US2199015A - Combined drier and separator - Google Patents

Description

Patented Apg. 3o, 1940i* vKurt 'roenmlaerm washington,

Combustion Engineering signor to Inc., New York, N. Y.

N. Y.. as-

Companr,

Application December 15, 1937, Serial No. 179,8-03

The invention relates to apparatus forv disintegrating and simultaneously drying wetmaterials in the vpresence of drying gases and thereafter 'separating the comminuted driedv material 5 fr Omthe gases. n

The general object of the invention is toprovvide-improved apparatus for -performinggthese A Qperanons..

" Morespecifically invention relates to appa-Iv which the drying-l'iisir'itegraty f .-ing lapparatus comprises a memberv rotatingv l0"v ratus ofthis lsort in abouta vertlcalaxis, the disintegrated dried ma-j terial being thrown out tangentially 5 at' the peg riphery of thismember. In such devicesia's here# tofore arranged material are ledto a cyclone separatorior-con-J centrator by means of a material-bearing gases into the cyclone atl its upper circumference in such a direction as vtoA Y Preferably, this channel is made senil-circular in 2()v cause a whirling orgyratory motion. Asa result of such gyratory motion the gases give upy the vparticles of the dried material, which then collects at the lower part of the conicalv portion 'of the cyclone, while the gases having given up y their burden of solids are taken off centrally.

Such apparatus and its operation entails somev disadvantageous featuresand includes some elements which I have `found unnecessary. The objectv of the present invention may therefore be more specifically said to be the provision of apparatus of this sort in which a portion of the apparatus formerly necessary is dispensed with and in which the action is such as .to avoid some loss of energy and therefore to be more economical.

The -invention will be described in connection with the `drawings accompanying this specification. In these drawings Fig. 1 illustrates one form of the invention in vertical central section,

2 is a section on line rl- 2r` of Fig. 1; Fig. 3H

is a View similar to that of Fig. 1 showing a varia- .tion .and also showing some auxiliary apparatus, and FigA- shows a further form of theinventive idea. -11 n Referring first 55 centric circles. Other pins 4 are arrangedin 'the :gases .conveying the; ldried ductwhich deliversthe ing I6 yto the form of the invention illustrated in Figs. 1 and 2, the drying-disinte, grating portion of the apparatus, generally desig- (m34-34) y l f circies'conntric'wish the first `set and aiternatv ing-with them,';these pins being secured -to a sta-v y tionary part." Inf-theform illustrated they are Asecured to the top cover 5. of the drier and extend downward from it. Alsosecureu 'tothe Snert l. is 5v 'a plate 6 which 'is preferablyfsflightly largerthan the'opening Tmrh'e annul'axplatej '.Thefplate `6 is placed on the'shafi',,slightly-above-Stlie'annui g lar: plate 2 so that 'thereisr-anopening ltlleft eircwmferenc e are fanblaqes s: Extndingdcwn-Y means'- Siich 'as thei spider! Mannir '-.theaxmul'er` plate .2 fis `securedl'to the sl bracketsjl,l.g v 1 v f ,v

v The stationary platefifisv secured to Ian ,annular race or 'channel I 2` which encompasses..p1--,en y circles the.A drier. and extends somewhat below it.v

cross section or at least of roundedform. I Thisillustrated, for example, it is secured to the beams IS-I 3, and from its lower end is hung'the'c'yclone 25 casing I4. The plate 5 rests on its upper end and the bearings l8-'I8, in which shaft I 'is supported, is carried by the brackets I8aJ-I8a which are secured to plate 5. Adjacent to its center the memberl I5 which is provided with the feed openthrough which the wet material .to be dried as well as the drying gases are supplied. v YThe inner endv of this channel I6 is so disposed that it discharges the material on the plate 8. .35 The element I5 embraces the shaft I but is vslightly spaced from it'v as at I1. This permits -air to Acirculate between the `shaft and the ele- 'ment, thereby keeping the shaft from becoming heated and transmitting heat to the'shaft bear- 40 ings, I8-'-I8. I9 is Aa'pulley by means of which the shaft is'rotated. v

The cyclone. comprises' the usual two parts, namely, theupper cylindrical portion Ila.v and the lower downwardly Mb. In the form of the apparatus illustrated in Fig. 1 this cyclone is a separator, i. e., it coml pletely separates the solids fromv the gases, the solids collecting in the lower .part of IIb 'and' being removed through the 'connection 20.`

I'he separated. gases are taken out of the cycloneby means of the tube', ZI which extends axially upward from the bottom', terminating within the sleevev 9. Preferably a short lsmall7 f diameter cylindrical length 23 Vis inserted beu,

between' the two. Secured 'to plate-.2? at. its outer -10` amena-pr am plate' carries the 30 Y tapered or conical portion- 45 Cil tween the bottom` of the conical part IIb Yand the oitake 20, this length 23 enclosing but being spaced from tube 2|.

the cyclone.

. 'I'he action of this apparatus will be'obvious but may be brieiiy stated as follows: Thev material to be dried, together with the drying gases, is introduced at I6, the material falling on the plate 6. The 'rapidrotation of this plate causes the material'to be thrown 'outward into the nestv fan blades 8 cause a rapid circulatory motion of the gases leaving the rotating element. lThese gases encounter the annular channel I2 and are by it deflected downward into the cyclone, Without losing their rotary motion.v 'I'his rotary motion causes the .separation of the solids from the gases in the usual way, the solids being taken oil' at the bottom and the gases being taken oi at the upper central portion.

The-space 6a between the annular plate 2 and the plate G'permits a local circulating of the A fan 22 is placed in the outlet end of 2|, serving to draw the gases out of drying gases, these gases entering the sleeve 9 at its lower -part and going upward to this gap and so passing again through the drier. The excess gas leaves through the tube 2|.

It will be clear that by the arrangement described I save the extra material that is required if the drier is separately housed from' the cyclone and the material-bearing gases are led by a tubular duct from the drier to the cyclone. Moreover, and more important, the gyratory motion imparted to the gases by the fan blades 8 is not destroyed, but the gases are delivered directly into the cyclone with this motionA intact, which there results in the separating action. In the former arrangements any gyratory motion of the gases and material leaving the rotating 'part ofthe drier lwas lostin the tubular duct conveying them to the cyclone.

In the form of the invention illustrated in Fig. 3 the drier is identical witlr that described in connection with the form of Figs. 1 and 2. The cyclone, however, is here only a concentrator. In other words, the material is here not `completely separated from the gases but is merely concentrated near the bottom of the conical part and is carried off from this part by means of some of the gases which flow out withthe dried material and serve to carry it. The duct for the flow of this current of gas carrying the solids is shown at 24. 'This current, with its burden of material, is delivered into the'separator cyclone 25 where the separation from the gases is completed, the material being taken off at the lower part of the separator and the cleaned gases being removed at the upper part through the outlet 26. Preferably the gases are recirculated and this is done by means of the channel 21,'further hot gases being added as required through the incoming branch 28. Excess of gases is taken off by means of the vent 29, preferably from the central part of the outlet channel 26 Where these gases are cleanest. A fan 30 assists in removing these excess gases.

In connection with this form of Fig.v 3, I further illustrate the usual arrangement whereby some of the dried material is added to the fresh or raw and relatively very wet material coming from hopper 3l. As much of the completely driedmaterlal as necessary is added and the i'emainder is taken of! through the branch 32.

This is in accordance with well known practice andthe mixture of returned dry material and raw wet material is delivered by the mixing screw 33 into the channel 21 and so to the charging opening I6.

'Ihe arrangement of Fig. 3 is particularly useful in cases where the incoming raw material is very `wet whereas the form illustrated in Fig, l, with out the use of any dry return, '.isladapteldl yforjthe treatment of material that can be fed directly without any admixture of dried product. It will,

.. however, be understood that the form of Fig. 1

with its separator cyclone can also be used when very wet/materialis tobe treated, in which case, however, the dried material which is to be mixed with theincoming raw material must be raised vto the top of the apparatus by means of some form of conveyor. In th form of Fig. 3 an additional conveyor becomes unnecessary as the gases can carry the dried material directly from the lower part ofthe concentrator tothe elevated portion. 1

In Fig. i there is illustrated a form of my invention in which the cyclone is placed in an inverted position and above the drier-disintegrator.A ,The raw materialis fed in throughthev hopper l31a, the required proportion of Itreated material, being added throughl branch 32a,

lwhere such admixture is required. The'screw mixer delivers the mixture to .the plate 6,' whichv in this case rotates with plate 2a. The 'shaft la extends'downward 'and is' driven by means of pulley I9, as will be obvious from an inspection'- of the drawings. The stationary pins 4 are in this case carried, by the stationary 'plate 5awhich has a circular central opening from which .the sleeve 9a extends upwardly. A closing bottom cover 5b is usedto close up the lower end of the apparatus. The cyclone in this 'case is of the concentrator type, some of the drying gases, together with the comminuted dried material, beingtaken off at the tapered upper end of the cyclone through channel 24a, which deliversl f these gases to the cyclone separator 25a. Controlled amounts of hot gases for drying the material are introduced through the tube 2Ia extendingaxially downwardly ending within the sleeve 9a. In this form local recirculation of the drying gases is effected by gases entering the upper end of sleeve 9a passing. through the lower end of this sleeve into the drier and outward between the pins.

plate, and disintegrating means arranged about and outwardly from the center of said plate, all j so arranged that gases and material to be dried are directed from the center of said plate out-` wardly to said disintegrating means and leave the latter tangentially; a cyclone separator coaxial with the drier and located below and adjacent thereto; an annular channel surrounding the drier and connected to the upper part of the cyclone vto receive the gases and material discharged tangentially from the drier and to deliver them while whirling to the lcyclone separator` about its upper portion, vthe lower portion of the cyclone being frusto-conical for the reception of' 2. In a disintegrating drier having a horizon tally disposed plate mounted on a vertically rotatable shaft, means for feeding gases together with material to be treated to the center of said plate, and disintegrating means arranged about and outwardly from the center of said plate, all

' a vent tube extending downwardly from the upper f s'o arranged that gases and material to be dried are directed from the center. of said plate outwardly to said disintegrating means and leave the latter tangentially; a cyclone separator coaxial with the drier and located below and adjacent thereto; an annular channel surrounding the vdrier and connected to the upper part of the cyclone to receive the gases and material discharged tangentially from'the drier and to deliver them while whirling'to the cyclone separatorabout its upper portion, the lower portion of the cyclone being frusto-conical for the reception of the material to be separated from the gases; and

central part of the cyclone and projecting through a lower wall portion thereof for removal of a portion of the drying gases.

3. In apparatus as defined in claim l, said plate comprising an imperforate disk forming a partition between the drier and the upper portion of -the cyclone and having a central opening therein communicating with theinterior of the latterya yspider securing said disk to said shaft:v fan blades mounted near the periphery of said disk; and a second plate secured to said shaft in superposed relation to said disk above the opening therein to` receive the material fed into the drier, whereby a recirculation of the drying gases from the cyclone through the opening m said mst diskand the space between the two disks may take place. i

4. In apparatus vdefined in claim l, said plate comprising a disk forming the ybottom of the drier and having a central opening therein communicating with the upper portion of said cyclone separator; a spider securing said disk to said shaft; fan blades mounted near the circumference of said disk; a second disk slightly larger than the opening in said first disk secured to said shaft in superposed relation to said first disk for receiving ,the material fed into the drier; a sleeve extendingdownwardly into the c'yclone from the edge in the opening of said first disk surrounding the upper end of said vent tube for preventing solids passing out with gases owing through the latter; and means to remove the dry material vfrom the lower end of said cyclone..

5. In a disintegrating 4drier having -a horizontally disposed plate mounted on a vertically rotatable shaft, means for feeding gases together with material to be treated to the center of said plate, and disintegrating means arranged about andoutwardly from the center of said plate, all so arranged that gases and material to be dried are directed from the center of said plate outwardly to said disintegrating means and leave the latter tangentially; a cyclone separator coaxial with the drier and locatedbelow and adjacent thereto; an annular channel surrounding the .drier and connected to the upper partl of the cyclone to receive the gases `and material discharged tangentially from the drier and to deliver 'them while whirling to the cyclone separator about its upper portion, the lower portion of the cyclone being frusta-conical for the reception of the material to be separated from the gases; and a vent tube extending downwardly from the upper central part of the ,cyclone and projecting through a lower wall portion thereof for removal of a portion of the drying gases; a sleeve extending from the frusto-conical portion of said cyclone and surrounding said vent tube, said vent tube projecting through the wall of said sleeve; and means for removing dried material from the outer end of said sleeve.

6. In a disintegrating drier having a horizontally disposed plate mounted onv a vertically ro- Atatable shaft, means for feeding gases together `with material tore-be treated to the center of said connected to the cylindrical portion of said chamber to receive the gases and material discharged tangentially from the drier andto deliver them while whirling to the cylindrical section of said chamber; and means for withdrawing the dried 'material and gases from said chamber.

v KURT TOENBFEIDI.

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