US1641445A - Pulverizing apparatus - Google Patents

Description

' 1,641,445 P 1927' w. J. A. LONDON PULVERIZING APPARATUS Filed Jan; 28. 1925 e sheets-sheet 1 INVENTOH 7 BY WZ/ZNEYG 6 Sheets- Sheet 2 Filed Jan. 28,1925 1 fang?? I By Sept. 6,1927. ,4 5 7 W.. J. A. LONDON PULVERI Z ING APPARATUS Filed Jan. 28. 1-925 6 Sheets-Sheet 5 NI/E/VTOR WfMa ATTORNEYS Sept. 6, 1927.

w. J. A/LONDON PULYERIZING APPARATUS Filed Jan. 28. 1925 6 Sheets-Sheet 4 I Z7 I Ami/ Er 1 Sept. 6, 1927. 1,641,445 W. J. A. LONDON PULVERI Z ING APPARATUS Filed Jan. 28, 1925 6 Sheets-Sheet 5 L 2 J ATTORNEYS Sept. 6, 1927. 1,641,445

w. J. A. LONDON PULVERIZING APPARATUS Filed Jan, 1925 6 Sheets-Shet 6 a m m 7 m 1N V m M 0 xx 1 .l/ J l 1 0 v fl d f a 6 6 w d 0 z 2 Z 4% Y Z i. 1 Aw\w\\ r V// Patented septa 6, 19 27.

UNITED STATES PATENT OFFICE.

WILLIAM if. A. LONDON, OF HARTFORD, CONNECTICUT, A'SSIGNORTO INTERNATIONAL COMBUSTION ENGINEERING CORPORATION, A CORPORATION OF DELAWARE.

' PULVERIZING APPARATUS.

Application fi1ed .Tanuary 28, 1925. Serial No. 5,193.

This invention relates to pulverizing apparatus and more particularly for pulverizing coal for burning in powdered form.

The object of the presentinvention is to provide a pulverizer which is effective for its intended purpose and which is relatively simple in construction and the interior. parts of which are readily] accessible for renewal and 'repair.. In a pulverizer constructed according to this invention the rotary portions thereof including the impeller canbe removed as a whole in a comparatively short time-and any worn parts thereof readily replaced.

The above and other'advantages can be realized by the construction hereinafter more particularly described andclaimed.

The accompanying drawings illustrate by way of example one embodiment of this invention and in these drawings:

Fig. 1 is a front elevation, partly in section of a double type of pulverizer. n

Fig. 2 is a side elevation of the pulverizer in part section.

Fig. 3 is a front sectional elevation corresponding to Fig. 1 through part of the pul-' verizer. 4

Fig. 4 is a transverse sectional view of the pulverizer taken substantially 0n the line -4-4 of Fig. 1 with the rotary impeller removed.

-Fig. 5 is a partial side view of the mpeller shown in Fig. 1, on a larger scale and in part section.

" this application. Inorder to obviate exces- Fig. 6 1s a cross sectional view taken on the line 6 6 of Fig. 5.

Fig. 7 is a sectional view taken on the line 7-7 of Fig. 2.

The apparatus here illustrated is adapted to form part of a pulverizing system such as-set forth in the U. S. application of John E. Bell, Serial No.- 625,193, filed March 15th,,1923, and assigned to the assignee of sive expenditure of power, air is admitted to the pulverizing apparatus only in limited amounts, preferably not exceeding materially the minimum required for the handling of the pulverized product. When the pulverizer is operated as hereinafter indicated, the air may be limited to from 50 to' 100 per centlof the fuel by'weightr For this purpose, a suflicient depth of coal to act as a partial seal may .be maintained in the supply bin, and the area of the supply conduit or feeder casing may also be appropriately limited.

Referring to the drawings, the apparatus comprises what may be somewhat loosely termed a centrifugal rotary impeller 1 with blades 2 for acting on the coal. ,The impeller is mounted on a shaft 3 that revolves insuitablymounted bearing structures .or

pedestals 4 and is driven by any suitable means not shown. The impeller 1 is enclosed in a casing \or housing divided in halves 5 and 6 for convenience in assembling the machine or opening it up. In the construction illustrated the housing is divided diametrically at 5 so that the portion or cover 6 may be turned on a pivot or" shaft 7 mounted upon the fixed portion of the housing. The adjoining portions of the casing along the line5 are provided with flanges 8 formed with recesses for thereception of bolts 9 whereby the cover 6 is se- The housing is also divided vertically and each divided portion is formed with a flange 5 having holes 5 forthe reception of bolts (not shown) whereby the housing is secured together vertically. It will be seen'therefore that-each of the portions 5 and 6 of the housing are formed of' two parts bolted together through the flanges 5".

The cover 6 is provided on each side thereof with a laterally projecting arm 10 from which is suspended a slotted link 11 connecting the said arm with a cap 12 mounted upon the bearing structures or pedestals 4 which support the impeller shaft 3. The link 11 on the left hand side as, viewed in Fig. 1 is attached to a yoke 13;which connects the cap 12 with a cap 14 mounted upon a support for a thrust bearing 15 so that as hereinafter described, the two caps 12,12 and the cap 14 can all be raised together.

The bearing structures or pedestals 4 are supported upon box-like structures 16 projecting from either side of the casing and formed integral therewith as shown in Fig.

cured to the fixed portion of the housing.

cooling coil 19 is provided for keeping the lubricant cool.

Crushed coal to be pulverized is supplied to the impeller 1 from either sidethrough intakes 19 to which the coal is conveyed from a hopper 20 by screw conveyors 21 driven by a motor 22 through pulleys 23 and belts 24. The discharge outlet 25 of each intake communicates with a chute ordcE- flector 26 which causes the coal to flow into the impeller 1 whence the coal is discharged peripherally into a surrounding annular receiving chamber 27. This chamber has a discharge outlet 28 at its bottom and increases inicross-section, by gradual enlargement both laterally and radially, either way' around from top to bottom. That is to say the impeller axis is substantially above the centers of the casing 5 and the chamber 27. In the path of the discharge from the impeller outward into the chamber are impact surfaces for shattering any doal lumps that may reach them, "afforded by members 29 mounted in the casing 5. In the. construction illustrated the members extend across a relatively narrow annular throat 30 between the impeller periphery and the ans nular chamber. The members 29 are in the form of rectangular plates thin in cross-section compared with their length and breadth and are held in slots 31 formed in liners 32 secured to the Walls of the casiiig 5* on the inner faces thereof. These liners; are provided for the purpose of taking up wear and are readily renewable. They are annular' in form of the cross-section shown in Figs. 1 and 3, with a concave 33 adjacentthe casing 5 and a convex surface 34 on the impeller side. the two liners thus forming the throat 30 through which the coal is discharged. The slots'31 for the reception of the members 29 are formed in this projectingpprtion of the vannular liners and it will be 0 served'that the slots are greater in X length than thewidth of the members, thus facilitating the removal of the latter for renewal. Each member is held in position by a pair of set- screws 34, 35 at each end one of which set-screws (34) has a pointed end 36 which enters a correspondingly shaped recess 37 in the end of the member 29 but this recess has its axis eccentric to the axis of the set-screw, as shown more clearly in Fig. 3, so as to provide an inclined plane against which the end of the set-screw bears. with the result that when the set-screws 34 are advanced the member 29 is seated on and forced against the outer edges of the slots 31. I The member 29 is then further held against longitudinal movement by the other set-screws 35 which are butt-ended to bear against the ends of the member 29. These set- screws 34, 35 are passed through screwthreaded holes 38in the walls of the housing 5 and areprovided ,vith lock-nuts 39 for memes holding themin the positions to which they have been adjusted. 2

' The impeller. 1 comprises a radially tapering disc 40 mounted fast upon the shaft 3 and disposed centrally between two annular discs 41, 41 which are so shaped as to form on either side of the central disc an opening 42. for the admission of coal tothe central intake pace in the interior of the impeller 1, and diverging outlets '43 through Whichthe coal is discharged. The impeller "is provided with blades 2 as best Seen in Figs. 5 and 6 each of which is tapered to correspond with the diverging outlet 43 and is formed on one face with a recess 2 while its longitudinal: edges are formed with flan'ges'2. Thev tapered disc 40'is formed with tapered extensions .44 disposed on opposite sides thereof vand integral therewith. s A blade 2 is mounted on eaph of these'exte sions by engaging the recessed portion 2 thereof with one side of the said extension and then the blade is secured to the extension by a stud 45 which is passed through an in-' clined hole 46in the extension the end of the W stud beingscrew threaded to engage a screwthreaded hole in the blade. The studs 45 merelyserve to support the blades and are not subiected to any stress during the rotation of the impeller. Each extension 44 has also formed in the free outer edge'thereof a slot 47 to receive the head of the stud. The outer'ends of the extensions 44 enter cor; responding recesses 48 in the annular discs 41. and the impeller disc and annular discs nu thus assembled are permanently secured together by rivets 49.

In order to take up wear and to protect the faces of the central disc 40 and the annulafdiscs 44 where same form the outlets from the impeller these'faces are provided with wearing plates 50 of the shape best shownin Fig. 5 which platesare interposed between the extensions 44. Each plate has the edge adjacent to the oneextension con- 1 10 vex from theinner periphery to the extension, then recessed'as at 51 to receive one edge of the extension 44 and has a straight edge 52 whichabuts against the said exten-.

sion. Theopposite edge of the"plate 50 has 5 a portion concave from the inn-er periphery to the extension, a recessed portion 53 to receive the edge of the extension next in order, a curved portion 54 which surrounds the lat-i ter extension and a straight portion 55 which abuts against the wearing plate next in order. In this manner. the seyeral Wearing plates snugly engage the onewith the other and when .it is desired to remove any one of these plates the adjacent blades 2 are first 1-25 removed by Edetaching their studs 45 and withdrawing the blades, the plate 50 is then i moved along the extension until it is over the slot 47 in the latter. This plate will nowbe in aposition with its curved portion 54 over the slot 47. whereupon the plate is turned, which turning is permitted by the curved portion 54 of the plate passing through the slot 47 in one extension 44 while theconvex edge of the plate passes the op posing face of the adjacent extension. The plates are composed of wear resisting material such as manganese steel and the blades are also preferably composed of similar material.

As previously stated the coal to be pulverized is supplied laterally through the intakes 19. .Each of these intakes together wvit-h its conveyor 21 is a separate part divided verticallythrough the hopper 20. The outlet from the intake 19 discharges into the chute or deflector 26 which is of the form the housing 5 and the chute or deflector'26 is inserted therein by raising the cover 6 of the housing, engaging the ridge 26f with the shown in Figs. 1, 3 and 4 and has an inclined surface 26 tending to deflect the coal into the opening 42 of the impeller. The defleeting surface extends from a vertical arcuateflange or support 26 having a curved ridge or rib 26 for engaging a correspondingly shaped groove 26 in the housing. The groove 26 is formed in the fixed portion of groove and moving the deflector along'the groove until it reaches a stop fixed to the housing. When the cover 6 is again closed -a stop 56 thereon holds the chute inposithe portion 58 and the shaft 3. 'The guard is also provided with an arcdate plate 60- adaptedto engage the cover 6 and guide it into place, when the cover is lowered into position. This plate 60 ensures. proper registry of the two portions of the impeller casing.

g The annular discs 41 of the impeller are provided with hollow trunnions 61 which work in bearings supported upon rings 62 mounted in the walls of the housing as best shown in Fig. 3.

- The portion or cover 6 of'the housingis 7 provided on each side wall with a hook 63 pivotally mounted thereon in a plane above. the plane of thesli'aft- 3 andpreferably in alignment with the centre of the shaft; the free end of the hook being supported when not required for useupon a support 64 projecting from the wall of the cover 6. The

front wall of the cover is provided with two flanges 65 and to each of these flanges are attached, below the axis of the shaft 3, the

lower ends of a pair of links 66" the upper ends of which are connected by a shaft 67 with the corresponding pair of links-on the other flange of the cover. Upon the shaft 67 is mounted a yoke 68 whereby) the cover 6 may be, raised by anysuita le means. LWhen' it is desired to remove the impeller 01 thebolts 9 connecting the two portions of the housing and the bolts retaining the bearing caps 12, 12 and 14 are first taken our. The cover 6 is then raised by pulling the yoke'68 upward with the result that during the first part of the upward movementof therover about its pivot 7 the laterally extend:

ing arms 10 thereon will lift the caps 14, 12, 12 of the bearings 15, 4, 4, same being effected by reason ofthe links 11 which connect the arms 10 to, said caps. When the cover 6 has been raised sufliciently the hooks 63 are swung clear of the supports 64 and into engagement with the impeller shaft 3 so that on further movement ofth'e cover the shaft will be raised from its bearings. The impeller and shaft '3 can now be readily removed on a suitable truck and another impeller placed. in position;

The casing; may ,be provided with one or more peripheral manholes 69 or other open-' ings affording convenient access to the chamber 27 and these openings may be closed by covers 70 having their inner surfaces curved in conformity with the interior of the casing.

In the operation of the pulverizer the 1mpeller may be rotated at a uniform peripheral speed as high as about 36000 feet per minute, with the result that a high velocity is imparted to the air entering the apparatus and cohsequently a suction is created suflicient to draw the coal from the intakes to the central openings of the impeller. At

this point the coal lumpstend to spreadannularly and to pass toward the blades,

almosta thousand of whichpass agiven point in a second. The'number and arrangement of the blades 2 is such that the-delivery a d discharge of coal to and from them is ubstantially uniform.- .The coal is reduced by the blades and the producttis discharged from the impeller at a high linear velocity to strike the impact members '29 -with the result that'if there are any pieces not reduced, these are shattered and reduced I to a suitable degree of fineness.

What I claimis: 1. A pulverizer comprising a rotary 1mpeller and a shaft therefor. a casing for said impeller comprising portions separable at said shaft, and an annular guard around said shaftwithin tliecasing, removable with the shaft when the casing is opened.

4 2. A pulverizer comprising a rotary. impeller and a shaft therefor, a casing for said impeller comprising hinged portions divided so as to open at said shaft, an annular guard around said shaft within the r p i H O I casing, and means on said guard for 1118111- said shaft, and a supply chute for said inn-- peller beneath the shaft engaged with a lower casing portion and held in place therein by an upper one when closed, but released for removal when such upper portion is openedw A 4. A centrifugal pulverizer comprising an impeller disc, a shaft on which said disc -is mounted, a casing for said impeller divided into two portions one of which is pivoted to the other, bearings supporting said shaft, covers for said bearings and means connecting the pivoted portion ofthe casin to said covers whereby the covers for said earings are raisedsimultaneously with the raising-of the pivoted portion of the casing.

5. A pulverizer comprising a centrifugal impeller, a casing for the impeller divided into two portions pivoted the one to the other, an annular throat in said casing, a receiving chamber into which sald throat .opens, a serles of impact members in said casing.

mounted in said openings. Q

i 8. A pulverizer impeller comprising a centhroat in the pathof the .discharge therefrom outward into said receiving chamber, and

the

6. A pulverizer impeller comprising discs spaced apart, a disc intermediate the spaced discs and forming therewith outlet passages means for raising the pivoted portion of which diverge outwardly, and detachable blades interposed between the centraldisc and the outer discs.

i 75 Apulverizer impeller comprising a central tapered disc discs on either side thereof and spaced therefrdm'to provideopenings diverging outwardly, and detachable blades tral disc, discs on either side thereof and spaced therefrom to provide'outlet passages, wlateral extenslons on either side of the central disc and abutting against the outer discs,

and blades detachably mounted on said extensions. i 4 v 9. A pulverizer impeller comprising a cen tral disc, discs on either side thereof and spaced therefrom to provide outlet passages,

a series of lateral extensions on either side. of the central disc and withinsaid passages, blades detachably securedto. said extensions,

-and removable face-plates mounted on said dISCS within the said passages.

.10, A pulverizer having an mlieller comprising a central disc, discs on either side thereof and spaced therefrom to provide outlet passages, andblades detachably mounted in said passages in combination with acasing enclosing said impeller, said casmg having an annular restricted portion mg a nearest forming a throat aro,und said impeller and a series of impact members in said throat 11. A pulverizer having an impeller comprising a central disc, discs on either side,

thereof and spaced therefrom toprovide outlet passagesiand blades detachably mounted in said passages, in combination with a having an annular restricted po tion form-u said passages, a casing enclosing said impeller discs. annular; liners in said casing forming a throat around said impeller, and a series of impact members in said throat. 13.111 a pulverizer the combination of a centrifugal impeller disc, discs on either side thereof and spaced therefrom to provide outlet passages, blades detachably mounted,

in said passages, a casing enclosing said impeller dISCS, annular concavo convex liners in said casmg formlng a throat around said impeller, and a series of impact members in said throat. o

- 1% A pulverizer comprising a centrifugal impeller, a shaft on which said impeller is mounted, a casing for the impeller divided into two portions pivoted the one to the other, an outlet from saidcasing an annular throat in said casing, a receiving chamber into which said throat opens and increasing let,\a series of impact members in said throat in thepath outward into said receiving chamber, means, for raising the pivoted portion of the 'casingyan annular guard carried by the casing and embracing the impeller shaft and means on said guard for ensuring proper registry'of the casing parts when said parts arebrought together.

" cross section from its top around to said out- 15. A pulverizer comprising in combinareceiving chamber into which said throat opens and increasing in cross section from its top around to said outlet, a series of impact members in said throat in the pathQoutward into said receiving chamber, means for-raising thevpivoted portion of the cas ing, an annular guard carried by the casing and embracing the impeller shaft, and a dowel on said gifard for ensuring proper tion a centrifugal impeller, a shaft on which I registry of the casing parts when said parts are brought together.

16.- A pulverizer comprising in combination a centrifugal impeller, a,shaft on which said impeller is mounted, a casing for the impeller divided into two portions pivoted the one to the other, an outlet from said casing, an annular throat in said casing, a receiving chamber into which said throat opens and increasing in cross section from its top around to said outlet, a series of ,impact members in said throat in the path -divided into two portions one of which is pivoted to the other, bearings supporting 4 said shaft, covers, for said bearings, means connecting the pivoted portion of the casing to said covers, means connecting the pivoted portion of the casing to the shaft and means for raising the pivoted portion of the casing and simultaneously raising the caps on the bearings and the impeller and impeller shaft from its bearings.

18. A centrifugal pulverizer comprising in combination an impeller, a shafton which said impeller is-mounted, a casing for said impeller divided into two portions one of which is pivoted to the other, means for raising the pivoted portion of the cover, an areuate chute'ylocated in the stationary portion of the casing to partially embrace the impeller shaft and removable from said casing when the pivoted portion thereof is raised. v

19. .A centrifugal pulverizer comprising in combination an impeller disc, impeller blades detachably carried thereby, a shaft for said impeller, a casing enclosing said disc and blades and divided into two portions pivoted the one to the other, means for raising the pivoted portion of the easing, an annular guard surrounding the impeller shaft, an arcuate chute partially surrounding said shaft outside the annular,

guard, means on the respective portions of the casing for retaining said arcuate chute in position and permitting of the removal thereof when the pivoted portion of the casing is raised.

20. A centrifugal pulverizer comprising.

in combination an impeller disc, impeller blades detachably carried thereby, a shaft for said impeller, a casing enclosing said disc and blades and divided into two portions pivoted the one to the other, means for raising the pivoted portion of the casing, an annular guard surrounding the impeller shaft, an arcuate chute partially surrounding said shaft outside the annular guard, and stops on the respective portions of the casing for retaining said arcuate chute in position and permitting of the removal thereof when the pivoted portion of the casing is raised.

In testimony whereof, I have hereunto signed my name.

WI-LLIAM J. A. LONDON.

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