US3891383A - Rotary kiln apparatus with suspension preheater having burner for calcining - Google Patents

Rotary kiln apparatus with suspension preheater having burner for calcining Download PDF

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Publication number
US3891383A
US3891383A US421329A US42132973A US3891383A US 3891383 A US3891383 A US 3891383A US 421329 A US421329 A US 421329A US 42132973 A US42132973 A US 42132973A US 3891383 A US3891383 A US 3891383A
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United States
Prior art keywords
clinker
rotary kiln
cooler
precooler
grate
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Expired - Lifetime
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US421329A
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English (en)
Inventor
Toshihiro Kobayashi
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IHI Corp
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IHI Corp
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    • 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
    • F27B7/00—Rotary-drum furnaces, i.e. horizontal or slightly inclined
    • F27B7/20—Details, accessories, or equipment peculiar to rotary-drum furnaces
    • F27B7/2016—Arrangements of preheating devices for the charge
    • F27B7/2025—Arrangements of preheating devices for the charge consisting of a single string of cyclones
    • F27B7/2033—Arrangements of preheating devices for the charge consisting of a single string of cyclones with means for precalcining the raw material
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B7/00—Hydraulic cements
    • C04B7/36—Manufacture of hydraulic cements in general
    • C04B7/43—Heat treatment, e.g. precalcining, burning, melting; Cooling
    • C04B7/47—Cooling ; Waste heat management

Definitions

  • the apparatus consists of a suspension preheater with [58] H "432/lO5 6 82 l 17 a calcining burner, a rotary kiln, a planetary type mule 432/8O 133 l5 ticylinder precooler installed into a unitary construc- 172, 5 6 tion with the rotary kiln and a main cooler and it aims to take away many problems and defects caused by the conventional system having production capacity [56] g gf il'gg gzf more than several thousand tons per day.
  • One of the objects of the present invention is therefore to provide an improved SCP kiln which may substantially eliminate the problems and defects encountered in the conventional SCP kilns.
  • FIG. 1 is a diagrammatic view partly in sectionof a conventional SCP kiln
  • FIG. 2 is a diagrammatic view, partly in section, of a rotary kiln installation in accordance with the present invention.
  • FIG. 3 is a graph illustrating the clinker cooling speeds attained by the kiln installation shown in FIGS. 1 and 2.
  • the remaining air is discharged through a vent 9 of the clinker cooler 3 to the atmosphere after it has been treated by a dust collector (not shown).
  • air velocity in the secondary air duct is generally higher than gas velocity in the kiln from the economical reasons and in addition the dust collector 81 is installed so that the secondary air flow system needs higher draft resistance than the kiln gas flow system.
  • the kiln gas flow system of the suspension preheater l is provided with an orifice 83 (a narrowed gas passage) so as to keep balance of the draft between two flow systems.
  • a fan may be installed in the secondary air duct 82 but it is not a practical method in view of its durability because a high temperature air with some clinker dust has to be handled.
  • the clinker dust caught by the collector 81 is returned to cooler 3.
  • the service life of the refractory materials can be elongated so that the apparatus may be operated continuously for a long period of time because the thermal load of the rotary kiln may be considerably reduced due to the effects of the calcining burner in the preheater as compared with the conventional SP kilns.
  • the thermal load of the rotary kiln may be considerably reduced due to the effects of the calcining burner in the preheater as compared with the conventional SP kilns.
  • the grate type clinker cooler of a large size unit the impact of clinker being dropped from the rotary kiln and the thermal load are increased. Therefore the wear and abrasion of the grate at the high temperature portion thereof are remarkably increased.
  • the width of the grate cannot be increased in proportion to the capacity of the rotary kiln because if it is increased the formation of clinker bed the grate is adversely affected.
  • the speed of the grate cannot be also increased in proportion to the capacity because the abrasion and wear of the grate are much enhanced.
  • the thickness of the clinker layer upon the grate must be increased gradually according to the enlargement of the size of the apparatus so that the power consumption of the blower for cooling air is increased due to a pressure loss of thicker clinker layer or bed.
  • a planetary type multicylinder cooler is of greater advantage to the durability, but all air which is used for cooling the clinker must be induced into a kiln from the construction view point so that it is not applicable for the SCP apparatus of the type described hereinbefore. Furthermore a planetary type multicylinder cooler is inferior in rapid and complete cooling effects of clinker to a grate type cooler. Moreover in the conventional SCP apparatus the orifice must be installed in the kiln gas flow system as described herein before so as to keep balance of the draft between two flow systems and it is indispensable that the power consumption of the apparatus is increased regardless of the orifice.
  • the primary object of the present invention is to provide a SCP apparatus with a cooler which may substantially eliminate the problems and defects encountered in the conventional apparatus and which may serve to increase the capacity of the apparatus and to decrease the height thereof.
  • the apparatus of the present invention is characterized by a planetary type multicylinder precooler assembled into a unitary construction with a rotary kiln so that combustion air required by a kiln burner is induced through the cylinders of said precooler and that when the cylinders of said precooler pass the heighest point, clinker in the cylinders is discharged to a main cooler.
  • an inclined surface for charging clinker and/or a clinker pocket between the precooler and the hot end of the main cooler is interposed an inclined surface for charging clinker and/or a clinker pocket, and the rotary kiln and the main cooler are disposed horizontally and in series.
  • the apparatus of the present invention shown in FIG. 2 is similar to the conventional apparatus shown in FIG. 1 except that high temperature clinker is cooled by a planetary type multicylinder precooler 31 assembled into a unitary construction with the rotary kiln 2 and a main cooler 32 joined to the planetary type multicylinder precooler 31.
  • Combustion air of ambient tempera ture and of the quantity required for the combustion of a rotary kiln burner 4 is induced through the cylinders 'of the planetary type multicylinder precooler 31 so that high temperature clinker in each cylinder is rapidly cooled or quenched before it is discharged into the main cooler 32.
  • main cooler 32 which is of the grate type, clinker is completely cooled, and preheated air of the quantity required for the combustion ofa calcining burner 5 is induced through the dust collector 81 and the secondary air duct 82 into the suspension preheater 1 so as to improve its thermal efficiency.
  • preheated air of the quantity required for the combustion ofa calcining burner 5 is induced through the dust collector 81 and the secondary air duct 82 into the suspension preheater 1 so as to improve its thermal efficiency.
  • the remaining air is discharged to the atmosphere through the vent 9 and the dust collector (not shown).
  • clinker may be cooled to 900C before it was discharged into the main cooler 32, whereas combustion air preheated to about 900C may be induced into the rotary kiln 2.
  • Clinker discharged into the grate type main cooler 32 from the precooler 31 may be cooled completely to about 60C by cooling air of ambient temperature supplied at a rate of about 2.4 Nm lkg of clinker, whereas combustion air preheated to about 600C may be induced through the second air duct 82 into the suspension preheater 1 at a rate of 0.6 Nm' /kg of clinker, and the remaining air of about 190C may be discharged through the vent 9 at a rate of 1.8 Nm /kg of clinker.
  • high temperature clinker is rapidly cooled in the planetary type multicylinder precooler along the cooling curve c between the points A and B in FIG. 3 so that the discharged clinker may be cooled to 900C.
  • combustion air for a kiln burner may be preheated along the curve e. Therefore it is seen that the rapid coding efficiency of the planetary type multicylinder precooler of the present invention is substantially similar to that of a grate cooler.
  • the clinker charged to the main cooler is further cooled along the curve I; from the point B to the point C where temperature may be about 60C.
  • an inclined surface 10 and/or a clinker pocket 11 can be disposed at the hot end of the main cooler 32 without difficulties in order to absorb the impact of clinker charged onto the grate and at the same time to uniformly spread clinker over the whole width of the grate, thereby forming a desired bed or layer of clinker.
  • a weir 12 is disposed at the discharged end of each cylinder so that clinker in each cylinder is discharged from the precooler 31 into the main cooler 32 at the highest position of the cylinder, that is the vertex of the rotation of the cylinder, and the main cooler 32 is installed substanitally in horizontal relation with the rotary kiln 2 and the precooler 31 so that the overall height of the apparatus may be decreased by about 10m in comparison with the conventional apparatus of the-type shown in FIG. 1.
  • the average temperature difference between clinker and cooling air becomes 1.5 times and the heat capacity to be exchanged in the cooler is only about 40% because clinker is cooled from about 1,300C to about 900C by air of ambient temperature in the planetary type multicylinder precooler in accordance with the apparatus of the present invention.
  • the size of the cooler may be reduced from /3 to so that even when the capacity of the apparatus is increased the precooler may be installed in a cantilever manner upon the discharge end of an extended shell of the rotary kiln without any additional support.
  • the precooler of the present invention does not bring any additional power consumption.
  • the power consumption of the blower for cooling air in the present invention may be reduced to 1.5 KWI-I/t of clinker.
  • the sloped surface and/or the clinker pocket 11 is so arranged as to prevent the grate from being exposed to the impact of clinker and to facilitate the uniform distribution of clinker over the grate. Therefore the thickness of the clinker bed or layer will not be increased as the capacity of apparatus being enlarged. As a result the power consumption of the blower may be saved by the apparatus of the present invention as much as 2.0 KWH/t of clinker in case of the installation of a large capacity.
  • a double pass method can be applied for the main cooler as a preferred embodiment of the present invention.
  • the cooler chamber above the grate is divided into two zones, i.e. a high and a low temperature zones, and cooling air is supplied to respective zones by two independent fans. Cooling air supplied to the low temperature zone is vented from a vent port and sent to the suction side of the cooling air fan for the high temperature zone by way of a dust collector. Thus clinker of high temperature zone is cooled by vent air from the low temperature zone.
  • the double pass method By the double pass method, a heat recuperative efficiency is raised and air polusion caused by wasting vent air can be solved completely, so it had been deviced and demonstrated also by the conventional SP kilns but it was not practical because the grate at the high temperature zone had been overheated and service life of the grate had been shortened remarkably.
  • clinker which is cooled to about 900C by the precooler is supplied to the main cooler so that the grate will not be nated.
  • the double pass method of the grate type cooler or the counter flow rotary cooler is used as the preferred embodiment of the present invention the effects, herein mentioned, such as mitigation of thermal load of the main cooler, the overall height of the apparatus, etc. may be fully achieved.
  • the planetary type multicylinder precooler which is installed into a unitary construction with the rotary kiln, may rapidly cool clinker below 1000C only by air which is used as preheated combustion air for the rotary kiln.
  • the precooler is simple in construction and adapted to be used with a rotary kiln installation of a large capacity.
  • the inclined surface and/or the clinker pocket are provided at the hot end of the main cooler so as to prevent the grate from being directly exposed to the impact of clinker and also to facilitate the uniform distribution of clinker over the whole width of the grate. Furthermore the thermal load of the main cooler is reduced because of the installation of the precooler. As a result the durability of the grate type main cooler is not lowered even when the capacity of the rotary kiln installation is increased.
  • the weir is attached to the discharge end of the precooler so that clinker may be discharged into the main cooler only when each cylinder of the precooler reaches the highest position or the vertex of the rotation. Therefore the rotary kiln and the main cooler may be installed horizontally and in series so that the overall height of the rotary kiln installation of the present invention may be reduced by about 10 meters as compared with the conventional installation.
  • the precooler may be mounted upon the discharge end of the extended shell of the rotary kiln in a cantilever manner. Therefore opposed to the planetary type multicylinder cooler used in the conventional SP kilns of a large capacity it is not required to provide any support for the precooler.
  • Clinker of high temperature whose permeable resistance is high is rapidly cooled in the planetary type precooler, so that even when the grate type main cooler is employed the economy of the power consumption of 1.5 2 KWI-I/t of clinker may be attained.
  • a double pass method of the grate type cooler or a counter flow rotary cooler can be applied so as to improve the heat recuperative efficiency and to eliminate the wasting of cooler vent air.
  • the present invention may provide a SCP rotary kiln installation with precooler which may eliminate the problems and defects encountered in the conventional installations when its capacity must be increased and which may decrease the overall height thereof.
  • Apparatus of the type having a suspension preheater to which powdery raw materials are supplied and also having a calcining burner, a rotary kiln for receiving the raw materials and including a burner for burning the raw materials to cement clinker and also including a discharge end for the clinker, and a planetary type multicylinder precooler associated with said discharge end comprising a plurality of cylinders arranged in a circle concentric with the kiln, said cylinders extending parallel to the kiln longitudinal axis and having means at its outlet ends to provide direct communication'with the atmosphere and having its inlet ends communicating with said discharge end, the outlet ends of each cylinder being provided with an upstanding weir means arranged to allow discharge of clinker only when the cylinders approach the highest position of rotation and a main cooler having an inlet for receiving clinker from the outlet ends of the cylinders and a vent port connected with the calcining burner.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Ceramic Engineering (AREA)
  • Structural Engineering (AREA)
  • Thermal Sciences (AREA)
  • Materials Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Muffle Furnaces And Rotary Kilns (AREA)
  • Furnace Details (AREA)
  • Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)
  • Curing Cements, Concrete, And Artificial Stone (AREA)
US421329A 1972-12-06 1973-12-03 Rotary kiln apparatus with suspension preheater having burner for calcining Expired - Lifetime US3891383A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP47121646A JPS5249494B2 (it) 1972-12-06 1972-12-06

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US (1) US3891383A (it)
JP (1) JPS5249494B2 (it)
BR (1) BR7309562D0 (it)
CA (1) CA1003212A (it)
CH (1) CH578161A5 (it)
CS (1) CS212739B2 (it)
DE (1) DE2360580B2 (it)
DK (1) DK135869B (it)
ES (1) ES421163A1 (it)
FR (1) FR2209732B1 (it)
GB (1) GB1413055A (it)
IT (1) IT1005212B (it)
SE (1) SE406009B (it)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3975148A (en) * 1974-02-19 1976-08-17 Onoda Cement Company, Ltd. Apparatus for calcining cement
US4028049A (en) * 1974-03-29 1977-06-07 Ciments Lafarge S.A. Method and installation of treating raw material for producing cement
US4110915A (en) * 1975-12-12 1978-09-05 Fives-Cail Babcock Manufacture of cement
US4169701A (en) * 1976-11-29 1979-10-02 Mitsubishi Jukogyo Kabushiki Kaisha Fluidized-bed kiln with preheating means
US4201541A (en) * 1974-06-03 1980-05-06 Fritz Schoppe Process and installation for the production of calcined material
US4326845A (en) * 1981-01-02 1982-04-27 Allis-Chalmers Corporation Suspension preheater for cement calcining plant
US4492570A (en) * 1982-09-02 1985-01-08 Kawasaki Jukogyo Kabushiki Kaisha Calcining system provided with a planetary cooler
US4511333A (en) * 1981-12-21 1985-04-16 Klockner-Humboldt-Deutz Ag Device for burning cement
DE3517884A1 (de) * 1985-05-17 1986-11-20 Krupp Polysius Ag, 4720 Beckum Anlage zur waermebehandlung von feinkoernigem gut
DE3520927A1 (de) * 1985-06-11 1986-12-11 Krupp Polysius Ag, 4720 Beckum Vorrichtung zur waermebehandlung von feinkoernigem gut
DE19504589A1 (de) * 1995-02-11 1996-08-14 Kloeckner Humboldt Deutz Ag Rostkühler
US5562443A (en) * 1992-11-12 1996-10-08 F. L. Smidth & Co. A/S Rotatable cooler for a rotary kiln plant
US20040029064A1 (en) * 2000-08-24 2004-02-12 Skaarup Jensen Lars Jensen Method and plant for manufacturing cement clinker

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1502351A (en) * 1975-07-23 1978-03-01 Smidth & Co As F L Planetary cooler
DE2550469C2 (de) * 1975-11-10 1987-12-23 Krupp Polysius Ag, 4720 Beckum Anlage zum Brennen oder Sintern von feinkörnigem Gut
JPS5537457A (en) * 1978-09-11 1980-03-15 Babcock Hitachi Kk Cooling fired blocks

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3350077A (en) * 1965-08-05 1967-10-31 Smidth & Co As F L Rotary kiln installations
US3358977A (en) * 1965-08-05 1967-12-19 Smidth & Co As F L Rotary kiln installations
US3416778A (en) * 1966-05-06 1968-12-17 Polysius Gmbh Apparatus for thermal treatment of minerals
US3452968A (en) * 1966-10-12 1969-07-01 Ishikawajima Harima Heavy Ind Roasting process of fine ore and a device therefor
US3539164A (en) * 1967-04-22 1970-11-10 Kloeckner Humboldt Deutz Ag Cooler for hot lump goods,particularly cement clinker
US3612499A (en) * 1969-02-12 1971-10-12 Polysius Ag Apparatus for heat treatment of fine material
US3723597A (en) * 1970-01-23 1973-03-27 Fives Lille Cail Calcining phosphate minerals
US3782888A (en) * 1972-10-04 1974-01-01 Allis Chalmers Method and apparatus for heat treating with heat recuperation from material cooling and auxiliary heat during startup

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3350077A (en) * 1965-08-05 1967-10-31 Smidth & Co As F L Rotary kiln installations
US3358977A (en) * 1965-08-05 1967-12-19 Smidth & Co As F L Rotary kiln installations
US3416778A (en) * 1966-05-06 1968-12-17 Polysius Gmbh Apparatus for thermal treatment of minerals
US3452968A (en) * 1966-10-12 1969-07-01 Ishikawajima Harima Heavy Ind Roasting process of fine ore and a device therefor
US3539164A (en) * 1967-04-22 1970-11-10 Kloeckner Humboldt Deutz Ag Cooler for hot lump goods,particularly cement clinker
US3612499A (en) * 1969-02-12 1971-10-12 Polysius Ag Apparatus for heat treatment of fine material
US3723597A (en) * 1970-01-23 1973-03-27 Fives Lille Cail Calcining phosphate minerals
US3782888A (en) * 1972-10-04 1974-01-01 Allis Chalmers Method and apparatus for heat treating with heat recuperation from material cooling and auxiliary heat during startup

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3975148A (en) * 1974-02-19 1976-08-17 Onoda Cement Company, Ltd. Apparatus for calcining cement
US4028049A (en) * 1974-03-29 1977-06-07 Ciments Lafarge S.A. Method and installation of treating raw material for producing cement
US4201541A (en) * 1974-06-03 1980-05-06 Fritz Schoppe Process and installation for the production of calcined material
US4110915A (en) * 1975-12-12 1978-09-05 Fives-Cail Babcock Manufacture of cement
US4169701A (en) * 1976-11-29 1979-10-02 Mitsubishi Jukogyo Kabushiki Kaisha Fluidized-bed kiln with preheating means
US4326845A (en) * 1981-01-02 1982-04-27 Allis-Chalmers Corporation Suspension preheater for cement calcining plant
US4511333A (en) * 1981-12-21 1985-04-16 Klockner-Humboldt-Deutz Ag Device for burning cement
US4492570A (en) * 1982-09-02 1985-01-08 Kawasaki Jukogyo Kabushiki Kaisha Calcining system provided with a planetary cooler
DE3517884A1 (de) * 1985-05-17 1986-11-20 Krupp Polysius Ag, 4720 Beckum Anlage zur waermebehandlung von feinkoernigem gut
DE3520927A1 (de) * 1985-06-11 1986-12-11 Krupp Polysius Ag, 4720 Beckum Vorrichtung zur waermebehandlung von feinkoernigem gut
US5562443A (en) * 1992-11-12 1996-10-08 F. L. Smidth & Co. A/S Rotatable cooler for a rotary kiln plant
DE19504589A1 (de) * 1995-02-11 1996-08-14 Kloeckner Humboldt Deutz Ag Rostkühler
US20040029064A1 (en) * 2000-08-24 2004-02-12 Skaarup Jensen Lars Jensen Method and plant for manufacturing cement clinker
US6733283B2 (en) * 2000-08-24 2004-05-11 F. L. Smidth A/S Method and plant for manufacturing cement clinker

Also Published As

Publication number Publication date
JPS4980130A (it) 1974-08-02
DK135869C (it) 1977-12-12
ES421163A1 (es) 1976-04-16
FR2209732A1 (it) 1974-07-05
AU6315973A (en) 1975-06-05
DK135869B (da) 1977-07-04
DE2360580A1 (de) 1974-06-20
DE2360580B2 (de) 1977-10-06
JPS5249494B2 (it) 1977-12-17
CA1003212A (en) 1977-01-11
GB1413055A (en) 1975-11-05
BR7309562D0 (pt) 1974-09-05
FR2209732B1 (it) 1978-04-28
CS212739B2 (en) 1982-03-26
CH578161A5 (it) 1976-07-30
SE406009B (sv) 1979-01-15
IT1005212B (it) 1976-08-20

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