GB2030275A - Fluidized bed incinerator - Google Patents

Fluidized bed incinerator Download PDF

Info

Publication number
GB2030275A
GB2030275A GB7930321A GB7930321A GB2030275A GB 2030275 A GB2030275 A GB 2030275A GB 7930321 A GB7930321 A GB 7930321A GB 7930321 A GB7930321 A GB 7930321A GB 2030275 A GB2030275 A GB 2030275A
Authority
GB
United Kingdom
Prior art keywords
fluidized
bed
combustion chamber
medium
heat exchanger
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.)
Granted
Application number
GB7930321A
Other versions
GB2030275B (en
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.)
HAMJERN AS
Original Assignee
HAMJERN AS
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
Application filed by HAMJERN AS filed Critical HAMJERN AS
Publication of GB2030275A publication Critical patent/GB2030275A/en
Application granted granted Critical
Publication of GB2030275B publication Critical patent/GB2030275B/en
Expired legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
    • B01J8/18—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles
    • B01J8/1809—Controlling processes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C10/00—Fluidised bed combustion apparatus
    • F23C10/18—Details; Accessories
    • F23C10/24—Devices for removal of material from the bed
    • F23C10/26—Devices for removal of material from the bed combined with devices for partial reintroduction of material into the bed, e.g. after separation of agglomerated parts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
    • B01J2208/00008—Controlling the process
    • B01J2208/00017—Controlling the temperature
    • B01J2208/00026—Controlling or regulating the heat exchange system
    • B01J2208/00035—Controlling or regulating the heat exchange system involving measured parameters
    • B01J2208/00044—Temperature measurement
    • B01J2208/00061—Temperature measurement of the reactants
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
    • B01J2208/00008—Controlling the process
    • B01J2208/00017—Controlling the temperature
    • B01J2208/00106—Controlling the temperature by indirect heat exchange
    • B01J2208/00115—Controlling the temperature by indirect heat exchange with heat exchange elements inside the bed of solid particles
    • B01J2208/0015—Plates; Cylinders
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
    • B01J2208/00008—Controlling the process
    • B01J2208/00017—Controlling the temperature
    • B01J2208/00106—Controlling the temperature by indirect heat exchange
    • B01J2208/00168—Controlling the temperature by indirect heat exchange with heat exchange elements outside the bed of solid particles
    • B01J2208/00256—Controlling the temperature by indirect heat exchange with heat exchange elements outside the bed of solid particles in a heat exchanger for the heat exchange medium separate from the reactor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
    • B01J2208/00008—Controlling the process
    • B01J2208/00017—Controlling the temperature
    • B01J2208/00106—Controlling the temperature by indirect heat exchange
    • B01J2208/00265—Part of all of the reactants being heated or cooled outside the reactor while recycling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
    • B01J2208/00008—Controlling the process
    • B01J2208/00548—Flow

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Fluidized-Bed Combustion And Resonant Combustion (AREA)
  • Incineration Of Waste (AREA)
  • Treating Waste Gases (AREA)
  • Processing Of Solid Wastes (AREA)

Abstract

There is provided a method and an apparatus for the operation of a fluidized-bed incinerator wherein a portion of the fluidized-bed medium (2) of the furnace is caused to pass a heat exchanger (8) during tapping from the combustion chamber of the furnace, and after cooling in the heat exchanger (8) is returned to the fluidized bed in the combustion chamber. The cooled fluidized-bed medium may be returned directly to the fluidized bed in the combustion chamber or it may be returned to the combustion chamber in an upper portion thereof and be allowed to fall through a distributor (13) so that it cools the zone above the fluidized bed at the same time as the medium is heated by waste gases from the combustion. The tapping of fluidized- bed medium is preferably controlled by a thermostat sensing the temperature of the fluidized bed. In an alternative arrangement the heat exchanger may be within a lower part of the fluidized bed. <IMAGE>

Description

SPECIFICATION Method of operating a fluidised-bed incinerator, and means for carrying out the method The present invention relates to a method of operating a fluidized-bed incinerator having a combustion chamber containing fluidized-bed medium which is heated during combustion of fuel in the combustion chamber. Further, the invention relates to an apparatus for the operation of a fluidized-bed incinerator in accordance with the method, wherein the fluidized-bed incinerator comprises a combustion chamber with a fluidizedbed medium contained therein.
In a fluidized-bed incinerator, fuel, e.g. garbage, is fed to the combustion chamber of the furnace wherein the fuel is mixed with a carrying medium, such as sand, which is fluidized e.g. by means of blown-in air.
The combustion or burning of the fuel essentially takes place in the fluidized bed during heating by means of the carrying medium.
The heat quantity given off to the air and the exhaust gases is conducted away with the air/exhaust gased by way of an exhaust outlet and may be utilizedforthe operation of steam boilers etc. Further, it is known to arrange heat exchanger tubes in the lower part of the combustion chamber, which tubes are surrounded by said heated carrying medium, whereby this medium gives off its heat to the tubes.
During operation said heat exchanger tubes become very warm and in this condition they are infiuenced mechanically by the whirling sand, which results in a very short lifetime for the tubes.
Further, the exhaust gases of such an incinerator are also very warm and necessitate relatively large boilers for utilization of the heat content of the exhaust gases.
The object of the invention is to provide a method and an apparatus whereby the above mentioned drawbacks to a great extent are eliminated as a result of the fact that the temperature of the fluidized bed may be held at a suitable value and further the temperature in the zone above the fluidized bed and thus the exhaust gas temperature may be reduced.
According to the invention the above mentioned object is achieved by the method set forth above in that a portion of the fluidized-bed medium is caused to pass a heat exchanger during tapping from the combustion chamber, and after cooling in the heat exchanger is returned to the fluidized bed of the combustion chamber.
For carrying out the method according to the invention there is provided an apparatus of the type set forth above which, according to the invention, is characterized in that it comprises a means for tapping of fluidized-bed medium from the combustion chamber, a heat exchanger arranged to be supplied with fluidized-bed medium during tapping from the combustion chamber, and a means for transferring medium from the heat exchanger to the combustion chamber.
By means of the present method, wherein warm fluidized-bed medium is cooled in a separate heat exchanger and is thereafter conveyed back to the fluidized bed in the combustion chamber, the bed temperature may be held down at a suitable value. The tapping or discharge of the medium may advantageously be controlled by means of a thermostat, so that the fluidized bed may be kept at a predetermined, appropriate temperature. When the fluidized bed medium (usually sand) is returned to an upper portion of the combustion chamber, this contributes to lowering the temperature in the zone above the fluidized bed. The sand is heated and the bed is supplied with heat from the sand falling down through the hot exhaust or waste gases from the combustion.The point of introducing the sand into the combustion chamber may be placed where it is found to be most suitable with respect to the fuel in question.
The invention will be more closely described below in connection with exemplary embodiments with reference to the accompanying drawing, wherein Fig. 1 shows a schematical longitudinal section of a fluidized-bed incinerator with a heat exhanger arranged externally thereto; and Fig. 2 shows a similar schematic longitudinal section with an alternative heat exchanger arrangement.
The fluidized-bed incinerator shown in Fig. 1 comprises a reactor or combustion chamber 1 which is partly filled with a granular (or the like) medium 2, e.g. sand. Air is supplied through an inlet 3 to an air box 4 arranged beneath the combustion chamber 1 of the furnace and having a roof 5 in the form of a so-called "nozzle plate" forming the bottom of the combustion chamber 1 and being provided with perforations, so that the supplied air is blown upwards into the combustion chamber 1 through said perforations and fluidizes the sand.
Fuel is supplied to the fumace by way of a suitable feeding means 6, e.g. a worm conveyor, which debouches into the combustion chamber 1 of the furnace at some distance from and above the perforated bottom plate 5.
From a point above and in the vincinity of the bottom plate 5 a conduit or channel 7 extends from the fluidized bed 2 to a separate heat exchanger 8 arranged externally to the furnace itself. In the conduit 7 heated sand may flow from the fluisized bed 2 to the associated part of the heat exchanger 7. The heat exchanger comprises a cooler portion comprising e.g. a suitable cooling tube arrangement, and a schematically shown inlet with a pump 9 for cooling medium, and further an outlet 10 for the cooling medium.
The conduit 7 may be oblique, inclined towards the heat exchanger, so that the discharged sand flows towards the heat exchanger as a result of its weight.
As shown, the conduit 7 is provided with a valve 11 which is e.g. controlled by means of a thermostat (not shown) and may control the sand quantity supplied to the heat exchanger 8. The sensor of the thermostat may e.g. sense the temperature existing in the fluidized bed, and the valve may be so arranged that it operns when the temperature increases.
After having given off a part of its heat quantity in the heat exchanger 8, the sand is conveyed therefrom by way of a transfer conduit 12 and supplied to the combustion chamber 1 through a suitable sand distributor 1 3 at the upper portion of the chamber, whereby the cooled sand cools the discharging waste gases and is again fluidized.
The cooled sand may alternatively or partly be returned directly to the fluidized bed to cool this.
The exhaust or waste gases are conducted away from the combustion chamber through an outlet 14 which may e.g. lead to a boiler (not shown). Possible secondary air for the combustion is supplied through supply means suggested schematically at 1 5.
In Fig. 2 there is shown an alternative arrangement of the apparatus according to the invention wherein a heat exchanger 1 6 is arranged in a lower part of the fluidized bed 2 in the reactor or combustion chamber 1 , and a tapping means 17 is arranged below the heat exchanger, so that fluidized-bed medium which is tapped from the reactor, passes the heat exchanger on its way to the tapping means. In this embodiment the fluidized-bed medium is thus tapped in cooled condition, whereas in the embodiment according to Fig. 1, it is tapped in hot condition. The heat exchanger may consist of a suitable tube arrangement, or e.g. of a plurality of vertically disposed, plate-shaped cooler elements.
The fluidizing air is supplied through one or more supply tubes 1 9 which are connected to upwards perforated fluidizing tubes 20 suitably distributed in the fluidized bed 2. Thus, in this case the fluidized bed comprises a fluidized zone above the fluidizing tubes 20, in which zone also the combustion of the supplied fuel takes place, and a lower non-fluidized zone below the fluidizing tubes in the region of the heat exchanger 16.
By tapping of fluidized-bed medium (sand) through the tapping means 17, sand is removed from the region around the heat exchanger, and the tapped-out sand quantity is compensated by sand falling down between the fluidizing tubes 20.
The hot sand sweeps along the surfaces of the heat exchanger elements 1 8 before it arrives at the tapping means 17, and is then relatively cold.
The transport of sand back to the combustion chamber 1 takes place through a transfer conduit 12, in a manner corresponding to that of the embodiment according to Fig. 1.
It will be seen that the operation of the apparatus according to Fig. 2 is in the fundamental principle the same as that of the embodiment according to Fig. 1, and corresponding members are designated by the same reference numerals. A repeated description of these members is therefore unnecessary.

Claims (10)

1. A method of operating a fluidized-bed incinerator having a combustion chamber containing a fluidized-bed medium which is heated during combustion of fuel in the combustion chamber, characterized in that a portion of the fluidized-bed medium is caused to pass a heat exchanger during tapping from the combustion chamber, and after cooling in the heat exchanger is retumed to the fluidized bed of the combustion chamber.
2. A method acording to claim 1, characterized in that the cooled medium is returned to the combustion chamber in an upper portion thereof and is alíowed to fall down during cooling of the zone above the fluidized bed at the same time as the medium is heated by waste gases from the combustion.
3. A method according to claim 1 or 2, characterized in that the tapping is controlled by a thermostat sensing the temperature existing in the fluidized bed.
4. Apparatus for the operation of a fluidizedbed incinerator in accordance with the method according to claim 1 , wherein the fluidized-bed iricinerator comprises a combustion chamber with a fluidized-bed medium contained therein, characterized in that it comprises a means (7; 1 7) for tapping of fluidized-bed medium from the combustion chamber (1), a heat exchanger (8; 16) arranged to be supplied with fluidized bed medium during tapping from the combustion chamber, and a means (12; 17,12) for transferring medium from the heat exchanger (8; 16) to the combustion chamber (1).
5. Apparatus according to claim 4, characterized in that the heat exchanger (8) is arranged outside the combustion chamber (1) and is connected to the fluidized bed of the combustion chamber through a channel (7) for transferring fluidized-bed medium from the fluidized bed (2) to the heat exchanger (8).
6. Apparatus according to claim 4, characterized in that the heat exchanger (1 6) is arranged in a lower portion of the fluidized bed (2) and the tapping means (17) is arranged below the heat exchanger, so that fluidized-bed medium which is tapped out, passes the heat exchanger elements (18).
7. Apparatus according to any of the claims 4-6, characterized in that the means (12, 13) for transferring medium which has been cooled in the heat exhchanger (8; 16), debouches in an upper portion of the combustion chamber (1).
8. Apparatus according to any of the claims 4-7, characterized in that the tapping means (7; 17) comprises a valve (11) which is arranged to be controlled by a thermostat sensing the temperature existing in the fluidized bed (2).
9. A method of operating a fluidised-bed incinerator having 3 combustion chamber containing a fluidised-bed medium which is heated during combustion of fuel in the combustion chamber substantially as hereinbefore described.
10. An apparatusforthe operation of a fluidisedbed incinerator substantially as hereinbefore described with reference to the accompanying drawings.
GB7930321A 1978-09-04 1979-08-31 Fluidised bed incinerator Expired GB2030275B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NO783018A NO783018L (en) 1978-09-04 1978-09-04 Fluidised bed incinerator.

Publications (2)

Publication Number Publication Date
GB2030275A true GB2030275A (en) 1980-04-02
GB2030275B GB2030275B (en) 1983-05-25

Family

ID=19884405

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7930321A Expired GB2030275B (en) 1978-09-04 1979-08-31 Fluidised bed incinerator

Country Status (5)

Country Link
DE (2) DE2935542A1 (en)
FR (1) FR2434999A1 (en)
GB (1) GB2030275B (en)
NO (1) NO783018L (en)
SE (2) SE435545B (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0093063A1 (en) * 1982-04-28 1983-11-02 Creusot-Loire Process and device for controlling the temperature of a reaction carried out in a fluidized bed
GB2121311A (en) * 1979-01-10 1983-12-21 Foster Wheeler Energy Corp Fluidized bed apparatus with particle/gas separation
GB2151503A (en) * 1981-12-15 1985-07-24 William Benedict Johnson Fluidized bed combustion apparatus and method of carrying out fluidized bed combustion
FR2598203A1 (en) * 1986-05-02 1987-11-06 Santo As METHOD FOR OPERATING AN INCINERATION PLANT AND PLANT FOR IMPLEMENTING THE METHOD
FR2693729A1 (en) * 1992-07-16 1994-01-21 Bp Chemicals Snc Gas phase polymerisation in fluidised bed reactor

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3115236A1 (en) * 1981-04-15 1982-11-04 Babcock-BSH AG vormals Büttner-Schilde-Haas AG, 4150 Krefeld Fluid bed firing
IT1155658B (en) * 1982-03-23 1987-01-28 Fata Ind Spa SYSTEM AND METHOD FOR THE RECOVERY OF SANDS CONTAINED IN FOUNDRY SHAPES AND SOULS BY CALCINATION IN A FLUIDIZED BED OVEN
DE3320049C2 (en) * 1983-06-03 1987-01-08 Inter Power Technologie GmbH, 6600 Saarbrücken Fluidized bed combustion plant
DE3347023A1 (en) * 1983-12-24 1985-07-25 Hölter, Heinz, Dipl.-Ing., 4390 Gladbeck Fluidised bed technology for small heating outputs
SE450164B (en) * 1985-10-22 1987-06-09 Asea Stal Ab SETTING TO ADJUST THE BED HEIGHT IN A POWER PLANT WITH A FLUIDIZED BED AND POWER PLANT WITH A CONTROL FOR THE BED HEIGHT
SE457015B (en) * 1987-03-25 1988-11-21 Abb Stal Ab POWER PLANT WITH FLUIDIZED BOTTOM PREPARATION
SE457014B (en) * 1987-03-25 1988-11-21 Abb Stal Ab PROVIDED TO IMPROVE THE USE OF SULFUR ABSORBENT IN PRE-BURNING IN A FLUIDIZED BATH AND A POWER PLANT WITH FLUIDIZED BOTH PREPARATION

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2624302C2 (en) * 1976-05-31 1987-04-23 Metallgesellschaft Ag, 6000 Frankfurt Methods for carrying out exothermic processes

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2121311A (en) * 1979-01-10 1983-12-21 Foster Wheeler Energy Corp Fluidized bed apparatus with particle/gas separation
GB2151503A (en) * 1981-12-15 1985-07-24 William Benedict Johnson Fluidized bed combustion apparatus and method of carrying out fluidized bed combustion
EP0093063A1 (en) * 1982-04-28 1983-11-02 Creusot-Loire Process and device for controlling the temperature of a reaction carried out in a fluidized bed
FR2526182A1 (en) * 1982-04-28 1983-11-04 Creusot Loire METHOD AND DEVICE FOR CONTROLLING THE TEMPERATURE OF A FLUIDIZED BED
FR2598203A1 (en) * 1986-05-02 1987-11-06 Santo As METHOD FOR OPERATING AN INCINERATION PLANT AND PLANT FOR IMPLEMENTING THE METHOD
FR2693729A1 (en) * 1992-07-16 1994-01-21 Bp Chemicals Snc Gas phase polymerisation in fluidised bed reactor

Also Published As

Publication number Publication date
FR2434999B1 (en) 1984-12-14
GB2030275B (en) 1983-05-25
DE2935520A1 (en) 1980-03-13
DE2935542A1 (en) 1980-03-27
SE7907227L (en) 1980-03-05
NO783018L (en) 1980-03-05
SE7907226L (en) 1980-03-05
SE435545B (en) 1984-10-01
FR2434999A1 (en) 1980-03-28

Similar Documents

Publication Publication Date Title
US4279222A (en) Feed of material to fluidized beds
EP0006307B1 (en) Boiler
US3921590A (en) Fluidised bed incinerators
US4227488A (en) Fluidized bed unit including a cooling device for bed material
EP0005964B1 (en) Boiler and combustion means therefor
US4349969A (en) Fluidized bed reactor utilizing zonal fluidization and anti-mounding pipes
GB2030275A (en) Fluidized bed incinerator
JPS6217123B2 (en)
PL200942B1 (en) Circulation-type fluidised-bed reactor with a controllable internal heat exchanger
JPH0650678A (en) Fluidized-bed reactor device and method having heat exchanger
US4499857A (en) Fluidized bed fuel burning
EP0073650B1 (en) Fluidized bed heat exchanger
US4279205A (en) Storage
US4574743A (en) Heat generator for heating a fluid by heat exchange through a fluidized bed and a process for implementing same
US4454838A (en) Steam generator having a circulating fluidized bed and a dense pack heat exchanger for cooling the recirculated solid materials
US4436507A (en) Fluidized bed reactor utilizing zonal fluidization and anti-mounding air distributors
US3877397A (en) Incinerators
US4510892A (en) Seal for boiler water wall
US5308585A (en) Process and apparatus for cooling hot solids coming from a fluidized bed reactor
US4521976A (en) Method of operating a fluidized bed heat exchanger utilizing induced circulation
US2276659A (en) Wet refuse furnace and system
GB2080138A (en) Fluidizable bed combustion chamber with ash-discharging means
US4388066A (en) Radiation shield and method of use
EP0981018A1 (en) Fluidized bed combustion boiler
JPH01203801A (en) Fluidized bed boiler having vertical heat transfer pipe and fluidized bed hot water boiler employing said boiler

Legal Events

Date Code Title Description
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
PCNP Patent ceased through non-payment of renewal fee

Effective date: 19920831