US3643933A - Cooler for rotary kiln - Google Patents

Cooler for rotary kiln Download PDF

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Publication number
US3643933A
US3643933A US87246A US3643933DA US3643933A US 3643933 A US3643933 A US 3643933A US 87246 A US87246 A US 87246A US 3643933D A US3643933D A US 3643933DA US 3643933 A US3643933 A US 3643933A
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United States
Prior art keywords
duct
kiln
tube
end portion
oblique passage
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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
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US87246A
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English (en)
Inventor
Daniel Mcdonald
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.)
Allis Chalmers Corp
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Allis Chalmers Corp
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Publication date
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Assigned to WOODS KATHLEEN D., AS TRUSTEE, CONNECTICUT NATIONAL BANK THE, A NATIONAL BANKING ASSOCIATION AS TRUSTEE reassignment WOODS KATHLEEN D., AS TRUSTEE SECURITY INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: ALLIS-CHALMERS CORPORATION A DE CORP.
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Expired - Lifetime legal-status Critical Current

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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
    • F27B7/38—Arrangements of cooling devices
    • F27B7/40—Planetary coolers

Definitions

  • ABSTRACT A plurality of material cooling tubes are attached in parallel alignment around the periphery of the material discharge end of a rotary kiln.
  • An oblique passage is provided from each tube to the interior of the kiln for conducting air from the tube to the kiln.
  • a first duct is provided for receiving hot material from the kiln. The first duct is within the oblique passage and extends from the kiln a predetermined distance to a terminal portion thereof intermediate the kiln and tube.
  • a second duct is provided which has a first end portion connected to the terminal portion of the first duct and the second duct projects out of the oblique passage to be exposed to surrounding atmosphere.
  • the second duct has a second end portion connected to the tube.
  • the second duct is a spiral that turns away from the adjacent end of at least about 180 to where it discharges material into the tube and the tube projects through the space inwardly of the spiral duct toward the adjacent discharge end of the kiln.
  • the spiral duct being exposed to atmosphere, is cooled and material therein is cooled, to reduce thermal stress in the assembly.
  • the material When material reaches the opposite end of a tube, from the charge end, the material is discharged into collecting or transporting devices as desired. As material moves through the tubes it is exposed to cooling air that is passed through the tubes in the direction opposite to material flow through the tubes. The counterflow of the air through material in the tubes cools the material and heats the air. The heated air passes into the kiln and provides preheated secondary air which combines with fuel and primary air from a nozzle to provide rapid combustion of fuel in the kiln.
  • a problem associated with assembly disclosed in the Krottnaurer patent was that the capacity of the cooling tubes was reduced by the fact that some of the material discharged from the kiln into each tube, as each tube passed through the lowest segment of its path of travel, fell back into the kiln as the tubes approached and passed through the highest segment of its path around the central axis of the kiln.
  • this problem was substantially overcome by providing an oblique passage from the kiln to cooler tubes rather than the radial path shown in the Krottnaurer patent.
  • dusty or fine particle material the oblique passage was not as effective.
  • the material flowing out of the kiln into the cooling tubes and the preheated air flowing out of the cooling tubes into the kiln are kept out of contact with each other. It had been determined that most of the dust pickup by the preheated air occurs near the air discharge end of the cooling tubes and in the passages connecting the tubes with the kiln.
  • the material in the Roubal apparatus is kept out of contact with the air in this portion of the system by providing an enclosed duct within each passage connecting a cooling tube to the kiln.
  • the duct for the material is of smaller crosssectional area than the remaining portion of the passage devoted to air passage.
  • the entry to the duct is located at the upstream edge of a passage opening in the kiln so substantially all of the material drops into the duct and little or none of the material spills over into the air conveying portion of the passage where it can be picked up by the air and carried back into the kiln.
  • Each enclosed duct extends from the port of the passage connecting the kiln to a tube, through the passage into the tube where the enclosed duct makes at least about 1% spiral turns around the inner surface of the tube before dumping material within the tube where the usual spiral flights will take over and move the material through the remaining length of the cooling tube. In some installations of that construction, however, high-thermal stresses have been experienced that resulted in severe cracking of welds that secure the spiral flights within the cooling tubes and the spiral flights themselves have burned away.
  • a plurality of material cooling tubes are attached in parallel alignment around the periphery of the material discharge end of a rotary kiln.
  • An oblique passage is provided from each tube to the interior of the kiln for conducting air from the tube to the kiln.
  • a first duct is provided for receiving hot material from the kiln. The first duct is within the oblique passage and extends from the kiln a predetermined distance to a terminal portion thereof intermediate the kiln and tube.
  • a second duct is provided which has a first end portion connected to the terminal portion of the first duct and the second duct projects out of the oblique passage to be exposed to surrounding atmosphere.
  • the second duct has a second end portion connected to the tube.
  • the second duct is a spiral that turns away from the adjacent end of at least about to where it discharges material into the tube and the tube projects through the space inwardly of the spiral duct toward the adjacent discharge end of the kiln.
  • the spiral duct being exposed to atmosphere, is cooled and material therein is cooled, to reduce thermal stress in the assembly.
  • FIG. 1 is a partial end view of a kiln assembly according to the present invention, with various portions broken away;
  • FIG. 2 is a view taken along line 11-11 of FIG. 1 taken in the direction indicated by the arrows;
  • FIG. 3 is a view taken along line III-III of FIG. 2 taken in the direction indicated by arrows.
  • a rotary kiln assembly 10 comprises a cylindrical shell 1 l lined with refractory brick I2.
  • the kiln assembly 10 is supported and driven by means (not shown) to turn as indicated by the arrow in FIG. 1.
  • a plurality of port castings 13 project obliquely through shell 11 and lining 12 and open to the interior of the kiln I0.
  • a plurality of material cooling and air preheating tubes 20 are arranged around the discharge end of the kiln 10 with a central axis through each of the tubes 20 being parallel with a central axis through kiln 10.
  • Structural means 21 are provided defining an oblique passage 22 from each tube 20 to the interior of kiln I0.
  • Wall structure 23 defines a first duct 24 for receiving hot material from the kiln l0 and conducting the hot material away from the kiln 10.
  • the wall structure 23 defines the first duct 24 within the oblique passage 22 and the first duct 24 extends from the kiln 10 a predetermined distance to define a terminal portion shown as flange 25 intermediate the kiln 10 and tube 20.
  • Wall structure 26 is provided which defines a second duct 27 having a first end portion defined by a flange 28 which is connected to the flange 25, for receiving hot material from the first duct 24.
  • the wall structure 26, which defines the second duct 27, projects out of and away from the structural means 21 which defines the oblique passage 22.
  • the second duct 27 is provided with a second end portion 29 connected to the tube 20 for discharging the material from the kiln l0 and first duct 24 into the tube 20.
  • the second duct 27 is a spiral that turns away from the discharge end of kiln 10. As shown in FIG. 3 the second duct 27, from flange 28 to end portion 29, turns about an axis 30 central of tube 20 at least about 180 to place end portion 29 on a side of tube 20 opposite flange 28.
  • spiral duct 27 projects through the space inwardly of the spiral duct 27 and toward the adjacent discharge end of kiln 10.
  • the spiral duct 27, from flange 28 to end portion 29, is exposed to surrounding atmospheric air and both the duct 27 and the material therein is cooled to reduce thermal stress caused by the material after it enters ducts 20 and makes contact with spiral flights 31 secured within tubes 20 by welds 32 (shown in FIG. 2).
  • hot material will advance through kiln toward the discharge end of the kiln and the port castings 13 as the kiln is rotated about its central axis in the direction indicated by an arrow in FIG. 1.
  • the hot material will spill over the upstream edge of castings l3 and drop into duct 24.
  • Material entering duct 24 will pass through the portion of duct 24 in casting 13, then through the portion of duct 24 in the oblique passage 22 and then through the spiral duct 27 external of passage 22.
  • the rotational motion of the entire assembly will move material through the spiral duct 27, out the end portion 29 and into tube 20. Thereafter material will be moved through tubes 20 by the flights 31 to the discharge ends of tubes 20 (not shown).
  • Cooling air may be admitted into tubes 20 through the material discharge ends of the tubes by any conventional arrangement (not shown) which may be such as disclosed in the earlier mentioned Krottnaurer patent.
  • the spiral duct 27, is exposed to atmosphere and cooled thereby, and does not therefore burn out, nor are welds damaged by overheating such as the welds 32 (FIG. 1) or welds (not shown) that may be utilized to fabricate sheet metal to make the ducts 27.
  • a rotary kiln assembly having a plurality of cooling tubes attached in parallel alignment around the periphery of the material discharge end of the kiln and having means defining an oblique passage from each tube to the interior of the kiln for conducting air from the tube to the kiln, the improvement comprising:
  • a. wall structure defining a first duct for receiving hot material from the kiln and conducting the hot material away from the kiln, the wall structure defining first duct being within the oblique passage means and extending from the kiln a predetermined distance to define a terminal portion of the first duct intermediate the kiln and the tube;
  • wall structure defining a second duct having a first end portion connected to the terminal portion of the first duct for receiving hot material therefrom, the wall structure of defining the second duct projecting out of the oblique passage means from the terminal portion of the first duct and extending therefrom external of the oblique passage means and exposed to surrounding atmosphere, the second duct having a second end portion connected to the tube for discharging the material from the kiln and first duct into the tube with the second duct and the material therein being cooled by its exposure to surrounding atmosphere.
  • the second duct being of spiral configuration with the second end portion thereof discharging material into the tube at a location in a plane perpendicular to the kiln spaced a greater distance from the adjacent discharge end of the kiln than the first end portion of the second duct.
  • the tube having an end portion of reduced diameter projecting through a space defined inwardly of the spiral configuration of the second duct in an axial direction toward the adjacent discharge end of the kiln.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Furnace Details (AREA)
  • Muffle Furnaces And Rotary Kilns (AREA)
US87246A 1970-11-05 1970-11-05 Cooler for rotary kiln Expired - Lifetime US3643933A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US8724670A 1970-11-05 1970-11-05

Publications (1)

Publication Number Publication Date
US3643933A true US3643933A (en) 1972-02-22

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Family Applications (1)

Application Number Title Priority Date Filing Date
US87246A Expired - Lifetime US3643933A (en) 1970-11-05 1970-11-05 Cooler for rotary kiln

Country Status (4)

Country Link
US (1) US3643933A (xx)
JP (1) JPS5134979B1 (xx)
CA (1) CA952712A (xx)
ZA (1) ZA717180B (xx)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3809528A (en) * 1973-09-04 1974-05-07 Fuller Co Apparatus for cooling solid particulate material
US3813211A (en) * 1971-09-20 1974-05-28 Smith S & Co Cooler tubes for rotary kiln
US4021195A (en) * 1975-03-18 1977-05-03 F. L. Smidth & Co. Planetary cooler system for rotary drums such as kilns

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US828555A (en) * 1904-12-23 1906-08-14 Paul O Krottnaurer Rotary kiln.
US3279775A (en) * 1964-11-25 1966-10-18 Allis Chalmers Mfg Co Cooler for rotary kiln
US3372915A (en) * 1965-09-28 1968-03-12 Smidth & Co As F L Rotary kiln assemblies

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US828555A (en) * 1904-12-23 1906-08-14 Paul O Krottnaurer Rotary kiln.
US3279775A (en) * 1964-11-25 1966-10-18 Allis Chalmers Mfg Co Cooler for rotary kiln
US3372915A (en) * 1965-09-28 1968-03-12 Smidth & Co As F L Rotary kiln assemblies

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3813211A (en) * 1971-09-20 1974-05-28 Smith S & Co Cooler tubes for rotary kiln
US3809528A (en) * 1973-09-04 1974-05-07 Fuller Co Apparatus for cooling solid particulate material
US4021195A (en) * 1975-03-18 1977-05-03 F. L. Smidth & Co. Planetary cooler system for rotary drums such as kilns

Also Published As

Publication number Publication date
ZA717180B (en) 1973-06-27
CA952712A (en) 1974-08-13
JPS5134979B1 (xx) 1976-09-29

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Legal Events

Date Code Title Description
AS Assignment

Owner name: CONNECTICUT NATIONAL BANK THE, A NATIONAL BANKING

Free format text: SECURITY INTEREST;ASSIGNOR:ALLIS-CHALMERS CORPORATION A DE CORP.;REEL/FRAME:004149/0001

Effective date: 19830329

Owner name: WOODS KATHLEEN D., AS TRUSTEE

Free format text: SECURITY INTEREST;ASSIGNOR:ALLIS-CHALMERS CORPORATION A DE CORP.;REEL/FRAME:004149/0001

Effective date: 19830329