US1723917A - Apron drier - Google Patents

Description

Aug. 6, 1929. L BUCK 1,723,917

' APRON DRIER Filed Feb. l, 1926 '7 Sheets-Sheet 2 :ui "l f5) nu L. BUCK APRON DRI ER Aug. 6, 1929.

Filed Feb. 1', 1926 7 Smeets-Sheet 3 Aug. 6, 1929. L.. BUCK 1,723,917

APRON DRIER Filed Feb. l, 1926 Sheets-Sheet 4 Aug. 6, 1929.

L. BUCK APRON DRIER Filed Feb. l, 192@ 7' Sheets-Sheet 5 L. BUCK 1,723,917

APRoN DRIER y Filed Feb. l, 1926 7 Sheets-Sheet' ,6

M 1%, mw y. 1 l ,l ,uw m m m m m m m m m m uw m m mmmmm m mw/ mw, e EI uw ww l m m m w m m m m m m m m m Aug. 6, 1929.

Aug. 6, 1929.

l.. BUCK 1,723,917

APRON DRIER I Filed Feb. l, 1926 7 Sheets-Sheet 7 Sb I :i K Lfii: wenim m Patented Aug.r6,vl929. Y I l. l, Y, l' ,i UNITED :STATES PATENT OFFICE..

l l i i LUCIEN BUCK, or JAMATCA PLAIN, MASSACHUSETTS, 'ASSIGNOR' To B. F. STURTEVANT COMPANY, oF HYDE PARK, MASSACHUSETTS, A CORPORATION F MASSACHU- SETTS. y l

ArRoN DRIER.

Application filed February 1, 1926. Serial No. 85,102. t i

'111e present invention relates to apparatus shoddy rubber, although it is' to be underfor (l1-ying material and more particularly stood that the illustrated drier may be used to that type of drying apparatus knownas for drying other materials either of a apron driers in which .the material 1s dried fibrous or solid character, and that the inwhile it is being carried along on a convention may beembodied in other forms and 60 3.01. 0,. WML y I constructions. In these drawings, Figure 1 Heretofore driers of this type Vhave been shows the drier in front elevation; Fig. 2 is used with light-weight, loose packing ma an enlarged, longitudinal vertical section of terial over or through which the drying air the right-hand end of the apparatus showil 1o has been circulated atlow pressure. lVhere in Fig. 1; Fig. 3 is`an enlarged front eleva- 65 relatively heavy, close-packing material has' tion of the receiving portion l'of the drier, been sought to be dried on this type of apshovving the spreading mechanism; Fig. 4 is paratus, diflicult-y has been experienced not an end vierv of the same, partly in Vertical, only in properly supporting the heavy transverse section; Fig. 5 is a vertical,

Weight of the material but in forcing the transverse section through the apparatus', 70 drying air through the same to remove the Y* showing the top and bottom portions of oneI Vdesired amount of moisture. As a: .result it of the traveling conveyors and the several has been the general practice' to dry such air ducts for the lsupply and return of the heavy. close-packing materials in small lots' drying air land for the discharge of the same on shelves or trays where they stand exposed intovthe atmosphere; Fig. 6 is abottomplan 75, for-substantial periods ottime to the drying vieu', shoiving the perforated construction air. Such a process is necessarily slovv and4 of the conveyor and the Scrapers for removexpensive. Moreover, where a `plural1ty of ing the siftings from the top of the hot air aprons was employed, these were commonly boxes;` Fig. 7 is a top plan View at the end 25 located ina single chamber so that the mateof one of the hot air boxes, showing the per- 30 rial on the several aprons was all subjected.v Vforated construction of the -top of the air 'to the same circulating flow of air. The boxes and the serewonveyor for"dischargproper controlling. of the temperature, `hulng laterally the fsiftings delivered by the midity, and velocity of the air for the dlttcl'- Scrapers: Fig. 8 is a vertical, longitudinal 3o ent aprons, according to the character of the section showing the method of mounting the 35 material, and the stage or degree of dryness scraperspn the conveyor; and Fig: 9 is a attained, `was impossible. Furthermore, rear elevation of the apparatus,"showing the i 'where the air was compelled to pass prodriving mechanism for the conveyors.

gressively Ythrough first one apron after an- The illustrated drier comprises primarily` other and the'material carried thereby, the, a serles of superposed',underlapping, con? 90 cumulative resistance was such that the cirtinuously operating aprons or conveyors. culation ot the ldrying air was so greatly- The material is delivered upon one end of retarded that the proper drying of the Inathe uppermost conveyor and at the other terial it attained at all, was secured only by; end thereof is vdischarged by gravity upon long continued treatment. v the lnext .lower gonveyortraveling in the op- 95 Itvisthe object ofthe present invention'to posite directio ,ffrom 'which it is in turn` produce a drier ofthe apron type 1n u'hlch discharged upon another oppositely travelall classes of material may be dried to a'ny ing conveyor, and so on, the material dropdesired degree, automatically and continuping from one convevor to another and passbusty, 1ivitli a minimum of time and expense, ing back and forth, first in one direct-ion and 100 r and under properly controlled conditions as then in the other, until finally it is disfl to temperature, humidity andvelocity of the charged from the lowermost conveyor. drying air. f The drying of the material isy aecom- 'lo the above ends the present invention plishedy by means of currents of hotair deconsists in the drier hereafter described .and liveredlthrough air boxes underlyin the up- 105y more particularly definedin the claims. per section nof eah conveyor an having The accompanying drawingsV illustrate 'their top surfaces perforated to discharge `what is novv considered the preferred form the `heated air through. lThe conveyors or ot' the invention as embodied in a drying ap-` aprons are also perforated, and suitable parparatus particularly designed for drying titions and shields are provided so that air the predetermined conveyors and through next lower a ron.

f able indicatin and humidity.

A11 of the apparatus except the receiving the material carried thereby.

In order to insure an even distribution of Vmaterial and an even depth thereof over the conveyor or apron, a spreading or raking device has been provided at the receiving end of the apparatus which stirs or' rakes ,the material transversely on the upper or )receiving apron, a leveling gage limiting the depth ofthe material on the apron as it passes into the drier.

Means have also been provided at this portion of the apparatus for collectinr andcar- ,rying away any. liquid or material which may drop through the conveyor or apron adjacent to its receiving end.

The apparatus also includes means for removing'from the to s of the air boxes such material as may si t through the perfora-5 tions in the conveyors 'during the drying operation, these means comprising Scrapers upon the bottom surfaces of the aprons or conveyors/which scrape the siftings aloiig the top of theair boxes to their endsvwhere such material falls into a transverse trough in which a screw conveyor is operating to discharge-th siftings laterally from the :Lp-s paratus, whence they are returned onto the Fans and' eating units are provided: to-

. ether with suitable conduits for suppl v'ng eat-ed air Ato the several airboxes, an returning the same for reheating or discharg- )in into the' atmosphere dalnpers being suppliigd for controllin the flow of air and suitan controlling devices for regulating the temperature indicating ai end of thetopiconveyor and the discharge end df the bottom conveyor is enclosed Vby insulated walls in which removable closuresA are provided for the purpose of access to the interior of ,the drier.

' Referring now to the drawings, the `drierA thereimillustrated comprises six superposed conveyors or aprons, forming-an apparatus of such height that it is y located on two floors ofa factory. As shown inFig. 1, the two upper conveyors, together with the fans and yheater nlits, are located onthe upper. floor 1 1, while the remainin four conveyors are located directly beneat on the lower floor 12.AJ The upper conveyor 14 rec'eivs the moist material `at the left-hand end, as`

- viewedin Fig; 1 it being discharged from any suitable source of supply into a ho per 15 and thence on to the upper section o the conveyor. As the material moves to the right it comes beneath the spreading mechanism, to be described more in detail later, where it is spread or distributed uniformly `and evenly over the conveyor or apron.

A trough`or tank 19 beneath the conveyor lat this point serves to catch any free liquid or material which may drop through the apron.

After passing the spreader and the trough which are unenclosed, the material on the conveyor passesinto the -closed-in portion the drier pass over the air box 21 which extends beneath the upper section ofthe conveyor substantiall from one end yto the other. The top o this air box is provided with numerous 'small circularI holes 22 as shown in Fig. 7, through which the heated air is discharged directly against the bottom of theconveyor or apron. This also is perforated, being formedwith a large number of rectangular openings 23-as shown in F ig. 6, forming awmesh or rid construction to permit the air/filo pass trough and over the material supported on the conveyor.

During the traveling of the material across the drier or conveyor 14, a substantial amount of the moistureis removed, and when the material reaches the right-hand end of the machine it falls by gravity from the upper conveyor 14 to t esecond conveyor 25, being guided thereon by the inclined guides or chute 26. This second conveyor 25 travels .in the o posite 'direction to the top conveyor 14 an terial back-:to the left as viewed in Figs. 1 and 2, passing over an air box 27- similar to 21.

When the material on this second conveyor reaches the left-hand side of the drier, it is discharged into a hoplper 29 and chute 30 extending down throng the floory 11, and is delivered on to the third conveyor 32 trav- 4liyng to the right. It is again subjected to ing action from vthe air in box 34 and is then delivered successively to conveyors 35, 36 and 37, each having its own air box 3 8, 39 and 4U respectively. The .lefthand end ofthe conveyor 3'( extends beyond the enclosed portions of the apparatus, as

shown in Fig. 1, and from the end of this whereby the sections are pivoted or hingedVV upon a section of tubing or piping 43 whlch in turn is loosely mounted upon a shaft 45.

This shaft-comprises a tube or pipe 46 in carries the ma-v 1 y theV angle mounted upon the uprights 54 of the main structure` and upon the horizontal brackets 55 secured to such uprights. W'ooden strips 56 are provided at the out-er edges of the metal track 52 to serve as guides or abutments for the ends of the shafts 47 and I thereby prevent lateral displacement of the apron and wearing of the apron chain.

These tracks extend, nearly to the endsof the apron or conveyor and support both the top and bottom sections. VThe receiving end ofthe track is bent downwardly as shown at 58, (see'Fig. 2),`to insure the proper and easy engagement of the rollers therewith.

The conveyors or-aprons are supported at t each end upon sprockets of which one is power driven and the other an idler. Thus in `the topmost conveyor the left-hand sprocket 61 turns idly Wit-h the-movement of the apron. These sprockets are provided with teeth 62 .which enter between the side bars or ,links 5() an engage with i the rollers 49. Y'

Means are4 provided as l.is usual .in sprocket and chain constructionl for varying the distance between the sprockets, such means comprising, as shownA in Fig. 3. a

`movable bearing block 64 adjustable in the slotted guide 65 by means othe adjusting screw 66.`

The spreading orgdistributing mechanism for spreading the material uniforml over the first conveyor at its receiving end),I comprises two sets of vertical rods or teeth which are moved transversely to the feedtof the material by eccentric driving 'mechanism, the "two series being reciprocated simultaneously in op osite directions. This mechanism is best s ownin Figs. 3 and 4, the rods 68 being fixed in thebars 69 which are mounted to slide in the guides or bearings 70. The bars are reciprocated by means of the eccentrics 71 set 180 apart on the shaft 72, the eccentric straps 73, and the arms 74 pivotally connected to the vertical arms 75 fixed upon the bars 69,4 As thef shaft 72 is rotated through the gear 76, the

'bars 69 are reciprocated in opposite direc-- tions and the pins or teeth- 68 act lto spread the material uniformly over the apron, at

the same time breaking up any large lumps that may be present. A f

The leveler gage or gate 20 consists of a vertical section mounted upon the vertical support or channel 54 by bolt and slot-conH nection tol provide for vertieal adjustment' for the purpose of regulating the depth of material on the conveyor:

The air boxes for delivering the drying Nof' a workman.

air imlnediately beneath each perforated apron or conveyor extend beneath the upper section thereof nearly to its ends. As

shown in Figs. 1 and 2 these boxes are -dccplest at themiddle of the drier where they Hreceive their supply of heated air, the depth progressively diminishing towards each end.

In older to compel the heated air discharged .from these air boxes to pass through the conveyor and the material carried thereon, means are provided for preventing the escape of air downwardly on each side of the an' box or upwardly around the edges ofv the conveyor. The downward lower or inner edges of these shields are so close to the upper surface of the conveyor if not actually in contact therewith that any substantial escape of'air around the sides and over the top of the conveyor is prevent ed. -These shields also serve as guards to prevent `the material carried by the conveyor from falling oli' the sides thereof.

yThese partitions 77' `and the airboxes34, 38,

39 and 40 it will`be noted, divide the drier into a plurality of drying chambers, cach having its supply of heated air and a single loaded apron passing therethrough.

In order'to give access to the interior of the air 'boxes it occa-sion'should arise either for the purpose of inspection, cleaning, or repair, the removable closures 88 have been provided, each opening into a box and being of suflicient size to permit the passa-ge Heated air is supplied to the boxes from the fans and heaters, all of which for convenience are mounted on the second floor' of the installation. sshown in'the drawings, three of these heat-ing and fan units are provided, each unit supplying air to twojof the boxes. Thls unit 82 supplies heated air to the vertical supplyconduit 83 which communicates with the two upper boxes y2l and 27 at their middle. Unit 84 delivers air through its supply conduit 85'to box '34 and .the box` immediately beneath it, while unit.

86 supplies air through its conduit- 87 to the two lowermost-boxes.

Brovision is made for the recirculation ot the .heated air, or of such portion thereof as is desired, by means of return conduits cx tending froml above each conveyor or apron to its proper heater and fan unit. These return conduits are best shown in Figs. 1

'151. these conduits.

' Witha down-turned .edge or lip 107) and '5. For example, return conduits 89 and 90 return the air to the heater and fan unit 84, while conduits 91 and. 92 return the air to unit 86. These lconduits, as best shown in Fig. 5, are provided at their ends with short branch conduits 94 which pass through the side wall ofthe drier and terminate in the downwardly open ends 95. A damper 96 controls the return flow of air through `The discharge of air fromabove the conveyors .or aprons into the atmosphere is controlled by lmeans ofr'danipers 98 lin the discharge conduits 99, extending through the wall of the drier. By proper regulation of these dampers 96 and 98 the operator can recirculate yand discharge the desired amounts of heated air. A supply' of fresh air is provided through the inlet 100 in the Y suction conduit adjacent the fan, the closure 101 for which may be opened by the operator to the desiredA extent. Suitable indieating devices are provided to show the temperature and humidity of the drying air, such as wet and dry bulb` thermometers,

indicated at 102.

- lThe devices for removing from the top` of the air boxes the lliner material whic sifts down through the perforated conveyor comprises scraper blades mounted upon the lbottom faces' of the conveyor,which scrape hor push these siftings along the top of the A q lair box to the end thereof, where\ they f all f into a transverse trough or channel in which a screw conveyor is rotating and carries the siftings to the outside of the drier. These scrapers are best shown in Figs. 6 and 8 and comprise a pair of scraper blades 103 of libre or other suitable material secured to 40 the under side of the conveyor in a somewhat oblique or angular arrangement, with ltheir adjacent ends fastened together and slightly behind, in the direction of travel, their distant ends. These blades are free to move up and down to adjust themselves for slight variations in the level of the'top of the air box. The method of mounting these` scraper blades-is Vshown in Fig. 8 where arf angle' iron 104 is riveted to the bottomv face of the convefyor and is provided with vertical slots 105 pass'through the metal the fibre Scrapers 103. A

These Scrapers .are spaced at intervals on or the bolts which wear strip 106 and L each conveyor, and the end of the box toward which the conveyor moves is 'royiddd vide. an eas the scraper lades with the-top the-feed screw- 111 which is continuously ro'- t0 Plo. and gradual engagement of of the box. 60 The( opposite endof they box i. e. the end tated through the sprocket 112 by mechanism which is driven from the adjacent sprocket shaft. The siftings which are scraped along the top of the box by the scraper blades,fall down into the trough 109, along whicht-hey are carried by the feed screw until they drop into the chute 113 outside the drier. This chute extends down- Wardly and then inwardly through the wall of the drier and delivers the siftings onto the conveyor or apron next below.l

The driving mechanism for the several sprockets of the conveyors is shown in Fig. 9, which is a rear elevation of the drier. The power shaft 115 is driven from any -suitable source of power and through the pinion 116 drives the gears 117 and V118 in opposite directions. Sprocket chains 119 and 120 drive the counter shafts 121 and 122 respectively. Counter shaft 121 drives the sprocket shafts 123 and 124 and the intermediate shaft 125 from which is driven the sprocket shaft 126. 'Counter shaft 122 drives sprocket shaft 127 and intermediate shafts 128 and 129 from which sprocket ,shafts 130 and 131 respectively are driven.

The drier is enclosed in.an insulated casing made in the form of anels and bolted or otherwise secured to t e framework of the machine. These panels, as shown in Fig. 5comprise a thick sheet of insulating material protected on both sides by a thin metal cover.

The operation ofthe drier is as follows. The shoddy rubber or other material to be dried is delivered into the hopper 15 from which it passes to the upper section of tho top conveyor. As the material passes from beneath the hopper it is distributed or spread by rmeans of thespreading mechanism, the larger pieces or lumps being broken up. At the same time any excess -of liquid and some of the smaller particles of `material drop through the apron and fall into the tank 19. .l

The material on the conveyor then passes beneath" the leveler and enters the closed drier and passes over the perforated upper surface of the air box from which heated air at the desired temperature and humidity is flowing. under the action of the heater and fan.' There bein .no escape save throughl the apron and the material, the heated air passes throughthem, removing moisture from the material in vits passage. Such 'portion of this air will be permitted Jto escape into the atmosphere throu h box 99 as may be r uired to maintain the proper humidity, t e remainder being returned to the heater where it is again heated with additional fresh air and then returned to the air box. i

Meanwhile' the material has been assing throu h the drier `and when it reaciies the right and end, as the conveyor turns downwardly around ythe idle sprocket, is diss charged upon` the next lower conveyor by which it is carried. back through the drier in the opposite direction and again subjected to the action ofthe drying air. Any material which sifts through the-openings will be scraped along the top of thebox and finally discharged into the trough and thence bythe screw carried to the Chute lo 113 by which it is returned to the next apron below. f 1 l 'The material passes back and forth through the'drier falling from oney conveyor t onto the one next below, and in suchl trans- ]5 fer being thoroughly mixed and turned, with the result that all surfaces and allparticles of the material are exposed to the drying air. Finally the material is carried out o the y closed drier by the lowermost conveyor and 2o discharged in a uniformly and thoroughly dried condition. 4

By the above described construction both light and heavy material ma be driedcon! tinuously, automatically an expeditiously. VThe use of the perforated metallic conveyor and the tubular supporting members en.

ables heavy weights of`material 'to ,be carried, and by compelling the air to pass through such conveyor and tle material, relativelyclose-packing material may be thor-f oughly and uniformlyA dried. By the con- I tnuous` removal of any lsiftings which may passV through the perforated conveyor, cloggin or interference with the air supply is avoided and the drier may operate on long AstretchesL without the necessity of being periodically shut down` for cleaning.,

Since mechanism is provided which not only spreads and distributes the material evenly over the perforated conveyor but i. which serves also to break up and reduce any large' lumps, the drier is enabled to vhandle the materlal more elliciently bothas to time r uired and degree of dryness secured. y

he division of the device into separate chambers eachl havin its own supply of heated air and its sing e'loaded apron avoids the highAcumul'ative resistances ofj prior driers -where the air (passed through one apronafter another successively.,y Furthermore, the' temperature, humidity and velocity ofthe drying air applied to the material at different stages of the d ryin may be independently varied and contro ed to suit the varied conditions `at such stages, thereby increasing ,the speedof drying, desired rssy uality and rendering the vapparatus indepen ent of atmospheric conditions, such as excessive humidity in the summer time.

While the present invfention has been shown and describedin connection witha drier designed primarily fr'handlinga particular material, it is to be understood thatl it is not limited thereto, but may be used with other materials and the form and ar msuring the top and a bottom having a perforate middle f portion and imperforate marginal portions, 75

a perforate .traveling conveyor traveling through the chamber above the perforate A bottom, shields extending from Athe sidesfof the chamber close to the traveling conveyor whereby the air from the perforate bottom is compelled to pass through the perforate conveyor and the material carried thereby, and means for delivering heated air through the perforate bottom.

2. In an apparatus `of the character described, the combination with a chamber closed at its sides, of a rail on each side of the chamber, a perforate traveling con'- veyor, means for supporting the same com prising rolls at each side thereof traveling on said rails, an air box 'beneaththe conveyor and having a perforate top to discharge air against the conveyor, means extending fromv the sides of the chamber in close proximity to the top of the conveyor to prevent the escape ofair around the edges oft-he conveyor, and means for delivering air to the boxes. i

3. In an apparatus of thev cha/racter de. scribed the combination with a traveling perforate conveyor, of an air box beneath the. same,A a transverse trough at the end of the air box, a screw feed inA said trough, and a scraper attached to the bottom lof the conveyor to scrape any, material which-passes. throughthe perforate conveyor from the top of the, air box finto said trough.` 4. In an apparatus of the character described the combination with a plurality of superposed perforate traveling conveyors, air boxes beneathy the same, means for 'removing from the top of the air boxes any material which passes through the conveyors and dea vices for delivering such material onto a lower conveyor.

5,. In an apparatus of the character dei scribed the combination with' a traveling conveyor, of an air box located beneath the conveyor, and a scraper secured to the bottom of the conveyor to scrape the material from thetop of the Aair box, said scraper comprising a blade arranged transversely` of the con- .veyor, and means for supporting the blade having provision for vertlcal movement of the same relatively to the conveyor.

6.'In an apparatus ofthe character de# scribed .the combination with a conveyor, of under side thereof,

a'scr per mounted on the `said scraper comprising two blades obliquel arranged end-to-end with their adjacent endg through the conveyor,

lair beneath the conveyor, tached to the under surface o f the conveyor.

behind, in respect tothe direction of move-a ment, their distant ends, and means for securing the blades to the conveyor having provision for vertical movement of the blades c relatively to the conveyor.

7. In an apparatus of the character described the combination with a main cham ber, of .a plurality of superposed, looped,

traveling conveyors, the top and )bottom conveyors extending to points outside said lchamber for the receipt and the discharge respectively of the material to be treated, partitions in said chamber to form separated drying .chambers through which the conveyors carry the material, means for ,heating the air, conduits for delivering the same to each drying chamber, a return conduit from each chamber to' the heating means, an exhaust conduit from each chamber tothe at- `mosphere, and means under the control of the operator for controlling the lowpof air Athrough the return yandthe exhaust conduits of an drying chamber independently of an of t e other chambers.-

-8. n an apparatus ofthe character de.

for scraping the vmaterial from said surfaces topermit acess of the air to the conveyor.

9..'In an apparatus of the character described the combination withl a chamber having a perforate conveyor spaced abovefthe bottomof the chamber, means for supplying air to thechamber, a scraper mounted upon the bottom side ofy the conveyor and'engaging the-bottom ofthe chamber, means adjacent the end of the kchamber to discharge the scraped material vlaterally of the conveyor.

10. In anap aratus of the character described the com ination with a plurality of dryingichambers of a plurality of su'perposed underlapping pertorate traveling conveyors passing through the drying chambers, an air box beneath each conveyorhaving a perforate top toV permit the discharge of heated air through the perforate conveyor, each air box having an imperforate bottom, shields extending from the top of cach air box to the sides of the chamber, the top 'of the drving chamber for the conveyor immediately below lcomprising said imperforate bottom and said shields, and means for heated air to the boxes. i-

11. In an apparatus rof the character described the combination with a chamber closed at its sides of a rail on each side of the chamber, a perforate traveling conveyor, means for supporting the conveyor comprising rolls at each side thereof traveling on the rails, an air box ofless width `than the conveyor arranged beneath the conveyor and adapted to discharge air upwardly against the conveyor, means for delivering air to the air box, and shields extending' from the sides of the chamber in close proximity to Athe top of the conveyor lto prevent escape of air around the edges of the conveyor.

In 'testimony whereof I have signed my name to this specification.`

LUCIEN BUCK.

supplying

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