bed material is forced out of the second bed over the partition into the first bed. Fluid in a heat exchanger may be used for power generation.
  • UK-A-1 604 314 relates to fluidized bed combustors using an inclined baffle structure defining a chamber with heat exchanging tubes and containing bed material which is not fluidized.
  • US-A-4 528 945 relates to a boiler using in a bed a substantially vertical partition plate.
  • First and second bed means supply gas to diffusors located at different levels. After the bed has reached its normal operating temperature, air is supplied by the second feed means through the plates to those parts of the bed through which heat exchange tubes extend. The rate of heat transfer to the tubes is varied by varying the rate at which fluidizing air is supplied to these parts of the bed.
  • a steam-pressure sensing device senses the pressure of steam in a steam drum and an output signal from this device is used to control the second feed means in such a manner that the rate of heat transfer to the tubes is varied to maintain the steam pressure approximately constant.
  • This boiler relies above the second feed means on upwardly moving fluidized material.
  • an inclined partition wall is provided on the inside of the incinerator wall and above the end portion of the diffusion plate in place of the inclined wall to form a primary incinerating chamber of the fluidized bed and provision for a thermal energy recovery chamber is also made between the back side of the inclined partition wall and the incinerator wall or between two inclined partition walls so that the recovery chamber communicates at the upper and lower portions thereof with the primary incinerating chamber of the fluidized bed, thermal conducting conduits adapted to pass heating medium (fluid) therethrough being inserted into the thermal energy recovery chamber and a diffuser for the thermal energy recovery chamber being provided at the lower part of the recovery chamber along the back side of the partition wall.
  • the heated fluidized medium introduced into the thermal energy recovery chamber beyond the upper portion of the inclined partition wall is subjected to the fluidizing gas blown from the diffuser and regulated in an amount of 0 - 3 Gmf or preferably 0 - 2 Gmf to form a static bed or a descending moving bed of the fluidized medium so that the thermal energy of the fluidized medium is recovered by the heating medium passing through the thermal conducting conduits.
  • the inventors found that, by the arrangement noted above, it is possible to easily control the temperature of the primary incinerating chamber of the fluidized bed in the incinerator above explained while effectively recovering the thermal energy by the thermal conducting conduits in the fluidized zone where the degree of abrasion of the thermal conducting conduits is small.
  • the inventors have further investigated and developed the circulating fluidized bed type incinerator provided with the thermal energy recovery chamber that accompanies the inclined partition wall and the method for recovering thermal energy and controlling the feeding rate of the fuel and found it possible to form an effective circulating fluidized bed using the fluidized medium heated in the primary chamber and to introduce a sufficient amount of the heated fluidized medium required in the thermal energy recovery chamber by arranging the inclination of the inclined partition wall to be 10 - 60° or preferably 25 - 45° relative to the horizon and the projection length of the inclined partition wall in the horizontal direction on the bottom of the incinerator to be 1/6 - 1/2 or preferably 1/4 - 1/2 of the horizontal length of the bottom of the incinerator.
  • the inventors found it possible not only to fully meet the demand from users utilizing the recovered thermal energy but also to limit the degree of temperature variation in the primary chamber within a small range by controlling the amount of thermal energy recovered from the thermal energy recovery chamber by regulation of the thermal calory of the heating medium passed through the thermal conducting conduits, for example by regulating the flow rate, pressure and temperature of the vapor or the temperature, etc. of the hot water, etc. at the same time regulating the amount of air blown from the diffuser for controlling the descending rate of the fluidizing medium in the thermal energy recovery chamber in response to variations in the demands from the users, for example those regarding the vapor pressure and temperature and the regulation of the amount of fuel supplied, such being determined in response to the demands from the users or based upon the temperature in the primary chamber.
  • Figs. 1 and 2 are sectional views explaining the conventional circulating type fluidized bed incinerator;
  • Fig. 3 is a schematic illustration explaining the principle of the present invention;
  • Fig. 4 is a sectional view of an internal recycling type fluidized bed boiler explaining in outline the construction according to the present invention;
  • Fig. 5 is a graph showing the relationship between the amount of air for fluidization (Gmf) at the portion below the inclined partition wall in the primary fluidized bed incinerating chamber and the amount of the fluidized medium recycled;
  • Fig. 6 is a graph indicating the relationship between the amount of diffusing air (Gmf) in the thermal energy recovery chamber and the descending rate of the downward moving bed in the thermal energy recovery chamber;
  • Fig. 1 and 2 are sectional views explaining the conventional circulating type fluidized bed incinerator;
  • Fig. 3 is a schematic illustration explaining the principle of the present invention;
  • Fig. 4 is a sectional view of an internal recycling type fluidized bed boiler explaining in outline the construction according to the
  • FIG. 7 is a graph indicating the relationship between the mass flow for fluidization (Gmf) and the overall thermal conducting coefficient in the conventional bubbling type boiler;
  • Fig. 8 is a graph indicating the relationship between the diffusion mass flow (Gmf) in the thermal energy recovery chamber and the overall thermal conducting coefficient in the internal recycling type fluidized bed boiler according to the present invention;
  • Fig. 9 is a graph showing the relationship between the mass flow for fluidization and the abrasion rate of the thermal conducting conduit;
  • Figs. 10 and 11 show variations in the fuel feeding amount, vapor pressure and the fluidized bed temperature relative to the lapse of time without and with regulation of the fluidizing mass flow for the thermal energy recovery chamber in response to stepwise change of the vapor flow rate;
  • FIG. 12 shows similar variations relative to the lapse of time in response to lumpwise change of the vapor flow rate
  • Figs. 13 and 14 are sectional drawings explaining other embodiments of the internal recycling type fluidized bed boiler according to the present invention
  • Fig. 15 is a sectional side view of an internal recycling type fluidized bed boiler explaining still another embodiment of the present invention which is particularly adapted for use as a small boiler
  • Fig. 16 is a section taken in a plan view on a line shown by the arrows A - A in the drawing of the embodiment shown in Fig. 15 which particularly illustrates the section in plan view of an internal recycling type fluidized bed boiler adapted for use in a circularly packaged boiler
  • Figs. 17 - 19 illustrate fluidizing patterns in a primary fluidized bed incinerating chamber with the relationship between the horizontal length L of the incinerator bottom and the projection length l of the inclined partition wall in the horizontal direction.
  • a diffusion plate 52 is provided at the bottom of an incinerator 51 for introducing fluidizing air fed by a blower 57 through a fluidizing air feeding conduit 53, the diffusion plate 52 being configured in the shape of a hill (chevron shape) approximately symmetrical about the center line of the incinerator so that the opposite end portions are lower than the center portion thereof.
  • the fluidizing air fed from the blower 57 is arranged to be injected upwardly from the air diffusion plate 52 through air chambers 54, 55 and 56 and the mass flow of the fluidizing air injected from the opposite end air chambers 54 and 56 is arranged to be sufficient to form the fluidized bed of the fluidized medium within the incinerator 51, while the mass flow of the fluidizing air injected from the center air chamber 55 is selected to be smaller than that from the former as explained before in connection with the examples of prior art.
  • Inclined partition walls 58 are provided above the opposite end air chambers 54 and 56 as a deflecting wall means designed to interfere with the upwardly directed passage of fluidizing air and to deflect the air towards the center of the incinerator, the circulating flows in the directions of the arrows shown being generated due to the presence of the inclined partition walls 58 and the difference in the mass flow of the injected fluidizing air.
  • thermal energy recovery chambers 59 are formed between the back side surfaces of the inclined partition walls 59 and side walls of the incinerator so that a part of the fluidized medium may be introduced during the operation into the thermal energy recovery chambers 59 beyond the upper ends of the inclined partition walls 58.
  • the inclined portion of the inclined partition wall is arranged to incline by 10 - 60°, or preferably 25 - 45° relative to the horizon and the projection length l thereof in the horizontal direction relative to the incinerator bottom is arranged to be 1/6 - 1/2, or preferably 1/4 - 1/2 of the horizontal length L of the incinerator bottom.
  • the angle of the inclination relative to the horizon and the projection length in the horizontal direction of the inclined partition wall are both factors which influence the fluidizing state of the fluidized medium in the primary fluidized bed incinerating chamber and the amount of grains introduced into the thermal energy recovery chambers.
  • the meaning of "L” and “l” and the flowing modes of the fluidized medium are shown in Fig. 17.
  • angle of inclination of the inclined portion is either smaller than 10° or greater than 60° relative to the horizon, a satisfactory circulating flow is not produced and the condition under which the fuel is incinerated deteriorates.
  • This angle is preferably in the range between 25° and 45° and it is particularly preferable if it is set at approximately 35°.
  • the projection length l of the inclined partition wall in the horizontal direction relative to the incinerator bottom is greater than 1/2 of the incinerator bottom length L as shown in Fig. 18, the amount of fluidized medium deflected from the inclined partition walls and caused to fall on the center of the incinerator becomes smaller thereby adversely affecting the formation of the moving bed at the incinerator center as well as the descending and diffusing mode of the fuel charged into the incinerator center.
  • a diffuser 62 for the thermal energy recovery chamber is provided for introducing gas such as air from a blower 60 through a feeding conduit 61.
  • an opening port 63 is provided at the portion in the thermal energy recovery chamber 59 adjacent to the place where the diffuser 62 is disposed, an opening port 63 is provided and the fluidizing medium introduced into the thermal energy recovery chamber 59 is caused to continuously or intermittently descend with a moving bed being formed, depending on the operating mode, and recycled into the incinerating portion through the opening port 63.
  • Fig. 4 shows an embodiment based on the principle of Fig. 3.
  • the descending amount of the fluidized medium in the thermal energy recovery chamber for recycling is regulated by the amount of diffusing air for the thermal energy recovery chamber and the amount of fluidizing air for the incinerating portion. That is the amount of fluidized medium (G1) introduced into the thermal energy recovery chamber is increased as shown in Fig. 5 if the amount of fluidizing air injected from the diffusion plate 52, particularly that from the end air chambers 54 and 56 which is intended to cause fluidization at the incinerating portion, is increased. Further, as shown in Fig.
  • the amount of fluidized medium descending in the thermal energy recovery chamber is changed approximately proportional to the change in the amount of diffusing air blown into the thermal energy recovery chamber when the change is in the range 0 - 1 Gmf and it becomes approximately constant if the amount of diffusing air for the thermal energy recovery chamber is increased beyond 1 Gmf.
  • This constant amount of fluidized medium is almost equivalent to the amount of fluidized medium (G1) introduced into the thermal energy recovery chamber and thus the amount of fluidized medium descending in the thermal energy recovery chamber becomes equivalent to a value corresponding to G1.
  • the descending amount of fluidized medium in the thermal energy recovery chamber 59 may be regulated.
  • the descent of the fluidized medium in the static bed when in the range of 0 - 1 Gmf is due to the difference in weight of the fluidized medium (the difference in height of the fluidized beds) as between the thermal energy recovery chamber and the primary fluidized bed incinerating chamber and, in the case where the mass flow is over 1 Gmf, the height of the moving bed portion becomes slightly higher or approximately equal to the other.
  • the recycling of the fluidized medium is assisted by a deflecting flow with a sufficient amount of fluidized medium brought about by the inclined partition wall.
  • the air flow moving upwardly along the inclined partition wall is given its direction by that wall and injected along the inclined partition wall from the fluidized bed, the fluidized medium being accompanied therewith.
  • the injected air flow is put in a state different from that in the fluidized bed and freed from the fluidized medium with which the fluidized bed is filled, and the sectional area of the air flowing passage is suddenly enlarged whereby the injected air flow is diffused and its speed is reduced to a few meters per second, becoming a gentle flow, and is exhausted upwardly.
  • the fluidized medium that accompanies the injected air flow loses its kinematic energy to fall due to gravity and the friction with the exhaust gas as the grain size of the fluidized medium is too large (approximately 1 mm) to be carried with the air flow.
  • a part of the fluidized medium gathered by the partition walls is injected along the deflecting partition wall with the direction imparted in a manner similar to that in the circulating type fluidized bed incinerator, while the other part, due to a sudden boiling phenomenon derived from the explosion of bubbles, is boiled upwardly like fire works just above the upper end of the inclined partition wall and falls all around the periphery. Accordingly, a part of the fluidized medium is introduced in a large amount towards the back side of the partition wall, i.e. the thermal energy recovery chamber.
  • the moving direction of the injected fluidized medium becomes closer to upright as the surface becomes higher above the upper end of the inclined partition wall. Therefore, the amount of fluidized medium introduced into the thermal energy recovery chamber becomes large in the case where the surface is slightly above the upper end of the inclined partition wall.
  • Fig. 5 is shown the relationship between the amount of fluidizing air in the portion below the inclined partition wall in the primary fluidized bed incinerating chamber and the amount of fluidized medium recycled through the thermal energy recovery chamber.
  • the amount of the fluidizing air and, if it is arranged to be more than 4 Gmf and preferably more than 6 Gmf, the value of G1/G0 is maintained over 1 and the required and sufficient amount of the recycling fluidized medium may be obtained even if the height of the fluidized bed is changed.
  • the mass flow of the air injected from the diffuser in the bottom of the thermal energy recovery chamber may be 0 - 3 Gmf, or preferably 0 - 2 Gmf
  • the mass flow of the fluidizing air injected from the diffusion plate disposed below the inclined partition wall to be 4 - 20 Gmf or preferably 6 - 12 Gmf, that is by always keeping the mass flow to be larger at the incinerating chamber side than at the thermal energy recovery chamber side, the amount of fluidized medium fed back to the primary fluidized bed incinerating chamber from the thermal energy recovery chamber may be adequately assured.
  • the moving bed in the thermal energy recovery chamber it is referred to in the academic sense as a static bed in the case where the mass flow is 0 - 1 Gmf and a fluidized bed in the case where the mass flow is over 1 Gmf and it is commonly known that a minimum mass flow of 2 Gmf is required for generating a stable fluidized bed.
  • the moving bed according to the present invention which is always descending and moving, the descending moving bed is satisfactorily formed until the mass flow is increased to the order of about 1.5 - 2 Gmf without causing the destruction of the moving bed by the bubbling phenomenon. It is assumed that the grains of the fluidized medium gradually descend and move under a vibrating mode whereby the fluidizing air is converted into small air bubbles uniformly flowing upward towards the upper portion of the moving bed.
  • thermal conducting conduits 65 through which a heat sink fluid such as vapor or water, etc. is passed, are arranged so that the thermal energy is recovered from the fluidized medium by effecting a heat transfer with the fluidized medium downwardly moving in the thermal energy recovery chamber.
  • the thermal conducting coefficient in the thermal energy recovering portion is greatly varied as shown in Fig. 8 in a case where the amount of the diffusing air in the thermal energy recovery chamber is changed in the range of 0 - 2 Gmf.
  • the fluidized medium is arranged in both the incinerating chamber and the thermal energy recovery chamber to be in a fluidized state (similar to water) so that the fluidized medium is caused to flow between the two chambers.
  • Fig. 8 The relationship between the overall thermal conducting coefficient and the mass flow for fluidization is shown in Fig. 8. As shown in Fig. 8, it changes almost linearly and, thus, the amount of thermal energy recovered and the temperature of the primary fluidized bed incinerating chamber may be controlled optionally. Further, such control may be easily effected simply by regulation of the amount of diffusing air in the thermal energy recovery chamber.
  • the abrasion rate of the thermal conducting conduits in the fluidized bed is proportionate to the cube power of the mass flow for fluidization and such relationship is shown in Fig. 9. Accordingly, the problem of abrasion regarding the thermal conducting conduits may be solved by arranging the amount of diffusing air blown into the moving bed in the thermal energy recovery chamber to be 0 - 3 Gmf or preferably 0 - 2 Gmf.
  • thermal energy recovery chamber 59 As a means for introducing the diffusing gas into the thermal energy recovery chamber 59, several means may be considered but it is generally disposed such as to be inclined along the back side of the inclined partition wall (the side facing the thermal energy recovery chamber) so as to effectively utilize the thermal energy recovery chamber.
  • the open ports for injecting the diffusing air are made smaller as their location becomes closer to the tip end of the diffuser (as the height of the bed becomes smaller) so that the diffusing air is prevented from being injected in large amounts at the tip end portion.
  • the respective sizes of the open ports are preferably determined so that an approximately uniform diffusing amount is injected over the full length of the diffuser 62 with the diffusing air amount being 2 Gmf. That is, when the above is met, it is possible to obtain the maximum amount of thermal energy recovered by all the thermal conducting surfaces in the thermal energy recovery chamber and the abrasion rate of the thermal conducting surfaces may be kept small over all the surfaces.
  • numeral 66 is a combustible charge inlet provided at the upper portion of the incinerator 51 and 67 is a steam drum for forming a circulating passage (not shown) with the thermal conducting conduits 65 in the thermal energy recovery chambers 59.
  • Numeral 69 represents incombustible discharge outlets coupled to the opposite end sides of the air diffusion plate 52 in the bottom of the incinerator 51 and 70 is a screw conveyor provided with screws 71 each having a helex opposite to the other.
  • the location of the combustible charge inlet is not limited to the upper portion of the boiler and it may be disposed at the side of the boiler as a spreader 66' for charging coal, etc. therethrough.
  • the combustibles F charged through the combustible charge inlet 66 or 66' are circulated and incinerated in the fluidized medium which is circulating under the influence of the circulating flow caused by the fluidizing air.
  • the fluidized medium at the upper center above the air chamber 55 is not accompanied by a violent up-and-down motion thereof and forms a descending moving bed which is in a weak fluidizing state.
  • the width of this moving bed is narrow at the upper portion thereof and the trailing ends thereof are extended in the opposite directions to reach the portions above the air chambers 54 and 56 at the opposite side ends, thus being subjected to the fluidizing air injected at a greater mass flow from both air chambers and blown upwardly.
  • each trailing end is displaced and, thus, the bed just above the air chamber 55 descends under gravity.
  • the fluidized medium piles up having been supplemented from the fluidizing bed, as explained later, and the fluidized medium above the air chamber 55 forms a gradually and continuously descending moving bed with the repetition of the above modes.
  • the fluidized medium moved above the air chambers 54 and 56 is blown upwardly and deflected and whirled by the inclined partition walls 58 towards the center of the incinerator 51 and falls on the top of the central moving bed and is circulated again as explained before, a part of the fluidizing medium being introduced into the thermal energy recovery chambers 59 beyond the upper portions of the inclined partition walls.
  • the angle of repose for the fluidized medium is formed at the upper portion of the thermal energy recovery chamber and the excess fluidized medium falls from the upper portion of the inclined partition wall to the primary fluidized bed incinerating chamber.
  • the fluidized medium introduced into the thermal energy recovery chamber 59 forms a gradually descending moving bed due to the gas injected from the diffuser 62 and it is returned to the primary fluidized bed incinerating chamber from the opening portion 63 after the thermal transfer is effected with the thermal conducting conduits.
  • the mass flow of the diffusing air introduced from the diffuser 62 in the thermal energy recovery chamber 59 is selected from values in the range of 0 - 3 Gmf or preferably 0 - 2 Gmf.
  • the thermal conducting coefficient varies from the minimum to the maximum below the value of 2 Gmf and the abrasion rate can be controlled, as shown in Fig. 9, within a small range.
  • the thermal energy recovery chamber is out of the strong corrosive zone of the primary fluidized bed incinerating chamber under the reducing atmospheres and, thus, the thermal conducting conduits 65 are subjected to less corrosion as compared to the conventional ones and the degree of abrasion of the thermal conducting conduits 65 is made quite small because the fluidizing rate in this portion is, as explained before, low.
  • the speed of air flow in the fluidizing air mass flow range 0 - 2 Gmf, it is quite low, for example such as 0 - 0.4 m/sec. (superficial velocity), at 800°C while it practically depends on the temperature and grain size of the fluidized medium.
  • the incineration residue is discharged together with a part of the fluidized medium by the screw conveyor 70 disposed at the bottom of the incinerator.
  • thermal conduction in the thermal energy recovery chamber 59 in addition to the thermal conduction that takes place due to the direct contact between the fluidized medium and the thermal conducting conduits 65, there is another form of thermal conduction that utilizes the rising gas moving upwardly as the conducting media, the gas moving up with irregular vibration as the fluidized medium moves.
  • there is substantially no boundary layer between the solid articles prohibiting the thermal conduction in contrast to the ordinary contact thermal conduction between gas and solid articles, and the fluidized medium is well agitated so that the thermal conduction within the grains of the fluidized medium may be neglegible, which fact may not be disregarded in a case where the medium is stationary; thus, quite substantial thermal conducting characteristics may be obtained. Accordingly, in the thermal energy recovery chamber according to the present invention, it is possible to obtain a large thermal conducting coefficient almost equal to 10 times that obtained in the conventional incinerating gas boiler.
  • the thermal conducting phenomenon that occurs between the fluidized medium and the thermal conducting surfaces largely depends on the strength or weakness of the fluidization and the amount of recycling fluidizing medium can be controlled by regulating the amount of gas introduced from the diffuser 62. Also, by arranging the thermal energy recovery chamber 59 with its moving bed to be independent from the primary incinerating chamber within the incinerator, it is possible to construct a compact thermal energy recovery apparatus in which the turning down ratio is large and the fluidized bed may be easily controlled.
  • the thermal conducting amount is instantaneously varied in the range between several times and several fractions by changing the amount of diffusing air in the thermal energy recovery chamber. Therefore, the variation in the thermal energy input into the fluidized bed based on the variation in the feeding amount of the combustibles depends on the incineration rate and causes a time lag; however, the amount of thermal energy recovery taking place in the thermal energy recovery chamber according to the present invention can be rapidly varied by varying the amount of diffusing air in the thermal energy recovery chamber and the response difference between the thermal input and the thermal recovery can be absorbed as a temporary change in the temperature of the fluidized medium due to the heat sensibility sinking capacity of the fluidized medium forming the fluidized bed. Accordingly, the thermal energy can be utilized without waste thereof and the regulation of the vaporizing amount having good response characteristic, which cannot be achieved with a conventional boiler such as one incinerating coal, can be obtained.
  • the locations of the incombustibles discharge openings 69 are, as shown for example in the drawing, preferably determined at positions near the opening ports 63 and the opposite side ends of the air diffusion plate in the incinerator 51; however, the location is not limited to that explained above.
  • the air diffusion plate 52 is illustrated as having the shape of a hill; however, if the amount of the fluidizing air injected from the air chambers 54 and 56 is arranged to be more than 4 Gmf, the circulating flow is formed in the primary fluidized bed incinerating chamber due to the effect of the inclined partition walls and, therefore, the air diffusion plate 52 may be made a horizontal one in the case where combustibles such as coal containing a few incombustibles are incinerated. Also, the incombustible discharge opening may be omitted.
  • the amount of thermal energy recovered from the thermal energy recovery chamber is controlled, in response to the demands of the user utilizing the recovered thermal energy, by regulating the amount of gas injected from the diffuser into the thermal energy recovery chamber.
  • the regulation of the temperature in the primary fluidized bed incinerating chamber is effected by controlling the fuel charging amount based on said temperature in the primary fluidized bed incinerating chamber or the vapor pressure and, in the boiler according to the present invention, the thermal conducting coefficient can be optionally adjusted and the variation of the amount of thermal energy recovered in the present invention is absorbed as variation in the sensible heat of the fluidized medium whereby the boiler can be controlled instantaneously to meet the demands of the user and can be operated under stable conditions.
  • a diffusing air regulating valve 93 is regulated in its opening direction by a regulator 92 for the valve 93 based on the temperature sensed by a thermo-sensor 91 on a vapor withdrawing conduit 90 so as to increase the amount of diffusing air injected so that the amount of thermal energy recovered is increased and the vapor temperature is raised to that demanded by the user.
  • the temperature of the primary fluidized bed incinerating chamber is controlled within a certain range by regulating the fuel feeding amount to the primary fluidized bed incinerating chamber and/or by regulating the air feeding amount to the air chambers 54, 55 and 56 based on the fluidized bed temperature sensed by a thermo-sensor 94.
  • Figs. 10 and 11 The response characteristics are shown in Figs. 10 and 11 wherein the vapor flow rate is changed by +30% stepwise from 70% to 100%.
  • Fig. 10 shows test results obtained when the air amount from the diffuser in the thermal energy recovery chamber was maintained constant while the vapor flow rate was varied by +30% stepwisely
  • Fig. 11 shows test results obtained in a case where the diffusing air amount was regulated in response to the +30% stepwise variation in the vapor flow rate.
  • the fluidized bed temperature and the vapor flow rate are constringed to predetermined values within a short time and the variation range is also made small in the case (Fig. 11) where the diffusing air amount is regulated according to the present invention in response to the variation in the vapor flow rate, as compared with the results for the conventional method shown in Fig. 10.
  • the variation range of the fluidized bed temperature was approximately ⁇ 12°C and that of the vapor pressure was approximately below ⁇ 0.3 kg/cm2 (0.029 MPa) in the case where the regulation was effected according to the present invention as shown in Fig. 11.
  • the responding characteristics are also shown in Fig. 12 when the vapor flow rate is varied lumpwisely by -60% wherein the diffusing air amount in the thermal energy recovery chamber is regulated in response to the above variation in accordance with the present invention.
  • the fluidized bed temperature is almost constant and the variation range of the vapor pressure is small.
  • FIG. 13 corresponds to the case wherein the present invention is applied to the incinerator shown in Fig. 1 in which a single circulating fluidized bed is present, the reference numerals being the same as those used in Fig. 3 with respect to the meaning and function thereof.
  • Fig. 14 shows an embodiment to be used when a large size boiler is required.
  • the embodiment shown in Fig. 14 is constructed by combining the two internal recycling type fluidized bed boilers shown in Fig. 4.
  • the operation is effected without difficulty by charging fuels from the charge inlet provided in the ceiling.
  • fuels such as coal having a grain size below several centimeters are incinerated
  • the internal recycling type fluidized bed boilers herein above explained are the sort that are preferably applied to boilers that are medium or large in size. As for small package boilers, it is desirable for them to be made more compact and, thus, an embodiment designed to such end is illustrated in Fig. 15.
  • the thermal conducting conduits 65 shown within the bed in Fig. 4 are oriented in an almost vertical direction and are extended to an exhaust gas heat conducting portion provided above the thermal energy recovery chamber so that this group of thermal conducting conduits is arranged to also serve as means for unitarily coupling a top water chamber 91 and a bottom water chamber 92.
  • the approximately vertical evaporating conduits in a plural number in a free board at the upper portion of the primary fluidized bed incinerating chamber and around the thermal energy recovery chamber, it is possible to utilize them as members for reinforcing the boiler body as well as to eliminate the need for auxiliary devices such as a forcible circulating pump and associated conduits, etc. because the fluid in the thermal conducting conduits including that in the conduits within the bed is automatically circulated.
  • a fluidized bed boiler and an exhaust gas boiler can be combined as a unitarily structure so that an internal recycling type fluidized bed boiler can be made economically available in a small size.
  • the exhaust gas generated after the incineration in the primary fluidized bed incinerating chamber is passed upwardly through the free board at the portion above the incinerating chamber and thence introduced into the group of thermal conducting conduits formed around the periphery from the upper portion of the group. It is then moved downwardly in a flow moving in a direction that is nearly normal relative to the thermal conducting conduits while effecting heat transfer.
  • the fuel charge inlet if it is arranged, for example as a type allowing charging from the top as illustrated, it is preferable to blow the secondary incinerating air towards the primary fluidized bed incinerating chamber.
  • an air curtain effect brought about the secondary air is expected to prevent fine fuel particles such as minute powdered coal from being scattered together with the incineration exhaust gas as well as to perform an effective agitation and mixing operation in the free board portion so that it may also contribute to effect sufficient contact between oxygen in the secondary air and the unburnt ash in the exhaust gas, thereby improving the incinerating efficiency and lowering the density of NO x and CO, etc.
  • Fig. 16 is a planar sectional view taken along the line shown by the arrow A - A in Fig. 15 and it particularly illustrates an example of a circular type boiler. In a case where it is a small size package boiler, it is not particularly necessary to make it a circular type as shown in Fig. 16, but manufacturing the arrangement of the thermal conducting conduits is made easy if it is made circular.

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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)
  • Sustainable Development (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Energy (AREA)
  • Fluidized-Bed Combustion And Resonant Combustion (AREA)
  • Devices And Processes Conducted In The Presence Of Fluids And Solid Particles (AREA)
  • Control Of Steam Boilers And Waste-Gas Boilers (AREA)
  • Steam Or Hot-Water Central Heating Systems (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
  • Heating, Cooling, Or Curing Plastics Or The Like In General (AREA)
  • Crucibles And Fluidized-Bed Furnaces (AREA)
EP87904742A 1987-07-20 1987-07-20 Internal circulation type fluidized bed boiler and method of controlling same Expired - Lifetime EP0369004B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT87904742T ATE85682T1 (de) 1987-07-20 1987-07-20 Wirbelbettofen mit innerer umwaelzung und verfahren zur steuerung desselben.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP1987/000530 WO1989000659A1 (en) 1987-07-20 1987-07-20 Internal circulation type fluidized bed boiler and method of controlling same

Publications (3)

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EP0369004A1 EP0369004A1 (en) 1990-05-23
EP0369004A4 EP0369004A4 (en) 1990-10-24
EP0369004B1 true EP0369004B1 (en) 1993-02-10

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EP87904742A Expired - Lifetime EP0369004B1 (en) 1987-07-20 1987-07-20 Internal circulation type fluidized bed boiler and method of controlling same

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EP (1) EP0369004B1 (ru)
KR (1) KR950007013B1 (ru)
AT (1) ATE85682T1 (ru)
AU (1) AU609731B2 (ru)
BR (1) BR8707989A (ru)
CA (1) CA1316413C (ru)
DE (1) DE3784174T2 (ru)
DK (1) DK166694B1 (ru)
FI (1) FI94170C (ru)
NO (1) NO168912C (ru)
RU (1) RU2059150C1 (ru)
WO (1) WO1989000659A1 (ru)

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JPH0629652B2 (ja) * 1987-07-13 1994-04-20 株式会社荏原製作所 流動床ボイラにおける燃焼制御装置
US5054436A (en) * 1990-06-12 1991-10-08 Foster Wheeler Energy Corporation Fluidized bed combustion system and process for operating same
DE4029065A1 (de) * 1990-09-13 1992-03-19 Babcock Werke Ag Wirbelschichtfeuerung mit einer stationaeren wirbelschicht
CA2116745C (en) * 1993-03-03 2007-05-15 Shuichi Nagato Pressurized internal circulating fluidized-bed boiler
US5401130A (en) * 1993-12-23 1995-03-28 Combustion Engineering, Inc. Internal circulation fluidized bed (ICFB) combustion system and method of operation thereof
EP0722067A3 (en) * 1995-01-12 1998-02-04 KABUSHIKI KAISHA KOBE SEIKO SHO also known as Kobe Steel Ltd. Heat recovery apparatus by fluidized bed
TW270970B (en) * 1995-04-26 1996-02-21 Ehara Seisakusho Kk Fluidized bed combustion device
CN101225960B (zh) * 2008-01-30 2010-06-09 重庆三峰卡万塔环境产业有限公司 逆推式垃圾焚烧炉炉膛
US8434430B2 (en) * 2009-09-30 2013-05-07 Babcock & Wilcox Power Generation Group, Inc. In-bed solids control valve
RU2552009C1 (ru) * 2013-12-30 2015-06-10 Евгений Михайлович Пузырёв Механизированная слоевая топка
RU2591070C2 (ru) * 2014-07-30 2016-07-10 Евгений Михайлович Пузырёв Твердотопливный котел с вихревой топкой

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3921590A (en) * 1972-10-20 1975-11-25 Douglas Allison Mitchell Fluidised bed incinerators

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1475992A (en) * 1974-04-11 1977-06-10 Fluidfire Dev Apparatus in which combustion takes place in a fludised bed
GB1604314A (en) * 1978-05-31 1981-12-09 Appa Thermal Exchanges Ltd Fluidised bed combusters
US4301771A (en) * 1980-07-02 1981-11-24 Dorr-Oliver Incorporated Fluidized bed heat exchanger with water cooled air distributor and dust hopper
US4419330A (en) * 1981-01-27 1983-12-06 Ebara Corporation Thermal reactor of fluidizing bed type
JPS57124608A (en) * 1981-01-27 1982-08-03 Ebara Corp Fluidized bed type heat-reactive furnace
CA1285375C (en) * 1986-01-21 1991-07-02 Takahiro Ohshita Thermal reactor

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3921590A (en) * 1972-10-20 1975-11-25 Douglas Allison Mitchell Fluidised bed incinerators

Also Published As

Publication number Publication date
FI896301A0 (fi) 1989-12-28
WO1989000659A1 (en) 1989-01-26
FI94170C (fi) 1995-07-25
KR950007013B1 (ko) 1995-06-26
RU2059150C1 (ru) 1996-04-27
NO168912B (no) 1992-01-06
DK166694B1 (da) 1993-06-28
AU609731B2 (en) 1991-05-09
AU7708887A (en) 1989-02-13
NO891168D0 (no) 1989-03-17
ATE85682T1 (de) 1993-02-15
KR890701950A (ko) 1989-12-22
DK128289A (da) 1989-05-11
DK128289D0 (da) 1989-03-16
EP0369004A1 (en) 1990-05-23
EP0369004A4 (en) 1990-10-24
FI94170B (fi) 1995-04-13
NO891168L (no) 1989-04-06
NO168912C (no) 1992-04-15
DE3784174D1 (de) 1993-03-25
BR8707989A (pt) 1990-05-22
DE3784174T2 (de) 1993-09-02
CA1316413C (en) 1993-04-20

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