US1576362A - Apparatus for drying granular material - Google Patents

Description

'March 9 192e. 1,576,362

F. H. RosENcRAN-rs `APPARATUS FOR DRYING GRANULAR MATERIAL Filedoot. 15, 1924 4 sheets-sheet 2 March' 9 192s. 1,576,362

F. H. ROSENCRANTS APPARATUS FOR DRYING GRANULAR MATERIAL Fld Oot l5, 1924 4 Sheets-Sheet 3 March 9,1926. 1,576,362

F. H. RosENcRAN-rs APPARATUS FOR DRYING GRANULAR MATERIAL Filed oct. 15, 1924 4 shegts-sheei 4 UUUUUUUUUUUUUUUUUUUUU CAB Patented Mar. 5:5, lg.

UNITED STATES PATENT 'y QFFIC'E.

FAY HARRY ROSENCRANTS? OF KINGSWAY, LONDON, ENGLAND, ASSIGNOR TO :[NTER` NATIONAL COM'BUSTION, LIMITED, OF LONDON, ENGLAND.

AiPPARATUS FOR DRYING GRANULAR MATERIAL.

vApplication led @atelier 15, 1924. Serial No. 743,728.

To all aU/10m t 91mg/ concern Beit known that I, FAY HARRY Roslin'- onAN'rs, a citizen of the United States of America, residing atr Kingsway, London, lV. C. 2, England, haveinvented aA certain new and useful Improved Apparatus for Drying Granular Material; and I do hereby declare the following to be a full, clear, and eXac-t description of the invention, such as will enable others skilled in the art to which it appertainsfto make and use the same.

This inventionhas for its object to provide an improved apparatus for drying slack, or crushed coal or other fuel, and other more or less granular materials.

lVhile primarily intended for use in drying slack, crushed or line coal or fuel preparatory to pulverizing the` same for use in the furnaces of steam generators and in other furnaces, the method and apparatus according to this invention might be employed for drying other materials including powdered, pulverized or granular substances or materials.

As is known coal and other fuels contain moisture, and the percentage of moisture varies .in different classes or grades of fuel, and it is also well known that a fuel or other granular material must not contain more than a very limited amountof moisture to `permit of its being pulverized in a successful and economical manner. The methods and apparatus heretofore proposed or employed for drying fuel by means of hot gas or air while capable of dealing with fuel containing say 8 to l() per cent of moisture are not suitable for dealingeffectively with fuel containing higher percentages of moisture. It is the principal objectof this invention to provide a method and apparatus whereby fuel or other granular material containing high percentages of moist-ure can bc effectivelyk and properlydried,l the Asaid method and apparatus being furthermore capable of dryingr coarse to the most finely divided fuel or other material in a rapid and economical manner.

The apparatus for drying fuel (or powdered or granular material) according to this invention contemplates and embraces a plurality of plates, trays or the like carried by a. frame, casing or structure to which mo` tion in ther .i red direction can be given, several or the desired nun'iber of sets or series of such plates 0r traysvbeing providedand arranged in such a manner thatthe material delivered on to the platesL or trays of the first set and partially dried by the action of the apparatus is at the required time or times automaticallyremoved from the said plates or trays oft the i'irst set or series and ltra-nsferrcd or permitted to drop `on to the plates or trays of the next set or series, and so on from one set or series of plates or trays to the next until the complete drying operation has been effected, this transferring of the material from the trays or plates of one set to the trays or plates of the` next set being effected by means of mechanical scraping devices `past which the trays move during the drying process oroperation.

more, a mechanical spreader or spreaders is or are-provided for each set or series of plates or trays whereby the fuel or material delivered in a heap on toa plate or tray is nicely spread in a relatively thin layer on the surface'of the plate'or tray by means of the 'mechanical spreader as thetray is moving past the said spreader. When the trays with the material spread thereon have been given the .predetermined movement orv traverse in the casingor drying chamber (to,

which gases of comb-ustion, hot air, or other medium isadmitted, arimarily for the purpose of carrying away moisture and it may be also heating the coal), for instance when each tray of the first set is approaching the inlet for the material to be dried, one of the aforesaid mechanical Scrapers will automat-f ically. act to scrape the material olf the tray so that it falls therefrom on to one of the trays of the next or lower set, the trays in adjacent sets being preferably arranged in staggered relation so that the material can drop from a tray of one set through the space between the adjacent trays of the said set on to a tray of the next or lower set.

Fig. l ofthe accompanying` illustrative drawings shows in central. vertical section a constriilction of apparatus embodying the invention, suitable for the drying of slack or crushed coal. y

Fig.' 2 is a plan of the apparatus;

Fig. 3 is a horizontal section corresponding` to the line A A of Fig. 1.

Fig. 4 shows' the rotary feeding device in end elevation. n

Fig. 5 is an elevation of the lower or disn charge end of 'tba tf'r'ifiijratus.

Further- CII Fig. 6 is a horizontal section corresponding to the line B-B of Fig. 1.

Fig. 7 is a developed view showing some of the carrier plates and steam connections thereto.

- Fig. 8 is a detail view to a larger scale of the steam and drain pipe connections to the carrier plates. Y

Fig. 9 is an end elevation of one of the carrier plates.- y

Fig. 10'.,is a section corresponding to the line C-#Gcof Fig. 11.

, Fig. 11 shows one ofthe carrier plates in plan.

`.F ig. 12 is a similar view to Fig. 11 illustrating a modified construction of carrier plate. Y

Fig. 13 is a section corresponding to the line D-D of Fig. 12.

Fig. 14 isa similar View to Fig. 8 showing the s-team and drain pipe connections to the modified construction of carrier plates.

Fig. 15 is a vertical sectional elevation of the upper end of the drying apparatus illustrating a modification.

Fig. 16 is a horizontal section corresponding to the line E-E of Fig. 15.

Fig. 17 is a developed view showing the modified feedingV device illustrated in Figs. 15 and 16. n .y

Fig. 18 is a side elevation and Fig. 19 a plan of one of the perforated rocking plates of the modified feeding device.

Fig. 20 is a section corresponding to the line F-F of Fig. 19. y

The drying apparatus illustrated comprises a plurality of carrier plates 1 arranged in annular rows and secured at their inner ends, as by bolts, to the ou-ter ciroum` ference of a rotatable drum 2 mounted within a suitable fixed drum or casing 3.

The carrier plates are arranged in annular rows about the circumference of the rotary drum, there being any desired number of plates in each row, ten in the exampleillus# trated), and any desired number of these annular rows of plates being arranged one row above the other vin staggered relation and the said rows are suitably spaced apart inthe vertical direction with-the plates of each row also suitably spaced apart in the lateral or circumferential direction. The outer or free edges or ends of the carrier plates of all the rows lie preferably in close proximity to the inner circumference of the outer fixed drum or casing 3 this casing and the rotary casing 2 with its annular rows kof plates being preferably arranged in the vertical pos sition shown. y

The upper end of the outer fixed casing or drum 3 is closed by a suitable cover or plate 4 formed with an opening through which the material to be dried is fed by means of a rotary star feeder 5, see Fig. 4, or other appropriate feeding device, for example as An annular heating chamber 6 around the lower part of the fixed casing or drum 3 is fitted withy suitable coils 7 through whichl steam is passed. Air enters thek upper end of the heating chamber 6 and, after passing through the heater in doing which it becomes heated by Contact with the steam coils 7, the heated air enters the annular drying chamber in which the carrier plates 1 work bctween the fixed casing 3 and rotary drum 2 through an opening or openings 8 formed through the wall of the fixed casing 3 near the lower end thereof. A suction fan or the like connected to an air outlet 11 in the cover or pla-te 4 closing the upper end of the fixed casing or drum draws air. through the air heating chamber 6 and upwardly through the annular drying chamber so that it plays upon the material passing through the same on the carrier plates 1 and out through the opening 11 formed in the fixed cover or plate 4, into the suction conduit 12 of rthe fan or the like. y

The vlower end of the outer fixed casing` or drum 3 .terminates `in an inverted conical shaped extension 13 the bottom of which is fitted with a discharge device consisting of a wheel 14, fixed on the lower end of the central vertical shaft 15 which carries the ,rotatable drum 2, the said wheel being formed with radial blades that constitute pockets into which the dried material falls. ThisI bladedwheel 14 works over a fiat pate 16 that closes the end of the conical bottom 13 of the fixed casing 3 and a discharge opening 17 is formed in the plate l16 through which the dried material falls as the bladed wheel 14 rotates over the same. To prevent: entrance of cold air through the opening 17 into the casing a horizontal plate 17a fixed to the casing is arranged to extend over the bladed wheel 14 at a point directly over the said opening 17, the arrangement being such that material falling between the blades of the wheel 14 is carried below the fixed plate and drops ou-t through the discharge opening 17-as the wheel continues its rotation.

The vertical shaft 15 is mounted to rotate in bearings 19 at the top and bottom of the fixed casing 3`and the weight of the rot-ary drum 2 and the parts connected thereto is carried by a ball or roller bearing' 2O located above the casing and on which rest-s a collar 21 fixed to the shaft 15.

It will be understood that the particles of dried material entrained in the heated drying air are thrown by centrifugal force towards the wall of the fixed casing 3 as the hot air is flowing upwardly through the annular drying chamber.

The carrier plates 1 are preferably steam heated for which purpose they may each consist, as shown in Figs. 9, 10 and 11, of a hollow casting to which steam is'admitted, or, as shown in Figs. 12, 13 and 14, of a casting in which is 'ast a coil 22 of steam pipe, the inlet and outlet ends of which are exposed convenient for connecting' thereto a steam supply pipe 23 and a drain 24, see Figs. 7, 3 and 14. A number ofsteam pipes 23 corresponding to the number of carrier plates 1 in each row thereof, extend vertically within the rotary drum 2 alongside the wall thereof and a similar number of drain pipes 24 also extend vertically alongside the said steam pipes. rl"he steam pipes and the drain pipes are each provided with bent i branches 25 and 26 respectively corresponding in number and position to the annular rows of carrier plates and the branches of the steam pipes are suitably connected as by unions 27 to the steam inlets of the carrier plates or trays, the branches 26 of the drain pipes being similarly connected to the outlets of thesaid carrier plates. The arnangement of these connections can be clearly seen in -Figs. 7, 8 and 14. The upper ends of the vertical steam pipes 23 are connected to radial pipes 23 each fitted with a control valve 29, to a hollow steam distributing collar 30 embracing the vertical shaft 15 and rotating therewith, suitable glands 31at the top and bottom of the collar 30 being installed for the purpose of maintaining a steam tight joint. Radial ports in that part of the shaft embraced by the distributing collar 30 `place the interior of the collar and the steam pipes connected thereto in4 cominunication with an axial boring 32extending to the upper end of the shaft. A steam supply pipe 33 is suitably connected, as shown, to the upper end of the vertical shaft `15 so that steam is delivered, through the axial boring 32, and collar, 30 to the steam pipes and heating conduits of the carrier plates 1. In like manner the lower ends ofthe drain pipes 24 are connected through valve controlled radial pipes 34 to an axial boring 35 in the lower part of the vertical shaft 15, the lower end of which shaft is suitably connected, as shown, to a drain pipe 3G.

In the top cover plate 4 and circumferentialwall of the xed casing 3 appropriately arranged access doors 37 are provided where desired, the access door in the top cover plate 4 giving access to the valves 29 controlling the supply of steam `to the vertical steam pipes 23, the spindles of such valves extending through holes formed therefor in the plate 10 closing the upper end of the rotary drum 2, and an.accessdoor 38 in the conical extension 13 ofthe fixed casing giving access to the controlling valves 39 of thedrain pipes 24. 40 is a ymanhole formed in the conical extension of the fixed casing.

hilotion may be transmitted to the vertical wheel 41 driven from any suitablesource ofy power and ata predetermined speed. In the example shown `the shaft is driven by an electric motor 42 suitably mounted on a supporting structure'arranged above the fixed casing. Y f

The feeder or chargedevice 5 on thetop of the fixed casing 3 in the arrangement shown in 1, 2 and 4, isa device of a known kind adaptedto be rotated ata predetermined speed during the working of the appara-tus so that the quantity of charge of material adapted to be accommodated on eac-h carrier plate of the iirst or uppermost annular row will be delivered on to the said plate at the proper time, i. e., whenthe same is passing below the outlet from the, said feeding device.

ybut they may rise if required in order to avoid damage should a lump of coal or foreign substance become wedged under a spreader. VThe devices for scraping the material olf the carrier plates 1 also each consist of a pivoted metal arm 45, Figs. 3 and 7, upon the lower edge of which the carrier platesrub as they travel `under the same. The scrapersare pivoted by pins 45L to the casing 3 and rest directly upon the plates during the scraping operation, but

drop slightlyon to supporting pins 45b fixed y to the outer casing as they leave the plates. The metal arms 44 and 45const1tutingvthe mechanical spreaders and Scrapers may each `be made of a short length of metal bar so bent as to form a part adapted to be pivoted to the wall of the fixed casing and an arm or opera-tive portion that extends at a suitable angle from the said part as shown in Fig.

One of the mechanical spreaders 44 is provided atsuch a. position in relation to the inlet for the material it'roni the feeding device 5 that at a suitable interval after the first carrier plate l of the 'first or uppermost annular row (with itsheap of fuel or material delivered thereto from the feeding device) has passed clear of the feeding device., its leading edge will come under the spreader which will nicely spread the heap of material over thefsurface `of the carrier plate. A similar spreader is lprovided for each Aannular row of carrier plates carried In thek yapparatus yunder' y notice the feeding device 5 is driven from thel by the rotary drum 2. scrapers 45 for removing the layer of more or less dried material fromthe carrier plates of one annular rowto the carrier plates of the nextv annular row are Alocated in such a position that each carrier plate approach# ing and coming in contact with the scraper will haveA the spread and more or less dried material thereon removedl lfrom it bythe scraper just prior tothe vcarrier plate arriving at the position when the next ch. rge or quantity of material will be delivered thereon in a heap either through theinitial feeding device 5 at the top of the apparatus or from `a carrier plate of an upper annular row.

The underside-s of the carrier plates'l may be plain as in Figs. 9, 10 and 11 or formed With ribs or ridges 50in order to increase the heating surface in contact with'gthe hot air, as shownin Figs. 13'and 14. o

In the modified arrangement of feeding device shown in Figs. 15, '1G and'17, a series of perforated plates 51 formed itmay be of expanded ine-tal, as shown, are substituted for or arranged above the toprow of earrier plates 1. 'lhe material is fedon to these perforated plates through a feed chute 52, the thickness of the layer deposited thereon being regulate-d by the adjustmentof a regulating plate 53, seeFig. 17. lVith this arrangement the air as `it leaves the annular drying chamber has to passthrough the layer of Wet material on the perforated plates 51 and such material consequently constitutes ai filter for removing the dust from the said air and renders the action of the drying apparatus more satisfactory and complete.

Y ing strips at the free edges ofthe plates 51.

'lheangle iron support 61. consists of a ring having; an interruption vat t-he point Where the perforated plates 51 ,tilt inorder to dump the material on to the carrier plates V1 beloiv. From Fig. 17 it can be seen that the perforated plates 51 are supported by the angle iron ring 61 in a horizontal position until the point of interruption is reached when the plates tilt and the material falls off the same. The leading end of the angle irony support 61 is bent downwardly as shown in Fig. 17 so thatupon continued movement of the rotary drum the plates 51 are caused to .ride up the downwardly bent Similarly the angle'iron andl assume the desired horizontal position prior to receiving a fresh charge 'if material` from the feed chute 52.

In order to prevent a rush of-air through 'lie gap formed at the point Where the per forated plates 51 tilt about their trunnions, an air baffle in the form of a. bent metal plate.. 62 is provided `over the row of perforated plates at' the said point, see Fig. 17.

From the foregoing it will be seen that the improved system and apparatus according to this invention Will veffect the drying yof material in a rapid and continuous manner by-a number of steam heatedcarrier plates or trays 1 arranged in sets one below another and with which spreaders 4.4 and Scrapers L15 eo-operate for the purposes hereinbefore mentioned, the spreading of the material on the plates or trays 1 ensuring that the moisture inthe material shall be thoroughly dried outand this thorough drying being further ensured bythe fact that the more or lessr dried material removed from the plates or trays of one set by the action of the-hereinbefore mentioned scraper or sera-pers is turned over or redistributed and is thereafter again spread upon the plates or trays of the second or lower set and so on according to the number of sets of platesor trays provided in the apparatus.

Modifications might be made in the details of construction and arrangements .above set forth Without departingfrom the main features y of the invention, for example the heating medium may consist of hot gases of-combustion yfrom a furnace or other suitable source.

llVhat I claim is 1. In a drying apparatus, a stationary casing for hot air, carrier plates yfor the material spaced apart and arranged one above another in staggered relation inthe casing, means for feeding the material onto the top carrie-r plates intermittently in predetermined quantities, means for spreading the material on the carrier plates, and means for subsequently scraping the material oft' the carrier plates so that it descends in the casing by gravity.

2.111 a drying apparatus, a stationary vertical casing for hot air, a rotary drum mounted in the said casing, carrier plates for the material secured to the rotary drum -and spaced apart and arranged one above another in staggered relation in the casing, means for feeding the material onto the top carrier plates intermittently in predetermined quantities, means for spreading the material on the carrier plates, and means for subsequently scraping the material offr the carrier plates so that it descends in the casing by gravity.

3. A drying apparatus as set forth in claim 2, the said means for spreading the material on the` carrier plates comprising arms pivoted to the stationary casing and extending over the said plates, and stops which limit the downward movements of the said arms.

'4. A drying apparatus as set forth in claim 2, the said means for scraping the material off the carrier plates comprising arms pivoted to the stationary casing and adapted to rest on the plat-es, and stops which limit the downward movements of the said arms when not resting on the plates.

5. A drying apparatus as set forth in claim l, the said carrier plates being provided internally with steam chambers for heatingthem, pipes for supplying steam to the steam chambers, and pipes for draining the steam chambers of water.

6. A drying apparatus as set forth in claim l, the said carrier plates havingrexternally corrugated undersides which are exposed to the hot air in the stationary casing.-

7. A claim l, the said stationary casing being pro-A vided with an inlet for hot .air at lits lower part below the carrier plates and an outlet for hot vapor at its top above the carrier plates.

8. A drying apparatus as set forth in claim 2, the said stationary casing having a conical vlower end portion and a flat discharge plate provided with an outlet opening for dry material, and a discharge device revolving with the said drum and working over the said flat plate and its opening.

9. A drying apparatus as set forth in claim 2, the said stationary casing having a conical lower end portion and a flat discharge plate provided with an outlet opening for dry material, and having also a flat plate spaced apart from the discharge plate; and a discharge wheel revolving with the said drum and provided with arms which work betweenthe flat plates and over the said outlet opening. p

l0. A drying apparatus as set forth in claim 2, the said carrier plates being provided internally with steam chambers, a

main steam supply pipe mounted concentric with the said drum, a series of vertical steam distributing pipes communicating with the steam chambers of the carrier plates which are directly above one another, radial steam pipes connecting the main steam pipe with the `said distributing pipes, and pipes for drying apparatus asset forth in.

draining the said steam chambers of water.

11. A drying apparatus as set forth in claim 2, the said carrier plates being `provided internally withl 'steam chambers, a main drain pipe for water mounted concentric with the said drum, a series of vertical drain pipes communicating with the steam chambers of the carrier plates which areV di rectly one above another, radial drain pipes v connecting the vertical drain pipes with the said main drain pipe, and pipes for supplying steam to the said steam chambers.

l2. A drying apparatus as set forth in claim 2, the said means for feeding the material onto the top carrier plates comprising a series of pivoted perforated plates which support the wet material in the path of the dust at the outlet part of the hot air casing, said perforated plates being ar-V ranged to revolve Vwith the said drinn and provided with means for tilting them one after another automatically at a predetermined point to discharge the material onto the carrier plates.

13.' A drying apparatus as set forth in claim 2, the said means for feeding the material onto the top carrier plates comprising a series of pivoted perforated plates which support the wetmaterial in the path of the dust at the outlet part of the hot air casing, said perforated plates being arranged to revolve with the said drum and provided with means for tilting them one after another automatically at a predetermined point to discharge the material onto the carrier plates, and astationary baffle plate arranged over the perforated plates at their point of discharge and While they are tilted.

14. A drying apparatus as set forth in claim 2, the said means for feeding` the material onto the top carrier plates compris-

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