US3016236A - Rotary kiln discharge end construction - Google Patents

Description

Jan. 9, 1962 B. ALONSO 3,0l6,236

ROTARY KILN DISCHARGE END CONSTRUCTION Filed June 22, 1960 2 Sheets-Sheet 2 mbm 93034401 &do mano/0 Patented Jan. 9, 1962 Bernardo Alonso, Whitefish Bay, Wis., assignor to Allis- Chalmers Manufacturing Company, Milwaukee, Wis. Filed June 22, 1960, Ser. No. 38,021 6 Claims. (Ci. 263-132) This invention relates generally to kilns and the like and more particularly to an end section Construction for the discharge end of a kiln.

A discharge end section for rotary kilns commonly employs a metal ring, usually formed by segments, which act to retain the lining of refractory brick or other material within the kiln and resists any tendency of the kiln lining to fall out of the discharge end. According to early practices in this art, the lining retaining ring was exposed to a very substantial degree, to the high temperature material leaving the kiln. This resulted in the end ring being rapidly burned away by the high temperature material discharged from the kiln. Even before the ring is damaged the ring becomes highly heated and warps, allowing the refractory lining to become loose and fall from the kiln. One attempt of the prior art to reduce the seriousness of this problem is illustrated in the patent to C. S. Lincoln et al., U.S. 2,266,396, granted December 16, 1941. This patent discloses a construction in which the annular lip of lining at the discharge end of the kiln shields the retaining ring to substantially prevent its exposure to the high temperature material being discharged from the kiln. However, after continued use the annular lip of refractory lining eventually wears away and exposes the retaining ring directly to the high temperature material. At such .times only a portion of the annular lip of the refractory material may have been worn away. However, with the arrangement shown in the patent to C. S. Lincoln et al. several feet of good serviceable refractory lining must also be removed because the retaining ring and an end cooling assembly incorporated in that construction are attached to the kiln shell by bolts or rivets passing through the shell, This is the result of the fact that lining must be removed in order to expose these rivets or bolts in order to remove them, remove the worn retaining ring, replace the retaining ring and reinsert bolts or rivets to hold the assembly together.

It is an object of the present invention to provide an improved end section construction for the discharge end of kilns in which the retaining ring is secured to the exterior of the kiln shell by an arrangement that is completely external to the kiln shell to eliminate the need for always removing good serviceable refractory lining when replacing the ring.

Another object of this invention is to provide a new and improved end section construction for the discharge end of kilns that substantially eliminates shearing stresses being imparted to bolts used to secure the retaining ring to the kiln shell. i i

Still another object of this invention is to provide a new and improved end section construction for the discharge end of kilns in that the refractory retaning metal end ring segments are secured to the kiln shell by means that are disposed concentrically about the external surface of the metal shell of the kiln in a manner that subjects the securing means and the portion of the retaining ring to which they are attached to the action of a cooling fluid. v v

A further object of this invention is to provide a new and improved end section constructionrfor the discharge end of kilns which is durable and relatively inexpensive and which can bereadily installed and replaced when\ pletely enclosed from the renote end of the first sleeve necessary with a minimum of'eflort.

According to a preferred embodiment of the present invention, a first cylindrical sleeve is radially spaced around the external surface of the kiln shell. circumferentally spaced ribs engage the outer surface of the kiln shell-and the inner surface of the sleeve and define therewith air passages for cooling the discharge end of the kiln. The annular sleeve is located axially a short distance from the discharge end of the kiln. A first series of lugs circumferentially spaced, and secured to the outer kiln surface as by welding, are arranged adjacent the end of the annular sleeve closest to the discharge end of the kiln. These lugs project radially outward but do not project radially beyond the outer surface of the annular sleeve for a reason that will appear as this description proceeds. The refractory retaining ring, made in segments, provides an annular refractory retaining fiange in approximate abutting relationship to the discharge end of the kiln shell and is provided with an integral annular collar projecting axially from the flange toward the lugs. The annular collar abuts the external surface of the kiln shell. A second series of lugs are formecl integral with the ring or otherwise attached thereto. The second series of lugs project radially outward a distance greater than the first series of lugs, and preferably, so their outer peripheral surfaces are substantially parallel to the outer peripheral surface of the annular sleeve that defines the cooling passages. Each of the lugs of the second series are provided with Slots of sufficent width to receive the' shank portion of a bolt. A bolt is arranged in each slot parallel to the central` axis of the kiln. The bolt is arranged with the head portion on the side of the lug toward the refractory retaining flange. The shank of each of the bolts projects through the slot in the lug of the second series and through an aligned hole in a lug of the first series. A nut is provided on the end of the bolt which when turned tight connects the second series of lugs to the first series of lugs and draws the refractory retaining flange into an abutting relationship with the discharge end of the kiln shell. Thus an extremely simple, inexpensive arrangement is provided to attach the refracto'y` retaining ring to the kiln shell that is entirely external of the kiln shell. Furthermore, the only stresses that will be applied to the bolts that hold this assembly together will be tensile stresses and no shear stresses will be ap thereto, and project axially therefrom in the direction' toward the air passage defining sleeve and may be dis-' posed between lugs of the first series in the same radial` plane. Further, the lugs of the third series project radially outward of the kiln shell but not beyond the air passage defining sleeve. The lugs of the third series are each provided With a slot of sufiicient width to receive the shank portion of a bolt. A bolt is placed in each such slot with the head portion abutting a surface cut in the lug that faces the kiln shell. This bolt projects radially outward beyond the peripheral surfaces of the sleeve, second series of lugs, and preferablyv the refractory retaning fiange. A second annular sleeve formed by a plurality of segments is provided to enclose the annular space between the first sleeve and the refractory retaining flange. These segments abut the outer peripheral surface of the first sleeve, and the outer peripheral surface of the second series of lugs. The bolts `fitted into the Slots in the third series of lugs project through aligned holes in the sleeve segments. Nuts are provided which When turned on the ends of these bolts secure the segments to the refractory retaining flange which is in turn secured to the kiln shell. Thus an air passage is comto the refractory retaining lange. The entire arrangement for securing the refractory retaining ring assembly to the kiln shell is thereby contained within an enclosed space that may be cooled by the injection of air in a manner that is conventional.

Other features and objects of the invention that have been attained will appear from the following more detailed description of the invention with reference to the accompanying drawings, in which:

FIG. 1 is a sectional View of a kiln end section construction enbodying the invention;

FIG. 2 is a fragment of the top View of the Construction shown in FIG. 1; and

FIG. 3 is a View of a single segment of a kiln lining retaining end ring assembly according to the present invention, with certain portions of the segment broken away to more clearly show the configuration of the segment.

Referring to FIG. l, a portion of a rotary cylindrical kiln on the discharge end thereof is shown comprising a kiln 'shell 1 having a lining 2. of refractory material arranged around the internal surface of the shell 1. An outer shell is provided around the discharge end of the kiln 1 comprising an adjoining cylindrical portion 4 and a cone frustum forming portion 5. The cone frustum portion 5 is attached, as by welding, to the end of the cylindrical portion 4 that is remote from the discharge end of shell 1. The cylindrical section 4 may be connected in spaced arrangcment to the outer periphery of the shell 1 by a number of circumferentially spaced ribs 6. A nozzle 7 may be provided to blow air into the space between the outer shell 4, 5 and inner shell 1 along a path indicated by the arrows in FlG. 1 to cool the discharge end of the kiln. The passage between the outer shell 4, 5 and kiln shell 1 is enclosed about the discharge end of the ki'n shell 1 by a plurality of sleeve segments 8 and a plurality of ring segments` 9 that are mounted in a manner unique to the present invention that will be described in detail. In addition to enclosing the space between outer shell 4, 5 and kiln shell 1 to completely enclose the cooling air passage, the ring segments 9 also act to abut against the refractorylining 2 within the shell 1 to retain the lining within the shell.

In order to secure the ring segments 9 to kiln shell 1, in a manner to be described later, a first series of lugs 12 are peripherally spaced around an external surface of the shell 1 and connected thereto, as for example, by weldng. Each of these lugs 12 is provided with an axially extending bore 13 as indicated in the lug 12 shown in section in FIG. 2.

Referring to FIG. 3, a ring segment 9 is shown having a first cylnder forming portion 16 and a second cylinder forming portion 17. A flange portion 18 projects radially inward of the portion 16 and joins both cylindrical forming portions 16 and 17. A flange portion 19 is made integral with the 'portions 16, 17 and 18 and portion 19 projects radially outward of the cylinder forming portion 16. Segment 9 is provided with one or more lugs 21 that, when all segments 9 are assembled around shell ll in a manner that Will' be described, provide a second series of circumferentially spaced lugs. As shown in FIG. 3, the lugs 21 of the second series project radially outward from the cylnder forming portion 16 and axially away from portion 19. Each of said lugs 21 is provided with an axially extending slot 23 opening in an axial direction away from the portion 19 and the slot also opens through the periphery of the lug. A bolt head receiving recess 24 is disposed in alignment with the slot 23 that also opens through the periphery of the lug. As shown in FIG. 2 and FIG. 3, shoulders 25 project axially from flange portion 19 at the outer radius of lugs 21 to provide peripheral surfaces that merge with the peripheral surfaces 22 of a pair of adjacent lugs 21. The shoulder's' 25 provide peripheral extensions of the surfaces 22 for a purpose that will appear when the assembly of segments 8 and 9 is described.

ject radially outward from portion 16. The third series of lugs 26 which project toward and through the radial plane defined by the first series of lugs 12 are also circumferentially arranged with each lug 26 projecting aX- ially between an adjacent pair of lugs 12 as is also shown most clearly in F-IG. 2. As shown in FIG. 2 and FIG. 3, each of the lugs :26 is provided with a slot 30 extending radially outward therethrough and a bolt head receiving recess 31 disposed and in radial alignment on the radially inner end of the slot For the purpose of describing the assembly of segments 8 and 9 atter'tion is directed to all three' figures of the drawing, but with regard to FIG. 1 in particular attention is directed to the reference numerals appearing on the lower half of FIG. l. The segments 9 are assembled about the discharge end of shell 1 to provide an annular ring assembly to retain the refractory material 2 within the shell 1. The sleeve segments 8 are also assembled around the discharge end of shell 1 in a manner that Will also be described. Segmente 8 cooperate with the ring of segments 9 to enclose an end portion of the cooling passages defined between outer shell 4, 5 and kiln shell 1.

To assernble the ring of segments 9, a bolt 35 is arranged with its head portion 36 fitted in the recess 24 of each of the lugs 21 and its shank portion 37 projecting axially through the slot 23. The segment 9 is then mounted on the discharge end of shell 1 with its cylinder forming portion 16 engagng the outer pe ripheral surface of shell 1 and its cylinder forming por tion 17 engagirg the inner peripheral surface of shell 1. As the segment 9 is being fitted to the discharge end of shell 1, the bolts 35 are aimed so their shank portions 37 pass through the holes 13 in each of the lugs 12. As is evident in FIG. 2, it is desirable to use bolts having square heads 36 because with the heads fitted in the slots 24, the side walls of the slots 24 will hold the bolts against turning. Nuts 38 are appled to the ends of each of the bolts 35 projecting through the holes 13 in the lugs 12. Thus each segment 9 is secured to the outer periphery of the kiln shell 1 and the need to replace any or all of the segments 9 will not then require the removal of refractory material 2. Furtherrnore, in tightening the nuts 38 on the bolts 35 the bolts will be subjected to primarily tensile stresses. Likewise, thermal extension of the refractory material 2 pushing outwardly on the segments 9 will apply primarily tensile stresses to the bolts 35. Thus the present arrangement substantially eliminates the possibility of any shear stresses be ing applied to the bolts 38. If bolts holding a retaining ring in place'are sheared off, the refractory material will fall from the kiln shell 1. v

After the second series of lugs 21 have been bolted to the first series of lugs 12 in the manner described, the sleeve segments 8 can be easily and Conveniently bolted to the third series of lugs 26 in a manner that will now be described. To mount the segments 8 to the discharge end assembly of the kiln a bolt 40 is arranged with its head portion 41 in the recess 31 of a lug 26 as is shown most clearly with respect to a lug 26a in FIG. 2 that is shown in section. The shank portion 42 of the bolts 40 projects radially outward through slot 30 of the lugs 26 as is shown most clearly with regard to a lug 26b in FIG. 2. The shank portions 42 of the bolts 40 additionally project radally outward through the holes 39 in the segments 8 as shown in the lower portion of FIG. 1. Each of the segments 8 overlaps a portion of the outer perpheral surface of cyldrical i i i portion 4 and the segments 8 also overlap the peripheral surfaces 22 of the lugs 21 (see upper half of FIG. 1) and the shoulders 25 (see FIGS. 2 and 3). Thus both axially spaced end portions of the segments 8 engage supporting structure and tightening nuts 43 on the ends of the bolts 40 that project through the segments 8, rigidly secures the segments 8 to the assembly. As shown in FIGS. land 2, a small space may be provided between the adjacent portions of the segments 8 and the segments 9 to permit aXial expansion of the segments 8 toward the segments 9 without thereby stressing bolts 35. Thus, When the sleeve segments S have been attached in the described manner to the kiln the cooling passages between outer shell 4, 5 and kiln shell 1 will be substantially closed on the discharge end of the kiln. However, since the shoulders 25 and peripheral surfaces 22 do not provide a continuous scaling surface with the segments 8 around the entire periphery of the kiln, some leakage of cooling air will occur through the space between the segments 8 and 9. This, however, is not necessarily undesirable because the escapng of some of the cooling air at this point Will act to more effectively cool the segments 9 which are in relatively close proximity to hot material being discharged from the kiln.

From the foregoing it can be seen that the present invention provides a discharge end Construction for kilns that Will be dur able, relatively inexpensve and which can be readily assembled and disassembled when necessary. Furthermore, and in addition to providing an arrangement which eliminates the need for any mounting bolts passing through the kiln shell, the present invention also results in the bolts 35, lugs 12, lugs 21, bolts 40 and lugs 26, all being located within the passage through which a cooling fluid can easily be passed in a manner conventional in this art.

Thus it can be seen that the described Construction accomplishes the objects of the invention previously referred to. However, modifications and equivalents such as readily occur to those skilled in the art are intended to be included within the scope of this invention and thus the invention is intended to be limited only by the scope of the claims appended hereto.

Having now particularly described and ascertained the nature of my said invention and the manner in which it is to be performed, I declare that What I claim is:

1. A member adapted to coact and form with similar members a lining retaining end ring presenting a cylindrical portion adapted to engage the outer surface of a cylindrical kiln shell adjacent one end thereof and an annular fiange projecting both radially outward and radially inward of said cylindrical portion, comprising, a

metal ring segment having adjoining cylinder and radially outward and radially inward projecting flange forming portions, and a series of circumferentially spaced lugs projectng radially outward from said cylinder forming portion, each of said lugs having an axially extendirg U-shaped slot open in a radially outward direction and futher said lugs having a bolt head receiving recess also open in a radially outward direction, said recess being disposed in alignment with 'said axial'slot opening on the end of said slot nearest said flange, said lugs thereby each being adapted to hold a bolt with its shank portion projecting through said slots insaid lugs in a direction away from said flange forming portion for connecting said segment to said kiln shell.

2. A member adapted to coact and form with similar I members a lining retaining end ringpresenting a cylini drical portion adapted to project within an annular cooling space defined at least in part by a radially spaced segmented sleeve around the discharge end of a cylindrical kiln shell, said cylindrical portion being additionally adapted to engage the outer surface of said cylindrical kiln shell adjacent the discharge end thereof and an annularflange projecting radially inward of said cylindrical portion and shell and said annular flange also having an axially extending U-shaped slot open in a radially outward direction and saidlugs having a bolt head receiving recess also open in a radially outward direction, said recess being disposed in alignment with said axial slot opening on the end of said slot nearest v said flange, said lugs thereby each being adapted to hold a bolt with its shank portion projecting through said lugs in a direction axially away from said flange forming portion for connecting said segment to said kiln shell, and a series ,of circurnferentially spaced lugs axially spaced from said flange forming portions and projecting radially outward from said cylinder forming portion, each of said lugs spaced axially from said flange formng portions having a radially extending U-shaped slot open in an axial direction toward said flange forming portions and a bolt head receiving recess disposed, in alignment with the end of said radal slot nearest said cylinder, said radial slot and said radial slot aligned bolt head receiving recess being adapted to hold a bolt With its shank portion projecting in a radially outward direction through said radial slot for connection toa segment of said sleeve about said kiln end.

3. A member adaptedto coact and form with similar members a lining retaining endring presenting a cylindrical portion adapted to project within an annular cooling space defined at least in part by a radially spaced segmented sleeve around the discharge end of a cylindrical kiln shell, said cylindrical portion being additionally adapted to engage the outer surface of said cylindrical kiln shell adjacent thedischarge end thereof and an annular flange -projecting radially inward of said cylindrical portion and shell andsaid annular flange also projecting radially outward to engage the end surface of ,V said segmented sleeve, comprising, a metal ring segment' having adjoining cylinder and radially outward and radially inward projecting flange portions, a series of circumferentially spaced lugs projecting axially away from said flange forming 'portions and radially outward from said cylinder forming portion, each of said lugs having an axially extending U-shaped slot open in a radially outward direction and said lugs having a bolt head'receiving recess also open in a radially outward direction, said recess being disposed in alignment with said axial. slot opening on the end of said slot nearest said flange, said lugs thereby each being adapted to hold a bolt with its shank portion projecting through said lugs in a direc' tion axially away from said flange formng portion for connecting said segment to said kiln shell, and a series of'circumferentially spaced lugs axially spaced from said flange forming portions and projecting radially outward from said cylinder forming portion, said lugs axially spaced from said flange portions being circumferentially arranged With each projecting axially on a line between, adjacent axially slotted lugs, each of said lugs axially' spaced from said flange portions having' a radially exof said shell and a lining retaining end ring assembly having a cylindrical portion projecting within an annui &016336 E lar cooling space defined at least in part by a radially spaced segmented sleeve arranged around the discharge end of said shell, said cylindrical portion engaging the outer surface of said cylindrical shell adjacent the discharge end thereof, and an annular flange projecting radially inward of said cylindrical portion and said shell to abut against at least a portion of said lining and said annular fiange also projecting radially outward of said cylnder forming portion, said ring assembly comprising a plurality of metal ring segments each having a portion that is a segment of a cylinder and radially outward and radially inward projecting flange portions, said kiln shell having a first series of lugs Secured in peripherally spaced relation to the external surface of said shell, a second series of circunferentially spaced lugs projecting radially outward from said cylinder for'rning portions of said ring segments, each of said second series lugs having an axially extending U-shaped slot open in a radially outward direction and each of said lugs having a bolt head receiving recess also open in a radially outward direction, said recess being disposed on the end of said slot remote from said first series lugs and in alignment with said axial slot opening, a bolt in each said second series lug held with its shank portion projecting through said second series lugs in a direction' toward engagement with a lug of said first series, and means connecting each of said bolts to a lug of said first series.

5. A rot'ary cylindrical kiln comprising, a kiln shell, a refractorylining arranged around the internal surface of said shell and a lining retaining endi ring assembly having a cylindrical portion projecting within an annular cooling space defined at least in part by a radially spaced segmented sleeve arranged around the discharge end of said shell, said cylindrical portion engaging the outer surface of said cylindrical shell adjacent the discharge end thereof, and an annular flange projecting radially inward of said cylindrical portion and said shell to abut against at least a portion of said lining and said annular flange also projecting radially outward of said cylinder forming portion, said ring assernbly conprising a plurality of metal ring segments each having a portion that is a segment of a cylinder and radially outward and radially inward projecting flange portions, said kiln sheil having a first series of lugs Secured in peripherally spaced relation to the external surface of said shell, a second series of circumferentially spaced lugs projecting radially outward from said cylinder forming portions of said ring segments, each of said second series'lugs having an axially extending U-shaped slot open in a radially outward direction and each of said lugs having its side facing said flange forming portion provided with a bolt head receiving recess also open in a radially outward direction, said recess being 'disposed on the end' of sai-:l axial slot remote from said first series lugs and in alignment with said axial slot opening, a bolt in each said second series lug held with its shank portion projecting through said second series lugs in 'a direction toward engagement with a lug of said first series, means connecting each of said bolts to a lug of said first' series, and a third series of circumferentially spaced lugs projecting radially of 'said cylinder portion and in an axial direction toward said first series lugs, each of said third lugs having a radially outward extending U-shapecl slot r open n an aXal drecton toward said flange fornung portions and a bolt head receiving recess disposed in alignment with the end of said radial slot nearest said cylinder, a bolt in each of said third series lugs held with its shank portion projecting in the radially outward direction through said radial slot in said third series lug, and means connecting each of said bolts in said third series lugs to a segment of said sleeve about said kiln end.

6. A rotary cylirdrical kiln comprisng, a kiln shell, a refractory lining arranged around the internal surface of said shell and a lining retaining end ring assembly having a cylindrical portion projecting within an annular cooling space defined at least in part by a radially spaced segmented sleeve arranged around the discharge end of said shell, said cylindrical portion engaging the outer surface of said cylindrical shell adjacent the discharge end thereof, and an annular flange projecting radially inward of said cylindrical portion and said shell to abut against at least a portion of said lining and said annular ange also projecting radially outward as far as the outer peripheral surface of said segmented sleeve, said ring assembly comprising a plurality of metal ring segments each having a portion that is a segment of a cylinder and radially outward and radially inward projecting fiange portions, said kiln shell having a first series of lugs Secured in peripherally spaced relation to the external surface of said shell, a second series of circumferentially spaced lugs projecting radially outward from said cylinder forming portions of said ring segments and axially away from said flange forming portons, each of said second series lugs having an axially extending U-shaped slot o en in a radially outward direction, and a bolt head receiving recess also open in a radially outward direction, said recess being disposed on the end of said slot rernote from said first series lugs and in alignment with said axial slot opening, a bolt in each said second series lug held with its shank portion projecting through said second series lugs in a direction toward engagement with a lug of said first series, means connecting each of said bolts to a lug of said first series, and a third series of circumferentially spaced lugs being axially spaced from said radially outward flange forming portion and projectingin an axial direction toward said first series lugs and radially outward to the internal surface of said segmented sleeve, said third series lugs being circumferentially arranged with each projecting axially on a line between adjacent second series lugs, each of said third lugs having a U-shaped slot open in an axial direction toward said flange forming portions and with the walls of said slot extending radially outward and a bolt head receiving recess disposed on the radially inner end of said slot and in alignment with said slot, a bolt in each of said third series lugs held with its shank portion projecting in the radially outward direction through said slot in said third series lugs, and means connecting each of said bolts in said third series lugs to a segment of said sleeve about said kiln end. i

References cited in the file of this patent UNITED STATES PATENT S 2,256,396 Lincoln et al. Dec. 16, 1941 2,321,217 Lerner June 8, 1943 FOREIGN PATENTS %0,671 Germany Dec. 28, 1953

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