rotary kiln heat exchangers having precast hub and leg assemblies are disclosed. The hub and leg assemblies include interlocking features which secure the heat exchanger components together. A method of installing such heat exchangers in rotary kilns is also disclosed. Installation is relatively fast and simple, and the heat exchangers are capable of withstanding the harsh operating conditions of rotary kilns for extended periods of time.

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Patent
   RE44612
Priority
Jun 06 2002
Filed
Apr 25 2005
Issued
Nov 26 2013
Expiry
Jun 06 2022
Inventors
Stephansky…
Assg.orig
Harbison-W…
Assg.curr
Harbison-W…
Entity
unknown
Referenced by
0
References
25
Maint.:
EXPIRED
EXAMPLE
2. A rotary kiln comprising:
a refractory lining in the kiln; and
a heat exchanger assembly in the kiln including a heat exchanger hub comprising recesses, and heat exchanger legs each having an inner end received in the heat exchanger hub recesses and an outer end, wherein the outer end of said legs are is installed adjacent to the refractory lining with at least two courses of raised bricks, said raised bricks positioned against each circumferential side of each of said legs between said leg and said refractory lining and the courses of raised bricks have different heights.
1. A rotary kiln comprising:
a refractory lining in the kiln; and
a heat exchanger assembly in the kiln including a heat exchanger hub comprising recesses, and heat exchanges exchanger legs each having an inner end received in the heat exchanger hub recesses and an outer end wherein the outer end of said legs are is installed adjacent to the refractory lining with at least one course of raised bricks, said raised bricks positioned against each circumferential side of each of said legs between said legs and said refractory lining, said raised bricks having a height greater than said refractory lining.
3. A method of installing a heat exchanger in a rotary kiln comprising:
positioning first and second heat exchanger legs in the kiln at initial positions;
installing a hub between the first and second legs by moving the first and second legs from their initial positions to installed positions in which the first and second legs are engaged with the hub wherein at least one of said first and second heat exchanger legs includes recesses and projections dimensioned to engage and interlock with projections and recesses on said hub; and
installing a third heat exchanger leg by engaging sliding the third heat exchanger leg relative to said hub into engagement with the hub; and
pinning said third heat exchanger leg to said hub.
10. A trefoil structure for a rotary kiln, said kiln having a cylindrical body having a metal shell and a refractory brick lining therewithin, said trefoil structure, comprising:
a central hub comprised of a plurality of side-by-side, pre-formed refractory hub sections, said hub sections aligned along a central axis that extends through said cylindrical body; and
a plurality of legs extending radially outward from said hub to said metal shell, each of said legs comprised of side-by-side pre-formed leg sections, each of said leg sections being a unitary cast refractory shape that extends between said central hub and supports on said metal shell, each hub section engaging the inner ends of at least two side-by-side leg sections.
18. A trefoil structure for a rotary kiln, said kiln having a cylindrical body having a metal shell and a refractory brick lining therewithin, said trefoil structure, comprising:
a refractory hub oriented along an axis that extends axially through said cylindrical body, said hub comprised of a plurality of side-by-side pre-formed refractory hub sections; and
a plurality of elongated leg sections that extend radially from said hub to said metal shell, each of said leg sections being an elongated cast refractory shape dimensioned to have an innermost end that engages and interlocks with said hub and an outermost end supported by said metal shell of said cylindrical body, wherein each hub section engages the inner ends of at least two side-by-side leg sections.
4. The method of claim 3, wherein the first and second heat exchanger legs are positioned at four o'clock and eight o'clock positions, respectively.
5. The method of claim 3, wherein the third heat exchanger leg is installed at a twelve o'clock position.
6. The method of claim 3, wherein at least one of said first and second heat exchanger legs includes recesses and projections dimensioned to engage and interlock with projections and recesses an on said hub.
0. 7. The method of claim 6, wherein a third heat exchanger leg slides into position relative to said hub.
8. The method of claim 6 further comprising the step of inserting shims between said kiln and the outer end of at least one of said heat exchanger legs.
0. 9. The method of claim 3, wherein at least one of said heat exchanger legs includes recesses and projections dimensioned to engage and interlock with projections and recesses on said hub, and at least one of said heat exchanger legs is pinned to said hub.
0. 11. A trefoil structure of claim 10, wherein said hub sections are axially thicker than said leg sections, wherein each hub section engages at least two side-by-side leg sections.
12. A trefoil structure of claim 11 10, wherein shims are disposed between said metal shell and at least one of said legs.
13. A trefoil structure of claim 10, wherein the leg sections that form at least one of said legs are axially slidable into engagement with said hub sections forming said hub.
14. A trefoil structure of claim 13, wherein said leg sections are pinned to said hub sections.
15. A trefoil structure of claim 10, wherein at least one of said legs is comprised of leg sections that have innermost ends that interlockingly engage with said hub sections, and at least one of said legs is comprised of leg sections that have innermost ends that slide axially along the central axis of said cylindrical body into engagement with said hub sections.
16. A trefoil structure of claim 15, wherein said leg sections that slide into engagement with said hub sections are locked in position by pins extending into aligned slots in said slidably-aligned leg sections and said hub sections.
17. A trefoil structure of claim 15, wherein said leg sections that interlock with said hub sections have a plurality of recesses and protrusions formed along said innermost end of said leg sections that mate with opposing protrusions and recesses on said hub sections.
19. A trefoil structure of claim 18, wherein groups of said leg sections are arranged side-by-side to form a plurality of equally spaced trefoil legs that extend from said hub to said metal shell.
20. A trefoil structure of claim 19, wherein each of said leg sections includes a protrusion on one lateral side and a recess on another lateral side, said protrusion and said recess being dimensioned, wherein a protrusion on one leg section is matingly received in a recess in another leg section when multiple leg sections are arranged side-by-side to form a trefoil leg.
0. 21. A trefoil structure of claim 20, wherein said hub is comprised of a plurality of side-by-side pre-formed refractory hub sections.
0. 22. A trefoil structure of claim 21, wherein a hub section is thicker than a leg section, wherein each hub section engages at least two side-by-side leg sections.
23. A trefoil structure of claim 18, wherein said leg sections are supported by said metal shell by elongated bars attached to said metal shell, said bars being received in channels formed in the outermost ends of said leg sections.
24. A trefoil structure of claim 23, wherein said channels are formed in the edge of said leg sections.
25. A trefoil structure of claim 18, wherein shims are disposed between said metal shell and the outermost end of at least one of said leg sections.
FIG. 17A is a view of a heat exchanger leg showing shims beneath the outer end thereof. 92 between the outer ends of legs 50, 50a and 64 and kiln shell 32, may be required for one or many of such legs 50, 50a and 64.

In one method of forming legs 50, 50a and 64, such legs are dimensioned shorter than necessary to fit within a given kiln shell, and the legs are then shimmed where necessary to account for areas of kiln shell 32 that are out of round.

As shown in FIG. 17, after installation of the first, second and third legs 50, 50a and 64, and the hub 40, the refractory brick lining 34 is installed against the shell 32, as well as the raised brick courses 74 and 76.

The following example is intended to illustrate various aspects of the present invention, but is not intended to limit the scope of the invention.

EXAMPLE

A heat exchanger is installed in a rotary kiln as follows. After the internal surface of the kiln shell has been exposed and cleaned, the following sequence is carried out.

    • 1. enter kiln and establish a longitudinal centerline on the lowest segment of radius, or 6 o'clock position;
    • 2. measure interior circumference and divide circumference first by one-half and record, then divide the circumference by thirds and record;
    • 3. from the first centerline on floor, measure one-half of the circumference and establish upper point at the 12 o'clock position. From this line measure back down shell both to the left and right one-third of the circumference and establish these centerlines, at approximately the 4 o'clock and 8 o'clock positions;
    • 4. at the 6 o'clock position, set track segments for the rolling support table, the full length of work area;
    • 5. set both monorail segments, approximately 20 degrees to the left and 20 degrees to the right of the upper or 12 o'clock position centerline;
    • 6. establish the starting point of the heat exchanger and mark kiln shell;
    • 7. from each of the three centerlines, at 12 o'clock, 4 o'clock and 8 o'clock positions, set the support channels and weld to shell;
    • 8. set one leg on the left side of a support table, and second leg on the right side of the table, then raise table to up position;
    • 9. set a hub in place on the support table and lower these three items into place;
    • 10. with support table in the down position, set the remaining leg into place and install locking pins; and
    • 11. lower table, roll forward to next position and repeat steps #8, #9 and #10.

This sequence is continued until the heat exchanger is completely installed. Then the support table track and monorail segments are removed and the remaining kiln brick lining is installed.

Whereas particular embodiments of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims.

INVENTORS:

Stephansky, John J., Snyder, John N., Thibault, John

THIS PATENT IS REFERENCED BY THESE PATENTS:
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ASSIGNMENT RECORDS    Assignment records on the USPTO
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Executed onAssignorAssigneeConveyanceFrameReelDoc
Apr 25 2005Harbison-Walker Refractories Company(assignment on the face of the patent)
MAINTENANCE FEES AND DATES:    Maintenance records on the USPTO
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