EP0931981B1 - Apparatus and method for postcombustion of heavy ash with high contents of unburnt matter - Google Patents

Apparatus and method for postcombustion of heavy ash with high contents of unburnt matter Download PDF

Info

Publication number
EP0931981B1
EP0931981B1 EP99200062A EP99200062A EP0931981B1 EP 0931981 B1 EP0931981 B1 EP 0931981B1 EP 99200062 A EP99200062 A EP 99200062A EP 99200062 A EP99200062 A EP 99200062A EP 0931981 B1 EP0931981 B1 EP 0931981B1
Authority
EP
European Patent Office
Prior art keywords
ash
belt
air
postcombustion
zone
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
EP99200062A
Other languages
German (de)
French (fr)
Other versions
EP0931981A2 (en
EP0931981A3 (en
Inventor
Mario Magaldi
Alberto Carrea
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.)
Magaldi Ricerche e Brevetti SRL
Original Assignee
Magaldi Ricerche e Brevetti SRL
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
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=11378571&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0931981(B1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Magaldi Ricerche e Brevetti SRL filed Critical Magaldi Ricerche e Brevetti SRL
Publication of EP0931981A2 publication Critical patent/EP0931981A2/en
Publication of EP0931981A3 publication Critical patent/EP0931981A3/en
Application granted granted Critical
Publication of EP0931981B1 publication Critical patent/EP0931981B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23JREMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J1/00Removing ash, clinker, or slag from combustion chambers
    • F23J1/02Apparatus for removing ash, clinker, or slag from ash-pits, e.g. by employing trucks or conveyors, by employing suction devices
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23BMETHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL
    • F23B5/00Combustion apparatus with arrangements for burning uncombusted material from primary combustion
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23GCREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
    • F23G2209/00Specific waste
    • F23G2209/30Solid combustion residues, e.g. bottom or flyash

Definitions

  • the present invention relates to an apparatus and a method promoting the combustion completion or postcombustion of unburnt matter still contained in heavy ash arising from combustion of solid fuel of any kind in combustion chambers for powdered fuel, when said ash falls out from the combustion chamber.
  • This invention will produce the greater advantages the higher is the contents of unburnt matter in the ash.
  • the present invention can be considered a development of the invention disclosed in EP- 0 252 967 B1, applicable in those cases where the contents of unbumt matter is high and/or the postcombustion degree that can be attained with the apparatus disclosed in said prior document is not satisfactory.
  • the apparatus disclosed in said document claimed the increase of efficiency arising from the reduction of unburnt matter in heavy ash because of the introduction through suitable openings of air that travelled in countercurrent to the ash flow and promoted the combustion completion in view of the consequent oxidising ambient.
  • Document EP 0471055 B1 (corresponding to WO-A-91/13293) discloses a system for discharging bottom ash from steam producing boilers, wherein the conveyor belt is partially sealed to prevent ashes falling through the belt and counter current air is introduced into the system only at the upper extremity of the ash discharge extractor and postcooler, flowing over the ashes.
  • the main object of the present invention is to provide for an apparatus and a method solving these problems so as to allow:
  • FIG. 1 of the drawings shows in a diagrammatic way one embodiment of the apparatus 10 according to the present invention, comprising:
  • the postcombustion belt 18 is arranged directly below the combustion chamber 14 and receives ash 34 continuously falling from said combustion chamber.
  • the belt is moved to such a speed to obtain the optimal combination of thickness of the ash layer and ash residence time on the belt as a function of the amount of ash produced. Indeed if on the one hand an increase of the residence time promotes a postcombustion increase, on the other hand it causes an increase of the ash layer thickness on the belt that reduces diffusion of air necessary for the combustion inside the ash layer.
  • the regulation of the optimal combination may be effected only once, when the operative conditions are so stable to allow it, or more frequently in a continuous way by means of a continuous measurement of the actual thickness of ash 34 on the belt 18 for instance through a device 36 shown in Figure 2.
  • Said measuring device 36 comprises a blade 38 shaped so as not to hinder substantially the advancement of ash 34, said blade 38 being hinged to the top of the container 24. From the value of angle ⁇ formed by said blade lying on the ash bed, it is possible to know the thickness of said bed. Said blade 38 has also another function of great relevance in the method of the invention, that will be described hereinafter.
  • the belt postcombustion zone A is extended farther than the belt stretch under the boiler, so as to give a suitable residence time also to ash deposited on the belt in proximity of the outlet.
  • the extension of the postcombustion zone outside the boiler will be determined for each single plant as a function of the general configuration of the boiler area and the desired postcombustion degree. As it was stated hereinbefore, it is fundamental to keep the temperature at high values, but harmonized with the necessity of safeguarding the mechanical characteristics of the components involved in the high temperature zone, namely the belt and the support rollers.
  • the lateral walls 40 of the postcombustion zone A, as well as the cover of said zone at the outlet of the postcombustion chamber are thermally insulated.
  • the air inlet ports 42 must be of limited size in the belt advancement direction so as to limit ash fall through said ports.
  • a positive pressure differential between the area below the belt and the area above the belt, air will be forced to pass through said inlet ports.
  • the combustion chambers normally operate under a light vacuum, it will be necessary to seal as far as possible the area above the belt. In this way the area above the belt will be at the said vacuum level of the combustion chamber, while the area under the belt will be at the pressure close to the atmospheric one. To this end, it will be the thickness of the ash 34 layer to limit the lateral penetrations through the area under the belt 18 and the area above the belt 18 for the whole length of said belt.
  • the postcombustion zone A may be divided, during belt advancement, as follows (see Figure 7):
  • ash is hit by cold air introduced into the apparatus through a suitable opening so as to start the cooling process.
  • Said cooling process is completed when discharging the material from the belt to the free atmosphere, at the area where it falls toward the primary crusher 30 as well as at the subsequent contact heat exchanger 32.
  • hot ash are cooled both by the direct contact with cold air and contact with metal plates 54 in turn hit by upwards ascendent cold air; these plates may be provided with lower fins (not shown) so as to increase the thermal exchange with the air and keep their temperature at minimal values.
  • Air ascending from the cooler to the postcombustor, forming totally or partially the combustion air, will be delivered to the zone where ash is discharged from the belt through a duct of suitable size in order to minimize loss of head. This feature is shown in Figure 8.
  • a cold air inlet 56 through the opening at the end of the postcombustion zone; an air inlet 58 from the final cooler 32; a drum 60 driving the belt; said belt 18; the ash layer 34 on the belt; the lateral channels or troughs 62 in which air is forced to move so as to enter again the combustion chamber, being attracted by the vacuum; and the lower trough 64 having the double function of deviating the possible fall of ash particles at the sides of the extractor container, so as to avoid said fall on the return stretch of the belt and the consequent erosion, and of forming together with the lateral channels a duct distributing hot air under the belt for the subsequent passage through the plate slots.
  • a variant of the illustrated situation may occur in case air passing through the ash layer is insufficient to obtain a good combustion.
  • one may use air under positive pressure coming from an air heater, namely at a temperature adequate for a good combustion. Said air will be conveyed under the belt, where it will be forced to pass through the ash layer in view of a confinement obtained through the belt, the lower trough (that must be arranged as close as possible to the container) and two vertical diaphragms between trough and belt, placed one at the beginning and the other at the end of the postcombustion zone, so as to limit air escape.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Thermal Sciences (AREA)
  • Gasification And Melting Of Waste (AREA)
  • Processing Of Solid Wastes (AREA)
  • Solid-Fuel Combustion (AREA)

Abstract

An apparatus and method to promote the completion of the combustion of unburnt matter contained in ash arising from the combustion of solid fuel are described. The apparatus for the postcombustion of ash arising from the combustion of solid fuel comprises a combustion chamber (14) and an extractor (16) arranged so as to receive ash falling from the combustion chamber, the unburnt matter of said ash having to be burnt, said extractor comprising in turn a metallic belt (18) for ash transportation, said apparatus being characterized in that said conveyor belt is provided with parts or openings for the passage of combustion feeding air, said air thus passing through said ash during at least a part of the forward advancing stretch of said belt. <IMAGE>

Description

  • The present invention relates to an apparatus and a method promoting the combustion completion or postcombustion of unburnt matter still contained in heavy ash arising from combustion of solid fuel of any kind in combustion chambers for powdered fuel, when said ash falls out from the combustion chamber. This invention will produce the greater advantages the higher is the contents of unburnt matter in the ash.
  • The present invention can be considered a development of the invention disclosed in EP- 0 252 967 B1, applicable in those cases where the contents of unbumt matter is high and/or the postcombustion degree that can be attained with the apparatus disclosed in said prior document is not satisfactory.
  • The apparatus disclosed in said document claimed the increase of efficiency arising from the reduction of unburnt matter in heavy ash because of the introduction through suitable openings of air that travelled in countercurrent to the ash flow and promoted the combustion completion in view of the consequent oxidising ambient.
  • This result was experimentally verified in many applications of said prior invention, for example in the usual boilers using fine coal powder, as a substitution for the wet extraction systems like the so-called flooded hopper, where it gave a reduction of the unburnt matter to about three-quarters of the conventional amount. However the reduction in other cases was not equally significant, for instance this happened in an application for extraction of ash from a boiler using lignite, where the reduction of the ash unburnt matter was about 10 - 20%.
  • The reasons of this different behaviour are mainly due to two interrelated factors: ash reactivity (or postcombustion velocity) and temperature sinking. Indeed in case of lignite and generally of poor fuel, low heating power and high ash contents cause the ash leaving the combustion chamber to undergo a decrease of temperature.
  • Document EP 0471055 B1 (corresponding to WO-A-91/13293) discloses a system for discharging bottom ash from steam producing boilers, wherein the conveyor belt is partially sealed to prevent ashes falling through the belt and counter current air is introduced into the system only at the upper extremity of the ash discharge extractor and postcooler, flowing over the ashes.
  • Document WO-A-96/29546 does not disclose a postcombustion chamber which is part of a combustion chamber. The combustion of ashes takes place in the chamber where air is blown over and not through the ashes.
  • In the light of the above drawbacks, the main object of the present invention is to provide for an apparatus and a method solving these problems so as to allow:
  • 1. to keep the ash carried by the conveyor belt for the required amount of time at such a temperature to allow a significant reduction of unburnt matter still contained in the ash; and
  • 2. to carry out subsequently the cooling of said ash in order to discharge it from the system at a temperature compatible with the usual transportation systems to the final storage bin.
  • The above mentioned and other objects are brilliantly attained by the apparatus recited in independent claim 1 and the method set forth in independent claim 12. Further advantageous features of the apparatus and the method are indicated in the corresponding dependent claims. Now follows a detailed description of the apparatus and the method according to the present invention, given as an example to be read in connection with the accompanying sheets of illustrative drawings in which:
  • Figure 1 is a diagrammatic general view of one embodiment of the apparatus;
  • Figure 2 is a diagrammatic partial view of a possible embodiment of an ash measuring device;
  • Figure 3 is a cross-sectional view of the postcombustor arranged under the combustion chamber;
  • Figure 4 is a partial top plan view of a known system of plate conveyor belt;
  • Figure 5 is a diagrammatic detail of the air inlet ports;
  • Figure 6 shows diagrammatically how the ash thickness limits the lateral penetrations through the areas above and under the belt;
  • Figure 7 shows diagrammatically the postcombustion zone;
  • Figure 8 is a partial diagrammatic view of the ash discharge zone; and
  • Figure 9 is a diagram of the air circulation in the final extraction part.
  • Like or equal reference numerals in the various figures of the drawings indicate equal or functionally equivalent elements.
  • Figure 1 of the drawings shows in a diagrammatic way one embodiment of the apparatus 10 according to the present invention, comprising:
  • a) a seal 12 between boiler 14 and extractor 16, said seal expanding downwards in view of thermal expansion. Said seal can be mechanical (as shown in Figure 1) or hydraulic. As said seal is known, it will not be described in detail, but it is sufficient to state that the seal avoids introduction of improper air between boiler and postcombustion belt;
  • b) the extractor 16, comprising a metallic belt 18 continuously running and allowing postcombustion of ash 34. Along the path of the extraction belt 18 one can recognize two zones having different functions: a first postcombustion hot zone A and a second ash cooling cold zone B;
  • c) a system 22 of recovery of fine material depositing on the bottom of container 24 in which the belt extractor 18 is arranged. Said system 22 consists of a chain 26 provided with doctor blades 28 so as to collect the fine material and carry it to the ash discharge point C;
  • d) a crusher 30 arranging to crush possible ash lumps formed in the combustion chamber or on said postcombustion belt; and
  • e) a final ash cooler 32 carrying out the final cooling to a temperature compatible with the downstream transportation systems.
  • The postcombustion belt 18 is arranged directly below the combustion chamber 14 and receives ash 34 continuously falling from said combustion chamber. The belt is moved to such a speed to obtain the optimal combination of thickness of the ash layer and ash residence time on the belt as a function of the amount of ash produced. Indeed if on the one hand an increase of the residence time promotes a postcombustion increase, on the other hand it causes an increase of the ash layer thickness on the belt that reduces diffusion of air necessary for the combustion inside the ash layer. The regulation of the optimal combination may be effected only once, when the operative conditions are so stable to allow it, or more frequently in a continuous way by means of a continuous measurement of the actual thickness of ash 34 on the belt 18 for instance through a device 36 shown in Figure 2. Said measuring device 36 comprises a blade 38 shaped so as not to hinder substantially the advancement of ash 34, said blade 38 being hinged to the top of the container 24. From the value of angle α formed by said blade lying on the ash bed, it is possible to know the thickness of said bed. Said blade 38 has also another function of great relevance in the method of the invention, that will be described hereinafter.
  • The belt postcombustion zone A is extended farther than the belt stretch under the boiler, so as to give a suitable residence time also to ash deposited on the belt in proximity of the outlet. The extension of the postcombustion zone outside the boiler will be determined for each single plant as a function of the general configuration of the boiler area and the desired postcombustion degree. As it was stated hereinbefore, it is fundamental to keep the temperature at high values, but harmonized with the necessity of safeguarding the mechanical characteristics of the components involved in the high temperature zone, namely the belt and the support rollers. To this purpose, as shown in Figure 3, the lateral walls 40 of the postcombustion zone A, as well as the cover of said zone at the outlet of the postcombustion chamber, are thermally insulated.
  • This configuration allows to limit thermal dispersion sidewards and upwards, but it is not sufficient to obtain the desired thermal behaviour. In this connection it is of fundamental importance the amount of air introduced to the system: said amount must obviously be sufficient to assure a good oxidizing ambient, thus in a large excess of the stoichiometric quantity, but at the same time limited so as not to cool excessively the relevant zone as it is to be noted that air enters the postcombustion zone at a temperature which is considerable lower than that desired in the postcombustion zone. The correct amount of postcombustion air moreover must be introduced in the postcombustion zone in such a way to promote air diffusion from below to the interior of the ash layer. This can be obtained by making suitable air inlet ports 42 (Figure 5) between the plates 44 without modifying the geometry of the plate conveyor belt shown in Figure 4.
  • The air inlet ports 42 must be of limited size in the belt advancement direction so as to limit ash fall through said ports. By keeping a positive pressure differential between the area below the belt and the area above the belt, air will be forced to pass through said inlet ports. To obtain said positive pressure difference, taking into account that the combustion chambers normally operate under a light vacuum, it will be necessary to seal as far as possible the area above the belt. In this way the area above the belt will be at the said vacuum level of the combustion chamber, while the area under the belt will be at the pressure close to the atmospheric one. To this end, it will be the thickness of the ash 34 layer to limit the lateral penetrations through the area under the belt 18 and the area above the belt 18 for the whole length of said belt.
  • The postcombustion zone A may be divided, during belt advancement, as follows (see Figure 7):
    • a start area A1: in this area a slope 46 will convey ash 34 on the belt 18. The purpose of the slope is to restrict as far as possible the belt position where the ash layer is not significant. Between slope 46 and belt 18 it is possible to place a pad 48 fixed to said slope 46 to limit the inevitable reentry of air between the stationary slope and moving belt plates. In this area the lateral air penetration to the postcombustion zone (air that would not come in intimate contact with ash) must be limited by pads fixed to the transition duct. The slope geometry will be suitable to optimize ash distribution on the belt: for instance, if ash would tend to accumulate in the belt middle portion, the slope can be shaped to increase ash distribution to the belt sides or viceversa. Moreover a dam 50 is provided in the area under the belt, so as to create a loss of head at the air passage and limit air penetration through the belt slots in this area.
    • an intermediate area A2: in this area the ash layer, even if it is not yet at the maximum height, reached already such a thickness to oblige the postcombustion air 52 to pass through ash so as to be attracted by the vacuum existing in the combustion chamber. Therefore in this area the differential pressure between outer and inner postcombustion area will be greater than in the first area, even if not yet at the maximum value. If required, an additional air shield may be inserted;
    • and a final area A3: this area is now outside the combustion chamber and the thickness of the ash layer is constant at the maximum value. The differential pressure between the outer area under the belt and the postcombustion area is at the maximum level and is about equal to the difference between the atmospheric pressure and the vacuum in the combustion chamber. The final area A3 ends with the above mentioned blade 38, which has also the task of avoiding direct passage of air from the cooling zone to the postcombustion zone so as to force air to pass from below through the ash layer and at the same time allow ash to go out from the postcombustion zone.
  • Both in the intermediate and the final zone, if the amount of air required for the combustion exceeds that succeeding to pass through the ash pushed by the differential pressure, it is advisable to provide for a supplemental inlet through the lateral channels 70 shown in Figure 6.
  • At the outlet of the combustion zone, ash is hit by cold air introduced into the apparatus through a suitable opening so as to start the cooling process. Said cooling process is completed when discharging the material from the belt to the free atmosphere, at the area where it falls toward the primary crusher 30 as well as at the subsequent contact heat exchanger 32. In the latter device hot ash are cooled both by the direct contact with cold air and contact with metal plates 54 in turn hit by upwards ascendent cold air; these plates may be provided with lower fins (not shown) so as to increase the thermal exchange with the air and keep their temperature at minimal values.
  • Air ascending from the cooler to the postcombustor, forming totally or partially the combustion air, will be delivered to the zone where ash is discharged from the belt through a duct of suitable size in order to minimize loss of head. This feature is shown in Figure 8.
  • Lastly in Figure 9 the diagram of air circulation in the final part of the extractor is shown, and it is to be noted that the air is guided to the lateral channels and under the belt, where it will then pass through the ash layer and above it, as described hereinbefore, in view of the vacuum existing in the combustion chamber.
  • In said diagram one can see the following elements: a cold air inlet 56, through the opening at the end of the postcombustion zone; an air inlet 58 from the final cooler 32; a drum 60 driving the belt; said belt 18; the ash layer 34 on the belt; the lateral channels or troughs 62 in which air is forced to move so as to enter again the combustion chamber, being attracted by the vacuum; and the lower trough 64 having the double function of deviating the possible fall of ash particles at the sides of the extractor container, so as to avoid said fall on the return stretch of the belt and the consequent erosion, and of forming together with the lateral channels a duct distributing hot air under the belt for the subsequent passage through the plate slots.
  • From this diagram of air circulation one can see also that in the cooling zone there will be a positive differential pressure, even if it is minimal, between the area above the ash bed and that under the belt in the cooling zone: this fact will prevent air passage in this zone from below through the ash bed, thus stopping continuation of the combustion.
  • A variant of the illustrated situation may occur in case air passing through the ash layer is insufficient to obtain a good combustion. In this case one may use air under positive pressure coming from an air heater, namely at a temperature adequate for a good combustion. Said air will be conveyed under the belt, where it will be forced to pass through the ash layer in view of a confinement obtained through the belt, the lower trough (that must be arranged as close as possible to the container) and two vertical diaphragms between trough and belt, placed one at the beginning and the other at the end of the postcombustion zone, so as to limit air escape.
  • With such a configuration, air coming from the final cooler will be taken without hindrance from the vacuum of the combustion chamber, and to this end the blade of Figure 2 should be modified so as to maintain its function of measuring the ash level on the belt, but not the function to form a division between the two ambients of the postcombustion zone and the cooling zone.
  • Although the invention was described hereinbefore in a very detailed way, it will be apparent to a man skilled in the art that many modifications, variations and substitutions of elements with other functionally equivalent ones may be resorted to the invention, without departing however from its scope of protection as defined in the appended claims.

Claims (21)

  1. A combustion chamber (14) with an apparatus (10) for postcombustion of ash (34) from combustion of solid fuels comprising a combustion chamber (14) under vacuum and an extractor (16) arranged for receiving from said combustion chamber (14) the fall of ash, whose unburnt matter must be burnt, said extractor (16) comprising in turn an ash carrying metal conveyor belt (18), characterized in that said conveyor belt (18) is provided with ports or slots (42) for the passage of postcombustion air (52), said postcombustion air passing through the ash (34) during at least a part of the advancement stretch of the belt (18).
  2. The apparatus according to Claim 1, characterized in that means are provided on at least a part of said advancement stretch of the belt, to make a negative differential pressure between the area above the belt and that under the belt.
  3. The apparatus according to any of the preceding claims, characterized in that it further comprises air heating means (62, 64) to create air under positive pressure, said air being conveyed under the belt and forced to pass through the ash.
  4. The apparatus according to any of the preceding claims, characterized in that it further comprises lateral channels (70) in which ash postcombustion or combustion feeding supplementary air is guided, in addition to the air under the belt, said additional air then passing above the ash bed due to the vacuum existing in the combustion chamber (14).
  5. The apparatus according to any of the preceding claims, characterized in that said extractor (16) comprises a postcombustion zone (A) and an ash cooling zone (B), said zones being preferably divided by separating means such as moving blades (38).
  6. The apparatus according to Claim 5, characterized in that the swinging or rotation angle (α) of the blade (38) lying on the ash bed is related to the thickness of the ash bed (34) on the belt (18).
  7. The apparatus according to any of the preceding claims, characterized in that it comprises cold air inlet means (56) at the end of the postcombustion zone (A), or at the beginning of the cooling zone (B) and air inlet means (58) from a final cooler (32), the air so introduced in the cooling zone (B) making a positive differential pressure preventing air to pass through the ash bed (34) on the belt doubled passage (18), thus stopping continuation of the combustion.
  8. The apparatus according to any of the preceding claims, characterized in that it comprises means (22) to recover fine ash fallen from the belt (18), said recovery means comprising a chain (26) provided with doctor blades (28) or the like, said blades (28) being arranged under the belt (18).
  9. The apparatus according to any of the preceding claims, characterized in that it comprises distribution means (46) adapted to make a uniform ash distribution on the belt (18).
  10. The apparatus according to claim 9, characterized in that the space between said distribution means (46) and said conveyor belt (18) is sealed by yieldable means such as pads (48).
  11. The apparatus according to any of the preceding claims, characterized in that it further comprises crushing means (30) for crushing any possible ash lumps.
  12. A method of postcombustion of heavy ash with high contents of unburnt matter, arising from a combustion chamber (14), comprising the steps of: depositing said ash on the conveyor belt (18) of an extractor (16); providing along the forward run of said belt an ash postcombustion zone (A) and an ash cooling zone (B); and taking at least a part of the air used for ash cooling, characterized by the steps of causing at least a part of the air taken from the cooling zone (B) to pass through said ash in the postcombustion zone (A), by means of ports or openings (42) in said belt (18), and drawing the postcombustion air (52) into the combustion chamber (14).
  13. The method according to claim 12, characterized in that there is a negative differential pressure between the area above the belt and the area under the belt.
  14. The method according to claim 12 or 13, characterized in that it further comprises the step of limiting the lateral penetrations of air through the area under the belt and the area above the belt (18) by the thickness of the ash bed (34).
  15. The method according to any of claims 12 to 14, characterized in that the belt (18) is moved at a speed related to the thickness of the ash bed (34).
  16. The method according to any of claims12 to 15, characterized in that said postcombustion air comes from a cooler (32).
  17. The method according to any of claims 12 to 16, characterized in that said postcombustion air is air at a positive pressure coming from a heater.
  18. The method according to any of claims 12 to 17, characterized in that the step of causing air to pass through said ash bed (34) is carried out by conveying air under the belt (18) and through lateral channels (62).
  19. The method according to any of claims 12 to 18, characterized by the step of conveying ash from the combustion chamber (14) to the belt (18) through distribution means (46) for the uniform ash distribution on the belt.
  20. The method according to claim 19, characterized by comprising the step of sealing the area between said distribution means (46) and the bet plates (44) by means of a pad (48).
  21. The method according to any of claims 12 to 19, characterized by providing a separation (38) between the postcombustion zone (A) and the cooling zone (B).
EP99200062A 1998-01-15 1999-01-12 Apparatus and method for postcombustion of heavy ash with high contents of unburnt matter Expired - Lifetime EP0931981B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT98MI000051A IT1298162B1 (en) 1998-01-15 1998-01-15 EQUIPMENT AND METHOD FOR THE AFTERBURNING OF BOTTOM ASH WITH HIGH UNBURNED CONTENT
ITMI980051 1998-01-15

Publications (3)

Publication Number Publication Date
EP0931981A2 EP0931981A2 (en) 1999-07-28
EP0931981A3 EP0931981A3 (en) 2000-01-19
EP0931981B1 true EP0931981B1 (en) 2003-12-10

Family

ID=11378571

Family Applications (1)

Application Number Title Priority Date Filing Date
EP99200062A Expired - Lifetime EP0931981B1 (en) 1998-01-15 1999-01-12 Apparatus and method for postcombustion of heavy ash with high contents of unburnt matter

Country Status (6)

Country Link
EP (1) EP0931981B1 (en)
AT (1) ATE256270T1 (en)
DE (1) DE69913395T2 (en)
DK (1) DK0931981T3 (en)
ES (1) ES2213327T3 (en)
IT (1) IT1298162B1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100180807A1 (en) * 2007-02-20 2010-07-22 Mario Magaldi Plant and method for dry extracting/cooling heavy ashes and for controlling the combustion of high unburnt content residues
DE102010052404A1 (en) * 2010-11-24 2012-05-24 Clyde Bergemann Drycon Gmbh Method and device for controlling combustion in a combustion boiler

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19935597C2 (en) * 1999-08-03 2002-03-14 Steag Encotec Gmbh heating
ITMI20020353A1 (en) * 2002-02-21 2003-08-21 Magaldi Ricerche & Brevetti EXTRACTOR / COOLER OF BULK MATERIALS BY USING A CONVEYOR BELT EQUIPMENT EQUIPPED WITH PERFORATED PLATES AND PROVIDED WITH
ITMI20020744A1 (en) * 2002-04-09 2003-10-09 Magaldi Ricerche & Brevetti AIR AND WATER COOLING CONVEYOR OF HOT BULK MATERIALS
ITMI20040225A1 (en) * 2004-02-12 2004-05-12 Magaldi Ricerche & Brevetti S R L PRE-CRUSHING DEVICE FOR A TRANSPORTED AND COOLER OF HOT MATERIALS HOT BULK
US7559725B2 (en) 2005-11-14 2009-07-14 General Kinematics Corporation Conveyor for and method of conveying heated material
ITMI20061010A1 (en) * 2006-05-23 2007-11-24 Magaldi Power Spa COOLING SYSTEM FOR DRY EXTRACTION OF HEAVY ASH FOR BOILERS DURING THE HOPPER STORAGE PHASE
BRPI0621955A2 (en) * 2006-08-22 2011-12-20 Magaldi Power Spa system for extracting and cooling dry combustion waste of a type suitable for use in combination with a combustion chamber and method for extracting and dry cooling combustion waste from a combustion chamber
ITRM20070277A1 (en) * 2007-05-21 2008-11-22 Magaldi Ind Srl DRY EXTRACTION / COOLING SYSTEM OF ASTEROGUE OF HETEROGENEOUS MATERIALS WITH THE CONTROL OF THE RE-ENTRY OF AIR IN THE COMBUSTION CHAMBER.
DE102008052085B4 (en) * 2008-10-17 2020-06-18 Clyde Bergemann Dryc0N Gmbh System with a conveyor for combustion boilers
IT1396049B1 (en) * 2009-09-24 2012-11-09 Magaldi Ind Srl ASH EXTRACTION AND TRANSPORTATION SYSTEM READ THROUGH THE STEEL TAPE CONVEYOR.
DE102010024020B4 (en) * 2010-06-16 2019-08-01 Clyde Bergemann Drycon Gmbh Conveying means and method for conveying hot material
DE102010033307A1 (en) * 2010-08-04 2012-02-09 Clyde Bergemann Drycon Gmbh Apparatus and method for post-burning hot material on a conveyor
US8826835B1 (en) 2011-01-18 2014-09-09 General Kinematics Corporation Controlling carbon content in conveyed heated material
IT1405071B1 (en) 2011-01-21 2013-12-16 Magaldi Power Spa PLANT AND METHOD OF EXTRACTION AND COOLING OF ASH WITH INCREASE OF THE TOTAL EFFICIENCY OF THE BOILER.
ITRM20120351A1 (en) 2012-07-20 2014-01-21 Magaldi Ind Srl DRY TRANSPORT SYSTEM OF STORAGE AND / OR HETEROGENEOUS MATERIALS.
US10088233B2 (en) 2013-01-31 2018-10-02 General Kinematics Corporation Vibratory dryer with mixing apparatus
CN114704845A (en) * 2022-03-25 2022-07-05 西安热工研究院有限公司 Dry slag discharging automatic control system and method with high-efficiency heat exchange and low air leakage rate
CN115452646B (en) * 2022-08-24 2023-05-30 淮南矿业(集团)有限责任公司顾桥煤矿 Quick detection device and method for ash content of coal

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1188247B (en) * 1986-01-10 1988-01-07 Magaldi Mario PROCEDURE AND EQUIPMENT FOR THE CONTINUOUS DRY EXTRACTION OF HEAVY ASH
EP0259967B1 (en) 1986-08-01 1994-03-23 Fujitsu Limited Directory memory
US4723494A (en) * 1987-01-12 1988-02-09 Anclif Equities Inc. Incinerator discharge systems
IT1241408B (en) * 1990-03-02 1994-01-14 Mario Magaldi HEAVY ASH DISCHARGE SYSTEM FROM BOILERS FOR STEAM PRODUCTION
US5216967A (en) * 1992-03-16 1993-06-08 Sam Mormino Stand-alone, commercial refuse-burning apparatus
US5868084A (en) * 1995-03-20 1999-02-09 U.S. Scientific, L.L.C. Apparatus and process for carbon removal from fly ash
IT1276747B1 (en) * 1995-06-19 1997-11-03 Magaldi Ricerche & Brevetti BULK MATERIALS EXTRACTOR / COOLER

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100180807A1 (en) * 2007-02-20 2010-07-22 Mario Magaldi Plant and method for dry extracting/cooling heavy ashes and for controlling the combustion of high unburnt content residues
DE102010052404A1 (en) * 2010-11-24 2012-05-24 Clyde Bergemann Drycon Gmbh Method and device for controlling combustion in a combustion boiler

Also Published As

Publication number Publication date
ES2213327T3 (en) 2004-08-16
DE69913395D1 (en) 2004-01-22
DE69913395T2 (en) 2004-10-07
DK0931981T3 (en) 2004-04-05
ITMI980051A1 (en) 1999-07-15
EP0931981A2 (en) 1999-07-28
IT1298162B1 (en) 1999-12-20
ATE256270T1 (en) 2003-12-15
EP0931981A3 (en) 2000-01-19

Similar Documents

Publication Publication Date Title
EP0931981B1 (en) Apparatus and method for postcombustion of heavy ash with high contents of unburnt matter
US4321877A (en) Gasification furnace
JPH0449164Y2 (en)
US3133804A (en) Apparatus for treating molten ash or slag
US4156394A (en) Method and apparatus for thermally economical incineration of waste
US5081937A (en) System for treating waste material in a molten state
EP0836697A1 (en) Conveyor/cooler of loose materials
US4389242A (en) Interior arrangement for direct reduction rotary kilns and method
EP0687855B1 (en) Circulating fluidized bed reactor for low grade fuels
EP0257858B1 (en) Furnace
US4510892A (en) Seal for boiler water wall
US3808989A (en) Method and arrangement for jointly combusting household refuse and sewage sludge
US3970011A (en) Combustion with fluidizable bed
US4336131A (en) Gasification furnace with discharge hopper
EP0437407B1 (en) Method for sintering fine iron ore using dual ignition system
US2996292A (en) Gravity-fed combustion equipment applying crossfeed ignition principle
US2033685A (en) Boiler furnace
US3664278A (en) Method and apparatus for incinerating solid materials
US5899149A (en) Incineration grate with ducts for conveying a heat transmission medium
US4466827A (en) Method for melting metals
US4089697A (en) Manufacture of Portland cement
EP0846919B1 (en) Burning/melting method of waste melting furnace
US4726765A (en) Combustor drum hole shields
EP0467436B1 (en) Plant for the thermodestruction of industrial wastes, especially tyres
US2694989A (en) Apparatus for the automatic firing of solid fuel such as coke and similar fuels, and in particular relating to the firing of large coke

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

17P Request for examination filed

Effective date: 20000713

AKX Designation fees paid

Free format text: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AXX Extension fees paid

Free format text: AL;LT;LV;MK;RO;SI

17Q First examination report despatched

Effective date: 20021021

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE DE DK ES FI FR GB GR IE IT NL SE

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REF Corresponds to:

Ref document number: 69913395

Country of ref document: DE

Date of ref document: 20040122

Kind code of ref document: P

REG Reference to a national code

Ref country code: SE

Ref legal event code: TRGR

REG Reference to a national code

Ref country code: DK

Ref legal event code: T3

REG Reference to a national code

Ref country code: GR

Ref legal event code: EP

Ref document number: 20040400875

Country of ref document: GR

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2213327

Country of ref document: ES

Kind code of ref document: T3

PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

PLBQ Unpublished change to opponent data

Free format text: ORIGINAL CODE: EPIDOS OPPO

ET Fr: translation filed
PLAX Notice of opposition and request to file observation + time limit sent

Free format text: ORIGINAL CODE: EPIDOSNOBS2

26 Opposition filed

Opponent name: CLYDE BERGEMANN GMBH

Effective date: 20040910

NLR1 Nl: opposition has been filed with the epo

Opponent name: CLYDE BERGEMANN GMBH

PLAX Notice of opposition and request to file observation + time limit sent

Free format text: ORIGINAL CODE: EPIDOSNOBS2

PLAY Examination report in opposition despatched + time limit

Free format text: ORIGINAL CODE: EPIDOSNORE2

PLAH Information related to despatch of examination report in opposition + time limit modified

Free format text: ORIGINAL CODE: EPIDOSCORE2

PLBC Reply to examination report in opposition received

Free format text: ORIGINAL CODE: EPIDOSNORE3

PLCK Communication despatched that opposition was rejected

Free format text: ORIGINAL CODE: EPIDOSNREJ1

APBP Date of receipt of notice of appeal recorded

Free format text: ORIGINAL CODE: EPIDOSNNOA2O

APAH Appeal reference modified

Free format text: ORIGINAL CODE: EPIDOSCREFNO

APBQ Date of receipt of statement of grounds of appeal recorded

Free format text: ORIGINAL CODE: EPIDOSNNOA3O

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IE

Payment date: 20100121

Year of fee payment: 12

APBU Appeal procedure closed

Free format text: ORIGINAL CODE: EPIDOSNNOA9O

PLBN Opposition rejected

Free format text: ORIGINAL CODE: 0009273

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: OPPOSITION REJECTED

27O Opposition rejected

Effective date: 20100617

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20110112

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20130213

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20130122

Year of fee payment: 15

Ref country code: BE

Payment date: 20130128

Year of fee payment: 15

Ref country code: GR

Payment date: 20130117

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 20130111

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FI

Payment date: 20140122

Year of fee payment: 16

Ref country code: DK

Payment date: 20140121

Year of fee payment: 16

Ref country code: SE

Payment date: 20140121

Year of fee payment: 16

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: ES

Payment date: 20140124

Year of fee payment: 16

BERE Be: lapsed

Owner name: *MAGALDI RICERCHE E BREVETTI S.R.L.

Effective date: 20140131

REG Reference to a national code

Ref country code: NL

Ref legal event code: V1

Effective date: 20140801

REG Reference to a national code

Ref country code: AT

Ref legal event code: MM01

Ref document number: 256270

Country of ref document: AT

Kind code of ref document: T

Effective date: 20140112

REG Reference to a national code

Ref country code: GR

Ref legal event code: ML

Ref document number: 20040400875

Country of ref document: GR

Effective date: 20140801

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20140801

Ref country code: GR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20140801

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20140930

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20140131

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20140112

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20140131

REG Reference to a national code

Ref country code: DK

Ref legal event code: EBP

Effective date: 20150131

REG Reference to a national code

Ref country code: SE

Ref legal event code: EUG

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20150112

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20150113

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20150131

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20160226

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20150113

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20160113

Year of fee payment: 18

Ref country code: DE

Payment date: 20160120

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20160120

Year of fee payment: 18

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 69913395

Country of ref document: DE

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20170112

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170801

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170112

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170112