EP0141890A1 - Verfahren und Vorrichtung zum Umwälzen von Abgasen in einer Sinteranlage - Google Patents

Verfahren und Vorrichtung zum Umwälzen von Abgasen in einer Sinteranlage Download PDF

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Publication number
EP0141890A1
EP0141890A1 EP83402210A EP83402210A EP0141890A1 EP 0141890 A1 EP0141890 A1 EP 0141890A1 EP 83402210 A EP83402210 A EP 83402210A EP 83402210 A EP83402210 A EP 83402210A EP 0141890 A1 EP0141890 A1 EP 0141890A1
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EP
European Patent Office
Prior art keywords
heat
zone
waste gases
waste
sintering
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
EP83402210A
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English (en)
French (fr)
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EP0141890B1 (de
Inventor
Takashi Futakuchi
Kiyofumi Nakamura
Yoshimasa Sato
Toshio Tsukuda
Hiroyuki Shiraishi
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.)
Sumitomo Heavy Industries Ltd
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Sumitomo Heavy Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by Sumitomo Heavy Industries Ltd filed Critical Sumitomo Heavy Industries Ltd
Priority to DE8383402210T priority Critical patent/DE3371412D1/de
Priority to EP19830402210 priority patent/EP0141890B1/de
Publication of EP0141890A1 publication Critical patent/EP0141890A1/de
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Publication of EP0141890B1 publication Critical patent/EP0141890B1/de
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B1/00—Preliminary treatment of ores or scrap
    • C22B1/14—Agglomerating; Briquetting; Binding; Granulating
    • C22B1/16—Sintering; Agglomerating
    • C22B1/20—Sintering; Agglomerating in sintering machines with movable grates
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B21/00—Open or uncovered sintering apparatus; Other heat-treatment apparatus of like construction
    • F27B21/06—Endless-strand sintering machines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D17/00—Arrangements for using waste heat; Arrangements for using, or disposing of, waste gases
    • F27D17/004—Systems for reclaiming waste heat

Definitions

  • the present invention relates generally to an on-strand type sintering apparatus having a sintering zone and a cooling zone extending along a horizontal strand and, more particularly, to both a waste gas circulation method and a waste gas circulation system for heat recovery of the on-strand type sintering apparatus.
  • the sintering apparatus existing in the art is generally divided into two types, namely, a separate type, in which a sintering machine and a cooling machine are so separately arranged that the sintered ore product discharged from the former is introduced into and cooled by the latter after it has been crushed, and an on-strand type in which a sintering zone and a cooling zone immediately following the former zone are formed to extend along a horizontal strand.
  • the water has to be preheated in case the waste gases coming from the intermediate and downstream portions of the sintering machine are to be subjected to a heat exchanging process. This is because those waste gases contain such a considerable amount of SO x that condensation of sulfuric acid is undesirably invited.
  • the heat recovery is conducted only from the waste gases coming from the cooling zone while allowing the sensible heat of the hot waste gases to uselessly dissipate into the atmosphere.
  • the waste gases coming from the cooling zone is so sufficiently hot as to permit the heat recovery therefrom. This is because the sinter in the cooling zone shrinks to generate fine cracks all over the secion of the cooling zone so that its effective surface area to be cooled can be so increased as to reduce the flow rate of the cooling air and to shorten the cooling time period.
  • an object of the present invention to provide a waste gas circulation method for effectively recovering the heat which might otherwise be released from an on-strand type sintering apparatus having its sintering and cooling zones extending continuously along a horizontal strand.
  • Another object of the present invention is to provide a waste gas circulation system for putting the above-specified method into practice by repeatedly circulating the waste gases through a charge mixture of ore, solid fuel and flux being sintered and through the sintered ore product thereby to effectively recover the heat which might otherwise be carried away by the waste gases discharged.
  • the present invention is based upon the aforementioned differences between the separate type and on-strand type sintering apparatus and has been conceived in view of the facts that the waste gases discharged from the sintering apparatus take their maximum temperature at a point where the sintering reaction is completed in the actual run of the sintering apparatus, namely, where the cooling operation is started, and that the point and its neighborhood act as an important zone for recovering that sensible heat.
  • the gist of the present invention resides in that the hottest waste gases arising at the final stage of the sintering zone and at the front stage of the cooling zone, in which the sintering reaction is completed, are subjected to heat recovery, and in that the problem, which naturally takes place in the case of the heat recovery, namely, the condensation of sulfur oxides SO x of the waste gases in the form of droplets of sulfuric acid is prevented by preheating the water, which is supplied for the purpose of that heat recovery, with the waste gases coming from the downstream half of the cooling zone.
  • a waste gas circulation method for heat recovery of on-strand type sintering apparatus which includes: a sintering zone having a plurality of wind boxes; and a cooling zone extending just downstream of said sintering zone and having a plurality of wind boxes, comprising: a first step of exchanging the heat of still hot waste gases coming from the wind boxes belonging to both the intermediate stage and at least a portion of the final stage of said cooling zone with cold water to recover said heat thereby to heat said cold water into hot water; and a second step of exchanging the heat of the hot waste gases coming directly from the wind boxes belonging to a mixed zone consisting of the final stage of said sintering zone and the front stage of said cooling zone with the hot water, which has been heated at the first-named heat exchanging step,to recover the second-named heat thereby to heat said hot water into steam, whereby the heat generated by the sintering action of a charge mixture of ore, solid fuel and flux can be efficiently recovered as said steam
  • the second heat exchanging step comprises; a first sub-step of exchanging the heat of the hottest waste gases coming directly from the wind boxes (16 3 ) belonging to a mixed zone consisting of the final stage of said sintering zone and the front stage of said cooling zone with steam to recover the second-named heat thereby to heat said steam into superheated steam, and a second sub-step of exchanging the heat of the waste gases, which have been subjected to the first heat exchanging sub-step, with the hot water, which has been heated at the first heat exchanging step, thereby to heat said hot water into the steam which is to be heated at the first heat exchanging sub-step.
  • a waste gas circulation system for heat recovery of on-strand type sintering apparatus which includes: a sintering strand arranged generally in a horizontal direction; conveying means for conveying a charge mixture of ore, solid fuel and flux along said sintering strand; feeding means for feeding said conveying means with said charge mixture; ignition means for igniting the solid fuel in said charge mixture at the surface thereof so that the sintering of said charge mixture may be started; and a plurality of wind boxes arranged on line below and opened toward said charge mixture through the pallets of said sintering strand, said wind boxes being so grouped as to belong to an ignition zone, which underlies said ignition means, a sintering zone, in which the sintering reaction of said charge mixture proceeds until it is completed, and a cooling zone in which a sintered ore product resulting from said sintering reaction is cooled down, comprising: first heat exchanging means for exchanging the heat of still hot waste gases coming from the wind
  • reference numeral 10 Indicated at reference numeral 11 is a sintering strand which is arranged to extend in a horizontal direction.
  • the sintering strand 11 supports a plurality of not-shown pallets which are driven to travel in series therealong so that they are successively fed with a hearth layer and a charge mixture of ore, solid fuel and flux from a hearth layer hopper 12 and a mixture surge hopper 13, respectively.
  • the charge mixture is ignited at its surface by the action of an ignition furnace 14 so that the sintering reaction of the charge mixture may be started.
  • the suction system 17 is composed of a corresponding number of branch ducts or downcomers 17 1 , which are respectively connected with the wind boxes 16 (i.e., Nos.
  • the downcomers 17 1 are respectively equipped with valves 17 3 for controlling the respective flow rates of the waste gases therethrough.
  • the waste gases thus cleared of the dust and the SO x and NO X are discharged from the collector main 17 2 to the atmosphere by way of a stack 19.
  • the pallets are driven to travel on rails 21, which are mounted on the sintered strand 11, by the rotations of a charge side sprocket 22 and a discharge side sprocket 23.
  • the charge mixture is ignited at its surface by the action of the ignition furnace 14.
  • the solid fuel in the charge mixture thus ignited sinters the ore more deeply into the charge mixture as this mixture is conveyed from the feed end to the discharge end.
  • the resultant sinter or the sintered ore product is crushed by means of a crusher 24.
  • the crushed sinter is fed to a not-shown cooling machine in which it is cooled down. In this meanwhile, dust resulting from the crushing operation is so much that it has to be carried by suction to a not-shown dust collector (which may be of electrostatic type).
  • FIG. 2 an on-strand type sintering apparatus, which is indicated generally at reference numeral 20 and which is equipped with a waste gas circulation system 30 according to the present invention, will be described.
  • like reference numerals indicate like or corresponding parts of the sintering apparatus 10 of the prior art shown in Fig. 1.
  • wind boxes are divided into a first group of wind boxes 16 1 (which are numbered at 1 to 6), a second group of wind boxes 16 2 (which are numbered at 7 to 11), a third group of wind boxes 16 3 (which are numbered at 12 to 16), and a fourth group of wind boxes 16 4 (which are numbered at 17 to 20).
  • the first group wind boxes 16 1 are further grouped into the wind boxes Nos. 1 and 2, which belong to the ignition zone underlying the ignition furnace 14, and into the wind boxes Nos. 3 to 6, which belong to the front stage of the sintering zone where the sintering reaction of the charge mixture proceeds.
  • the second group wind boxes Nos. 7 to 11 belong to the intermediate stage of the sintering zone where that sintering reaction further proceeds.
  • the third group wind boxes Nos. 12 to 16 belong to the final stage of the sintering zone, where that sintering reaction is completed, and to the front stage of a cooling zone where the sintered ore product is cooled down.
  • the fourth group wind boxes Nos. 17. to 20 belong to the intermediate and final stages of the cooling zone where the sinter or sintered ore product is sufficiently cooled down for the subsequent crushing operation resorting to a crusher 24'.
  • the first group wind boxes 16 1 i.e., Nos. 1 to 6, are connected with the stack 19 through an electrostatic precipitator 18 1 and a blower 15 1 by way of the downcomers 17 11 and the collector main 17 21 .
  • the second group wind boxes 16 2 i.e., Nos. 7 to 11, are made to merge into the collector main 17 21 through a desulfurating and denitrating device 18 2 and a blower 15 2 by way of the downcomers 17 12 and the collector main 17 22 .
  • the third group wind boxes 16g i.e., Nos.
  • the fourth group wind boxes 16 4 i.e., Nos. 17 to 20, are conneced through the downcomers 17 14 and the collector main 17 24 with a waste-heat boiler 27 so that the waste gases may be circulated, after they have exchanged their heat with the water flowing through a water pipe, to a mixed zone hood 28 by the action of a blower 15 4 .
  • reference numeral 29 indicates a fresh air guide hood which extends above the pallets travelling over the wind boxes Nos. 17 to 20 of the intermediate and final stages of the cooling zone and above the discharge end of the sintering apparatus 20 for guiding fresh air into the sinter. Since the fresh air guide hood 29 forms such a compartment as is opened toward the discharge end for allowing the dust, which might otherwise drop down to the outside, to be returned together with the fresh air to the particular sinter.
  • Pure water is supplied from the outside to flow through the water pipe of the waste-heat boiler 27 until the resultant hot water flows into a steam drum 31, as better seen from Fig. 3.
  • the hot water reserved in the lower portion of the steam drum 31 is pumped out by the action of a pump 32 to the evaporator portion 25 2 of the waste-heat boiler 25 so that it is heated into steam, which is to be returned to the steam drum 31.
  • the steam thus reserved in the upper portion of the steam drum 31 is guided through the superheater portion 25 1 of the waste-heat boiler 25, in which it is heated into superheated steam.
  • This superheated steam is then discharged to the outside so that its energy may be recovered as an electric power by driving a steam turbine or the like.
  • refernece numerals 33 1 and 33 2 indicate dampers which are connected, respectively, between the downcomers 17 11 and 17 12 leading from the wind boxes 16 1 and 16 2 of the front and intermediate stages of the sintering zone and between the downcomers 17 12 and 17 13 leading from the wind boxes 16 2 of the intermediate stage of the sintering zone and the wind boxes 16 3 of the mixed zone.
  • the dampers 33 1 and 33 2 thus connected are adjusted so as to obtain a smooth sloping variation in the pressure difference at each boundary portion between the adjacent groups of wind boxes.
  • Fig. 4 there is shown another embodiment of the present invention, in which the water pipe of the waste-heat boiler 27 is also divided into two portions, i.e., an evaporator portion 27 1 and an economizer portion 27 2 both connected with the steam drum 31.
  • the remaining construction is absolutely the same as the first embodiment shown in Fig. 3, and the description to be made in the following is accordingly directed only to the different portion of the construction.
  • the pure water is supplied at a flow rate, which corresponds to the steam generation rate of the waste-heat boilers 25 and 27, first to the economizer portion 27 2 of the waste-heat boiler 27, in which it is preheated until it flows into the steam drum 31.
  • the hot water reserved in the lower portion of the steam drum 31 is pumped out by the actions of the pumps 32 and 32 1 , respectively, to the evaporator portions 25 2 and 27 1 of the waste-heat boilers 25 and 27, in which it is heated until it is returned to the steam drum 31.
  • the steam thus separated by the steam drum 31 is then introduced into the highest-temperature portion or the superheater portion 25 1 of the water pipe of the waste-heat boiler 25 until it is discharged as the superheated steam to the outside of the heat exchanging system under discussion.
  • Fig. 5 illustrates the sintering zone temperature distribution and the NO x and SO x concentration patterns along the strand in accordance with the present Example .
  • the point at which the sintering reaction is completed is located at the wind box No. 14. More specifically, the instant when the temperatures A of the waste gases reach their maximum in an actual running operation is found to occur approximately three minutes after the temperature of the combustion zone of the lowermost layer has reached the maximum temperature. That instant is referred to as the "Burn Through Point" which is indicated at reference letters BTP.
  • BTP the mixed zone extending from the wind box No. 12 to the wind box No.
  • the waste gases in that mixed zone which consists of the final stage of the sintering zone and the front state of the cooling zone, still has an oxygen concentration as high as 19 to 20 % and a moisture content as low as 1.0 to 1.5 % so that the particular waste gases can be advantageously reused as the burning air.
  • this reuse is conducted for the wind boxes Nos. 3 to 11, which belong to the front and intermediate stages of the sintering 'zone, so that generation of NO x can be restricted to 15 to 20 %.
  • reference letter C appearing in Fig. 5 indicates the high-temperature zone at 1200 O C or higher, namely, the combustion zone where the charge mixture is being burned.
  • the high-temperature combustion zone C reaches the lowermost surface at the end of the second group wind boxes 16 2 .
  • the sintering reaction at this point is not completed yet, as has been touched in the above, so that the SO x is still generated at such a considerable rate as will invite the mixing of the SO x with the waste gases coming from the third group wind boxes 16 3 belonging to the mixed zone. Therefore, one might deduce that sulfuric acid would condense in the form of droplets on the water pipes of the waste-heat boiler 25 and would cause corrosion of the evaporator and superheating pipes.
  • the pure water has already been heated in the waste-heat boiler 27 so that at least the warm water will flow through those pipes of the waste-heat boiler 25, there is no danger of the pipe corrosion due to the condensation of sulfuric acid.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Environmental & Geological Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Manufacturing & Machinery (AREA)
  • Geology (AREA)
  • Materials Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Manufacture And Refinement Of Metals (AREA)
EP19830402210 1983-11-16 1983-11-16 Verfahren und Vorrichtung zum Umwälzen von Abgasen in einer Sinteranlage Expired EP0141890B1 (de)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE8383402210T DE3371412D1 (en) 1983-11-16 1983-11-16 Waste gas circulation method and system for sintering apparatus
EP19830402210 EP0141890B1 (de) 1983-11-16 1983-11-16 Verfahren und Vorrichtung zum Umwälzen von Abgasen in einer Sinteranlage

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP19830402210 EP0141890B1 (de) 1983-11-16 1983-11-16 Verfahren und Vorrichtung zum Umwälzen von Abgasen in einer Sinteranlage

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EP0141890A1 true EP0141890A1 (de) 1985-05-22
EP0141890B1 EP0141890B1 (de) 1987-05-06

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0302120A1 (de) * 1987-02-16 1989-02-08 Sumitomo Heavy Industries, Ltd Vorrichtung zur wärmegewinnung beim sintern
CN106370019B (zh) * 2016-11-24 2018-07-03 山东钢铁股份有限公司 一种烧结烟气捕集装置及方法
CN114485178A (zh) * 2022-01-11 2022-05-13 北京科技大学 一种多工序协同利用余热的烧结料层干燥系统

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2297922A1 (fr) * 1975-01-15 1976-08-13 Siderurgie Fse Inst Rech Procede et dispositif de prechauffage du melange d'agglomeration
AT352408B (de) * 1978-03-24 1979-09-25 Voest Ag Verfahren zum brennen von pellets auf einem wanderrost
FR2444720A1 (fr) * 1978-12-22 1980-07-18 Delattre Levivier Procede d'utilisation des gaz aspires dans une installation d'agglomeration de minerais et installation d'agglomeration perfectionnee
US4371150A (en) * 1979-11-02 1983-02-01 Sumitomo Heavy Industries, Inc. Sintering plant

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2297922A1 (fr) * 1975-01-15 1976-08-13 Siderurgie Fse Inst Rech Procede et dispositif de prechauffage du melange d'agglomeration
AT352408B (de) * 1978-03-24 1979-09-25 Voest Ag Verfahren zum brennen von pellets auf einem wanderrost
FR2444720A1 (fr) * 1978-12-22 1980-07-18 Delattre Levivier Procede d'utilisation des gaz aspires dans une installation d'agglomeration de minerais et installation d'agglomeration perfectionnee
US4371150A (en) * 1979-11-02 1983-02-01 Sumitomo Heavy Industries, Inc. Sintering plant

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0302120A1 (de) * 1987-02-16 1989-02-08 Sumitomo Heavy Industries, Ltd Vorrichtung zur wärmegewinnung beim sintern
EP0302120A4 (en) * 1987-02-16 1991-07-10 Sumitomo Heavy Industries, Ltd Apparatus for recovering waste heat of sintering
CN106370019B (zh) * 2016-11-24 2018-07-03 山东钢铁股份有限公司 一种烧结烟气捕集装置及方法
CN114485178A (zh) * 2022-01-11 2022-05-13 北京科技大学 一种多工序协同利用余热的烧结料层干燥系统
CN114485178B (zh) * 2022-01-11 2022-12-20 北京科技大学 一种多工序协同利用余热的烧结料层干燥系统

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Publication number Publication date
EP0141890B1 (de) 1987-05-06
DE3371412D1 (en) 1987-06-11

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