US2468871A - Rotary drier - Google Patents

Description

G. P. FORNI ROTARY DRIER May 3, 1949.

Filed June 17, 1944 v12 Sheets-Sheet 1 IN V EN TOR GEORGE FORNI Arroz/@YJ I G. P. FORNI ROTARY DRIER 2 Sheets-Sheet 2 Filed June 17, 1944 INVENTOR. GEORGE P. F 01am' Ml TTOENEYS Patented May 3, 1949 ROTARY DRIR G'e'orgef-P-.f For-ni, Emeryville, Calif! Application Junefl, 1944, Serial No.v 5412810 3 Claimsr (Cl. 344-137 )7*k littlespace.Y By reducing the space through l which the material passesV in direct ratio` to the shrinkageoi the material,` Icause the dryer to operate moreeiliciently;

Ilprovide atubular dryer that rotates about a longitudinal axis that is inclined at an angle sufficient to-cause the material togadvance along the dryer during the dryingoperation. The tubular dryer has sections that are progressively reduced in diameter. I make use of novel means forfadvancing `thema-teri-al from a` larger tubular section into a smaller*y one, this `same means tumbling the material-as it moves throughthe dryer in order that all parts may be subjected to Aheatfor drying purposes. The device is simple inconstructioniand the drying tube-itself with the materialA lifting means consists of but one rotatingfpart.

Other `objects and advantages Will appear in thefollowingspecification, andthe novel features of the devicefwill. befparticularly pointed out'inthe appended claims.

My invention is illustrated in the Iaccon'ipanyingdrawingsfjformingea Apart :ofc this application, iny which;

Figure -1 is a; longitudinal :section-through the entire device;

Eigurex 2 is a transverse section .takenalong the line2"2 I-of Figurefl;

Figure 3 eis va transverse sectionitakem along` the line -33 of VFigure l;

Figure-Lisatransverse section taken alongtheline 4-s-4 'of Figurei 1;

Figure; 5 is an isometric: viewflshowing -a -diagram of the rot-atingfrtube{and-f Figur-e-is @a transversesecti'on taken along the' lineart-45:A of- Figure 1.

Whilel I have l shown zonly :the .preferredforms of my-,invention;I it: shouldibe understood that' Various schangesuon modifications -rnayberemadeV Within vthe@ -sGoreyofctheeappendede' claima'uwith#I "1 adjacent to the' ArimY an'dmisjr 'rotatablyy carried,"-

out; departing from the spirit" and 'fsc'ope'v of'tlie'VILK invention'. l

InJ carrying outl my; invention I" provide#an'4` elongatedtubeor' cylinderzin'dicated "generally at A.` Thistiilee'maybe"oitanylength desired 'and I iindth'at vinthe drying' jofjgarbage it shouldbe' about one hundred feet long: Theztubehas outer" supporting rings Iaudit-mountedthereon and the diameters' lof the rings-'fare equal.l Figure'l showsA ther ring I "supported-*by idle" 'roller sets 3 which in turn, are pivotally`rnoi 1r1'ted"atY ll'on" a plate 5. The plate ris supported 'by alconcretie'4v base E.' The-ring2 is'carried'fbyjroller sets, T' which arelof the same v'construction' as"the"roll"er sets-3and the roller sets 1 `are supported ona con' crete base` 8. The' axis ofthev drying4 tube; indi` catedN by Ithe dot dash' 1ine^9`l is .,inclinedI so jtliat the'entrance end 'Illjoftli'e'tubeis djsposed'at a! suicient height 'alcovel the 'exit' end''ll'. so that the material will move along the .cylinderas'th'e latter isv rotated: TheI angleof"inclinationcan be altered to suit the particular requirements:

The entrance'diameter'of thetub'e'is'preferably six feet. The'isection Al";of'trie'tubejhaswthel` same entrance diameter; while'the central 'sec-1 Theend-section A3 "has'azz'three: foot diameter.'` y

tions-per minute by" the" mechanism' shown in\` Figure-1. A` ringj-jgear I3"is"mount-edlf'on the" central "section Aandgmesheswitl'i avpinion I4` which in turn; lis rotated '."byl a" gearA reducing` mechanism yindicatedl 'generallyl at "l 5 v'and :opere atively connected `to^ani electric 'motor' I6"." type'of tube rotating'mechani'smwill;suffice;

The tube is prevented*'fromimovin'g longitud-i9 L, nally-in the* direction "of itslo'wer end by'fa. thrust. Wheel Il" that bears against 'th'e'f ace? of the `ringfg` by the vplate 5 and"concrete'basef Ifdesiredl., additional thrust Wheelsmaybeused;

The lentrance end I 0 of fthe' tube" projects. into a chimneyj I8"-th-'at"'has .asnioke-,stack' |9. come 50"-"municating therewith. A *valve or damper' Icontrols the flow, oihotgase's' throughthe smokef stack;` Aprotectinglflange'21"is mounted on ther tube^or`cy1inder adjacentjto'l the? entrance. endl' V andfis rotatablyjreceived ingan annularlfgro'oiiefA 55 2 2 i Vfor thel i purpose ""'of I 'preventing any" heated gases from' escaping into the atmosphere before they pass into the smoke-stack.

Any m-eans for feeding the material to be dried may be used and I have shown an oscillating hopper 23 in Figures 1 and 2. The hopper 23 is in the form of a half cylinder with a closed end 24 and an open end 25 that delivers the material, such as garbage, into the entrance end of the tube. Pairs of legs 2S and 21 are pivoted to the hopper and to a base plate 23 which in turn is mounted on a concrete base 29.

Means for reciprocating the hopper comprises a cam rotated by a motor 3| and a gear reducing mechanism 32. The cam 3u contacts with a cam follower 33 which is attached to the hopper. A stopI 34, preferably of rubber, is disposed in the path of the cam follower 33 and prevents it from contacting with the cam when the lowest point of the cam is reached. The cam 30 moves the hopper to the right while coil springs 35 move the hopper to the left. The material is placed in the hopper and is fed into the -entrance end of the tube in a uniform stream due to the reciprocation of the hopper.

The novel means for lifting the material as it moves from one section of the tube to a smaller section, comp-rises a series of steps or cup-shaped portions BI and B2. Figure 5 shows the step or pocket BI as having a width equal to a half circumference of the tube and as having a radius equal to the radius of the entrance end of the tube. The step Bi extends into the central section an appreciable distance and has inwardly extending shoulders 36 that are disposed opposite to each other. When the step Bi is at the lowermost portion of the tube during the rotation of the latter, the material in the section Ai will gravtate into the step Bi which in reality is an extended portion of the section AI. tended section Bi will tend to remain at the bottom of the section, even while the latter is rotated. The material will move along the wall during the rotation until it comes to the shoulder 36. At this point the shoulder will engage With the material and as the shoulder is carried upwardly by the tube, it will tumble the material onto the section A2. Continued rotation of the tube will eventually cause all of the material in the section Al to be lifted by the rotating shoulders or vanes 35 into the central section A2.

The same process is repeated when moving the material from the section A2 into the end section A3. Here the step B2 receives the material from the section A2 when the former is at the bottom of the tube. The extended section or cup-shaped portion B2 has the same radius as the central section and the shoulders 3l will lift the material into the end section A3. The portion Bl is disposed 180 from the portion or pocket B2.

The material as it is dried will shrink and the purpose of the gradually reducing diameters of the sections is to compensate for this shrinkage. If the exit end of the tube were the same diameter as the entrance end, the flame issuing from the burner 3S and the hot air produced by the name, would now along the upper portion of the tube and not be brought into intimate Contact with the material for drying it. By reducing the diameter of the tube a number of times through a number of sections, the drier material even though occupying less space will be brought into Contact with the hea-ted air because this material is moving through a tube section that has a much smaller diameter. The

The material received in the extrance novel feature of the invention is to move the material into tube sections of progressively decreasing diameters by a mechanism that has no moving parts and is in reality a permanent part of the tube itself.

At the exit end of the tube A, I show a housing 39 that has an endless conveyor 40 for carrying away the ash and any unburnable material, such as tin cans and the like. A door 4l gives access to the housing and to the conveyor. A sealing flange i2 mounted on the tube and rotatable in a groove i3 in the housing prevents the flame and the hot air from escaping and causes the flame and the hot air to pass into the tube.

From the foregoing description of the various parts of the device, the operation thereof may be readily understood. I have explained the greater part of the operation of the invention during the description of the structure. The tube may be rotated at any desired speed and the vanes or lifters 36 and 3l may be of any desired shape and size. The steps or cup-shaped portions Bi and B2 receive the material even though it is very fine because the material tends to move along 'the bottom of the tube. The vanes raise the material and drop it so that it passes through the path taken by the heat. The steps prevent the material from slipping along the bottom of the tube from the entrance to the exit end Without being lifted. The steps may be likened as extensions of the tube sections from which they extend and they permit the material to move from the larger sections into the enends of the smaller sections without piling up on any annular shoulders.

l'n certain cases the material, when dried, might expand rather than shrink and in these cases the tube would be reversed so that the entrance end would be the small one and the exit end, the large one. The burner 38 creates a temperature of about l500 Fahrenheit, which is suiicient to burn the dried garbage as it passes through the end section A3. The garbage may be delivered into the tube at the entrance end in a Wet condition. The garbage will be thoroughly dried before it reaches the small end A3 and then 'the dried garbage will be burned. In fact, the burning garbage at the exit end will furnish additional heat for drying the garbage entering the device and in certain cases it is possible to shut down the burner 38 by closing a valve fifi after the device has been set in operation because the burning of the dry garbage dries the wet garbage to a point where it can be burned.

I claim:

l. In a rotary dryer, a rotatable tube inclined downwardly from the inlet to the outlet end, means for rotating the tube for causing material received at the inlet end to gravitate toward the outlet end of the tube, means for directing heated air through the tube, said tube being divided into a plurality of interconnected sections of progressively reduced diameters from the inlet to the outlet end, the axes of all of the sections being aligned with the axis of rotation of the tube, each section except the outlet end section having semi-cylindrical portions of the same radius as its respective section extending an appreciable distance into the next smaller diameter section, the said next smaller diameter section having a cut out portion communicating with the semicylindrical portion of the next larger section, the overlapping of the semi-cylindrical portion into the next smaller section forming a pocket with a semi-circular step at its juncture with the smaller section and two longitudinally extending and diametrically opposed shoulders that extend throughout the length of the pocket, each pocket causing its longitudinal shoulder to lift the material thereon and empty it into the next section when the rotation of the tube is in a position to dispose the pocket in the upper tube half, the material in dropping from the shoulder by gravity, passing through the tube interior and thus being heated.

2. In a rotary dryer, a rotatable tube inclined downwardly from the inlet to the outlet end, means for rotating the tube for causing material received at the inlet end to gravitate toward the outlet end, means for directing heated air through the tube, the tube being divided into a plurality of interconnected sections of progressively reduced diameters from the inlet to the outlet end,

each section except the outlet one having semi- -cylindrical portions of the same radius as its respective section extending an appreciable distance into the next smaller diameter section, the said next smaller section having a cut out portion communicating with the semi-cylindrical portion of the next larger section, th-e overlapping of the semi-cylindrical portion into the next smaller section forming a pocket with a semicircular step at its juncture with the smaller section and two longitudinally extending shoulders that extend throughout the length of the pocket, each pocket causing its longitudinal shoulder to lift the material thereon and empty it into the next section when the rotation of the tube changes the angle of the shoulder for dropping its material into the next smaller section, the material passing through the heated air during its drop from the shoulder.

3. In arotary dryer, a rotatable tube inclined downwardly from the inlet to the outlet end, means'for rotating the tube rfor causing material received at the inlet end to gravitate toward the outlet end, means for directing heated air through the tube, the tube being divided into a plurality of interconnected sections of progressively reduced diameters from the inlet to the outlet end, each section except the outlet one having semicylindrical portions of the same radius as its respective section extending an appreciable distance into the next smaller diameter section, the said next smaller section having a cut out portion communicating with the semi-cylindrical portion of the next larger section, the overlapping of the semi-cylindrical portion into the next smaller section forming a pocket with a semi-circular step at its juncture with the smaller section and two longitudinally extending shoulders that extend throughout the length of the pocket, each pocket causing its longitudinal shoulder to lift the material thereon and empty it into the next section when the rotation of the tube changes the angle of the shoulder for dropping its material into the next smaller section, the material passing through the heated air during its drop from the shoulder, the adjacent pockets in the tube being angularly disposed with respect to each other.

GEORGE P. FORNI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,422,039 Dean July 4, 1922 1,649,839 Marston Nov. 22, 1927 1,720,786 Fasting July 16, 1929 1,898,776 Horn et al Feb. 21, 1933 1,992,705 Lellep Feb. 26, 1935 2,082,970 Overman June 8, 1937

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