US2108609A - Whizzer separator and mill - Google Patents

Description

Feb. l5, H933. R, F. OMARA 2,108,609

v WHIZZER SEPARATOR AND MlLL A A Filed April 15, 1935 s sheets-sheet 1 Ww Il 3f I :I--fw ff? 3g @f4 I3 I rilllll 529:7?

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f WHIZZER SEPARATOR AND MILL Filed April l5, 1935 3 Sheets-Sheet 3 Patented Feb. .15, 1938 UNITED STATES PATENT OFFICE WHIZZER SEPARATOR AND MILL Richard F. OMara, Chicago, Ill., assignor, by mesne assignments, to Combustion Engineering Company, Inc., a corporationof Delaware Application April 15, 1935, Serial No. 16,443

11 Claims.

drawn from -the mill in suspension in an air` stream.

In a mill of the'type to which this improved separating apparatus is applied, the material is ground or pulverized by means of a plurality of rollers or similar devices and sufficiently fine material to be carried in suspension is lifted out in an air stream passing. through the mill and afterwards separated from this air stream by means of a cyclone separator or other suitable apparatus. The separating device which forms the particular subject matter of this invention is interposed directly between the outlet of the mill and the conduit through which the material is withdrawn in suspension, and is used to reject the heavier particles from this air stream and selectively determine the neness or grade of material that may be lifted from the mill. Briefly described, this .separator comprises a rotary deflector or whizzer, closed at its central portion and comprising a plurality of outwardly projecting vanes between which the suspended pulverized material must pass before emerging from the mill material outwardly by centrifugal force and cooperates with the surrounding casing wallsor a stationary deiiector carried thereby to reject the heavier particles-passed downwardly into the mill for further treatment. The faster the speed of rotation of the rotary deflector the finer the material that will be rejected in this manner, and by suitablyv controlling the speed of the rotary deflector the grade of material that emerges from the mill in the-air stream may be accurately determined within certain limits.

The principal object of this invention is to provide an improved grinding and separating apparatus of the type .briefly described hereinabove 55 materials su'ch as paint pigments,

housing. This rotary deiiector tends to throw the Other objects and advantages of this invention will be more apparent from the following detail description of one approved form of apparatus constructed and operating vaccording to the principles of this invention.

In the accompanying drawings: y Fig. 1 is a central vertical section through one approved form of the improved grinding and separating apparatus.

Fig. 2 is an elevation showing the complete circulating system of which this improved separating unit forms a part.

Fig. 3 is a partial horizontal section taken substantially on the line 3--3 of Fig. 1. i

. stream; the conduit D through which the airv stream is propelled by fan C into the cyclone separator E wherein the suspended material is deposited; and the conduit F lfor returning the air stream, or a portion thereof; to the mill A.

As shown in Figs. 1, 2, and 3, the mill A comprises the upright casing l, usually cylindrical, which is centered about the central vertical axis :c and is supported by the frame 2. The central vertical shaft 31s rotatable in bearings l and 5 in the supporting structure 6 and carries at its lower end a beveled gear l which meshes with a pinion 8 on the drive shaft 9 projecting horizontally from the supporting frame 2 and driven from any suitable source of power. vThe spider Ill carried at the upper end of shaft 3 supports a circular series of roller-carriers `l I, each pivoted in spider I0 at l2 so that the grinding rollers i3 which are `supported by carriers lI-for free rotation may swing radially toward or from the shaft 3. When this assembly is rotated, the rollers I3 will swing outagainst the stationary bull-ring I4. "The material rollers I3 and bull-ring i4 so as to be crushed or pulverized. The plows I6, also carried by! the rotating assembly, pick up material that falls through the bottom of the casing and deliver it back up between the grinding elements.

The fan C draws air into the mill housing from the annular manifold l'i through inlet openings I8 and thence upwardly through the mill housing, this air stream picking up in suspension such material as is sufficiently finely pulverized to be carried by the air stream. In the usual system, this air stream passes directly from the mill housing through outlet conduit l!! into the fan C and is then projected through conduit D into the cyclone separator E.

According to the present invention, this suspended material must first pass through the sparator B which is interposed between the upper end of the mill and the outlet conduit i9. The separator casing comprises substantially an upward extension of the mill casing l and consists of a top or closure plate from the central portion of which the outlet conduit i9 extends, an upper cylindrical shell 2l preferably of somewhat larger diameter than the mill housing l, and a downwardly and inwardly tapering conical shell 22 which connects the lower portion of shell 2| with the upper edge of mill housing l. A gear casing 23 is supported centrally within the conical casing 22 by means of a plurality of radially extending plates 24, these plates being positioned vertically so as to present a minimum of obstruction to the air stream flowing upwardly through this casing. The rotary deector or Awhizzer 25 is carried by the vertical shaft 26 journaled in gear casing 23 about the central vertical axis ir. Shaft 2B is rotated, through suitable gearing mounted in the casing 23, from the horizontal drive shaft 21 extending through one side wall of casing 22 and driven by means herel inafter described.

The rotary deector 25 comprises a closed central disk-like portion 28 from which extend a plurality of radially projecting vanes or blades 29. The outer ends of these vanes are beveled inwardly and upwardly as indicated at 30 and rotate in close proximity to the lower surface of a downwardly and outwardly projecting annular conical deector 3| carried by the horizontal extending annular top plate 32 which is secured to the inner surface of casing wall 2| in any suitable manner, for example by the angular ring 33. The inner portion of annular plate 32 preferably projects over the adjacent upper and outer surface of the vanes 29 as indicated at 34.

These cooperating rotary and stationary deectors operate much the same as the corresponding elements as disclosedin the patent to Cook 1,783,357, granted December 2, 1930 for Me-Y chanical separator.lv The rotary deilector 25 imparts a whirling motion to the air within the separator casing, the heavier particles of material carried by the air stream being thrown out against the casing walls or the stationary deflector 3| and thence rejected downwardly through the separator casings and back into thei mill. The only upward path for the air stream is between the rapidly rotatin'g vanes 29, between the central disk or apron 28 and the outer stationary deiiector and casing walls, and vonly finely pulverized material can be lifted in suspension between these vanes. All of the material above a certain size will be thrown outwardly against the stationary deector 3| and thence thrown downwardly to reenter the mlll for further treatment. I

It has been discovered that, within certain rather wide limits, the faster the rotation of the aioaeoo deector 25 the finer the material that will be rejected and returned to the mill. Consequently, by suitably varying the speed of rotation of this deilector or whizzer, the grade or ineness of the material that is withdrawn in suspension from the separator can be selected and regulated quite accurately. In the form here shown, a constant speed electric motor 35 (see Fig. 2) suitably supported/outside of the separator housing drives the shaft 2l through a suitable change speed mechanism. As here shown, a Reeves variable speed transmission 36 is driven from motor 35 through the belt gearing 3l and drives shaft 2l through belt gearing 38. By means of this variable speed gearing, or any other suitable device, the deiiector 25 may be rotated at any one of a multiplicity of selected speeds, and a corresponding grade of ground or pulverized material will be delivered from the mill and separator combination hereinabove described.

By means of this apparatus, pulver-ized material of greater and more uniform fneness may be obtained, and simple and accurate control of the degree of this neness is possible by simply adjusting the speed of rotation of the whizzer. This rotary deilector is self-cleaning and is especially adapted for handling sticky substances such as paint materials, especially when used in direct combination with the mill, as herein disclosed. The finely divided particles of certain paint pig.- ments, such as lithopone, or white lead, have a strong tendency to adhere to one another and to the exposed surfaces of a separator, even though the materials are quite dry. As a consequence the ordinary type of separator having closely spaced parts and relatively small passages, such for exampleas the double-cone type of separator with small inlet and outlet openings, will soon clog up and become ineffective. The same is true with the type of separator disclosed in the Cook patent hereinabove referred to, from which certain elements of the present separator have been adapted, when this Cook separator is used apart from the mill and in the form disclosed in the' patent. It will be noted that in the present combination certain of the cones of this Cook separator have been eliminated, and the single conical shell now used has a large lower inlet and return opening corresponding to the full diameter of the mill housing and in fact forming acontinuation thereof. Furthermore, the vibration imparted to the assembly by the rotating elements of the mill and separator serves to agitate the sticky materials and minimize the adherence of the material particles to the separator structure. As a result these materials can be `very effectively handled and classified, the larger and heavier particles falling freely back into the mill while the ner materials are carried out in suspension in the air stream, without clogging the apparatus. For these reasons the mill-separato; combination will operate efficiently for long periods of time without requiring attention or cleaning.

While this improved separating mechanism is hereinabove disclosed in combination with a roller mill of the well known Raymond type, it will be apparent that it could be combined in similar manner with other forms of mills. In Fig. 4 is shown an impact mill A of well known type comprising a plurality of swing-hammers 39 carried by horizontal shaft 40 driven by motor 4|. The material to be pulverized and dried is introduced from hopper 42 by means of rotary feeder 43 into the mill housing M wherein it is pulverthrough conduit F carries out the pulveri'z'ed material in suspension through outlet I6 and thence into separator B. The remainder lof the circulating system may be the same as shown in Fig. 2.

The modication shown in Fig. 5 is much the same except for the fact that Fthe inlet to separator B is connected with the top or peripheral portion of the mill-housing M, the mill being of the same type shown in Fig. 4.-

. This improved grinding and separating unit is quite simple and compact, and in most instances will eliminate the necessity of subjecti ing the pulverized material, to a separating procvthe mill and outlet conduit and comprising a laterally closedi separator casing forming substantially an upward extension'of the mill casing,v a rotary deilector mounted for rotation about a central vertical axis Within the Aseparator casing, said deector comprising a closed central portion and a plurality of spaced apart outwardly projecting vanes extending into proximity to the casing walls, an annular stationary deflector carried by the casing wall and closely overlapping the outer end portions of the vanes so that the only path for the upwardly owing air stream is between the rotating vanes, and means for rotating the rotary deflector.

2. In combination with a mill comprising a casing havingan outlet, grinding mechanism in the casing comprising rotary members and means for rotating the same, means for feeding material into the milLand means comprising an outlet conduit for lifting pulverized material from the 'mill in suspension in an air stream, a separator interposed betweenr the mill and outlet conduit .and comprising a laterally closed separator casing forming substantially an extension of the mill casing, a rotary deflectc.` mounted for rotation about a central axis within the separator casing, said deflector comprising a closed central portion and a plurality of spaced apart outwardly projecting vanes extending into proximity to the casing walls, an annular stationary deilector carried by the casing wall and closely. overlapping the outer end portions of the vanes so that the only path for the upwardlyowing air stream is between the rotating vanes, a motor for rotating the rotary deflector, and variable speed gearing interposed between the motor and deector without aiiecting the speed of the grinding mechanism.

3. In combination with a mill comprising an upright casing having an outlet, grinding mechanism in the casing comprising rotary members and means for rotating the same, means' for feeding material into the mill, and means comprising lan outlet conduit for lifting pulverized material from the mill in suspension in an air stream, a separator interposed between the mill and. outlet conduit and comprising a separator casing forming substantially an upward extension of the` mill casing, a rotary deflector mounted for rotation about a central vertical, axis within the separator casing, saidV deflector comprising a closed central portion and a plurality of spaced apart outwardly projecting vanes having upwardly and inwardly beveled outer ends, and. an annular stationary conical deector carried by the separator wall and closely'overlapping the outer end lportions of the vanes, and means for rotating the rotary deflector.

4. A grinding and separating apparatus comprisinga vertical casing substantially symmetrical about a central vertical axis, a grinding mechanism in the lower portion of the casing rotatable about the vertical axis, means for rotating the grinding mechanism, an air inlet to the lower portion of the casing, means for feeding material to the vgrinding mechanism, an outlet conduit leading from the upper end of the casing through which pulverized material is lifted in suspension in an air stream, a deilector mounted in the upper portion of the casing for rotation about the central vertical axis, said deflector comprising a closed central portion and a plurality of-spaced apart outwardly projecting vanes extending into proximity to the casing wall, an annular stationary deflector carriedv by the casing wall and closely overlapping the outer end portions of the' vanes so that the only path'for the upwardly flowing air stream is between the rotating vanes. and means for rotating theirota'ry deflector.

5. A grinding and separating-apparatus comprising a vertical casing substantially symmetrical about a central vertical axis, a grinding mechanism in the lower portion of the'casing rotatable about the vertical axis, means for rotating the grinding mechanism, an air inlet to the' lower portion of the casing, means for feeding material to the grinding mechanism, an outlet conduit leading from the upperend of the casing through which pulverized material is lifted in suspension in an air stream, a 4deilector mounted in the upper portion of the casing for rotation about the central vertical axis, said deflector comprising a closed central portion and a plurality of spaced apart outwardly projecting vanes ex-4 tending into proximity to the casing wall, an

annular stationary deflector carried by the casgrinding mechanism, an air inlet to the lower portion. of the casing, means for feeding material tothe grinding mechanism, an outlet conduit leading from the upper end of the casing through which pulverized material is lifted in suspension in an air stream, a deflector mounted in the upper portion ofthe casing for rotation about the central vertical axis, said deflector comprising a closed central portion and a' plurality of spaced apart outwardly projecting vanes having upwardlyand inwardly beveled end portions, an annular conical deflector overlapping the outer end portions of the vanes, and means for rotating the rotary deflector at various selected speeds without affecting the speed of the grinding mechanism. l p

'1. A grinding and separating apparatus comprising a vertical casing substantially symmetrical about a central vertical axis, a grinding mechanism in the lower portion of the casing rotatable about the vertical axis, means for rotating the grinding mechanism, an air inlet to the lower portion of the casing, means for feeding material to the grinding mechanism, an outlet conduit lea'ding from the upper end of the casing through which pulverized material is lifted in suspension in an air stream, a deflector mounted in the upper portion of the casing for rotation about the central vertical axis, said deiiector comprising a closed central portion and a plurality of spaced apart outwardly projecting vanes having upwardly and inwardly beveled end portions, an annular stationary conical deflector carried by the casing wall and overlapping the outer end portions of the vanes, a motor for rotating the rotary deflector, and variable speed gearing interposed between the motor and deector.

8. In combination with a mill comprising an upright casing having an outlet, grinding mechanism in the casing comprising rotary members and means for rotating the same, means for feeding material into the mill, and means comprising an outlet conduit for lifting pulverized material from the mill in suspension in an air stream, a separator interposed between the mill and outlet conduit and comprising a laterally closed separator casing forming substantially an upward extension of the mill casing, a rotary deector mounted for rotation about a central vertical axis within the separator casing, said deflector comprising a closed central portion and a plurality of spaced apart outwardly projecting vanes,

and an annular conical outwardly and downwardly projecting stationary detlector carried by the casing wall in substantially lateral alignment with the vanes and having an inwardly projecting upper extension closely overlapping the outer end portions of the vanes, said stationary defiector closing the space beyond the ends of the vanes so that the upwardly flowing air stream must pass between the rotating vanes, and means for rotating the deector.

9. In combination with a mill comprising an upright casing having an outlet, grinding mechanism in the casing 'comprising rotary members and means for rotating the same, means for feeding material into the mill, and means comprising an outlet conduit for lifting pulverized material from the mill in suspension in an air stream, a separator interposed between the mill and outlet conduit and comprising a laterally closed separator casing forming substantially an upward extension of the mill casing, a rotary deflector mounted for rotation about a' central vertical axis within the separator casing, said deector comprising a closed central portion and a plurality of spaced apart outwardly projecting vanes, and an annular conical outwardly and downwardly projecting stationary deector carried by the aioaaoa casing wall in substantially lateral alignment with the vanes and having an inwardly projecting upper extension closely overlapping the outer end portions of the vanes, said stationary deflector closing the space beyond the ends of the vanes so that the upwardly owing air stream must pass between the rotating vanes, and means for rotating the deflector at various selected speeds independently of the speed of the grinding mechanlsm.

10. A grinding and separating apparatus comprising a laterally closed vertical casing substantially symmetrical about a central vertical axis,

a grinding mechanism in the lower portion of the casing rotatable about the Vertical axis, means for rotating the grinding mechanism, an air inlet in the lower portion of the casing, means for feeding'materia to the grinding mechanism, an outlet conduit leading from the upper portion of the casing through which pulverized material is' lifted in suspension in an air stream, a deflector mounted in the upper portion of the casing for rotation about the central vertical axis, said deflector comprising a closed central portion and a plurality of spaced apart outwardly projecting vanes. and an annular conical outwardly and downwardly projecting stationary deflector carried by the casing wall in substantial lateral alignment with the vanes and having an inwardly projecting upper extension closely overlapping the outer end portions of the vanes, said stationary deiiector closing the space beyond the ends of the vanes so that the upwardly flowing air stream must pass between the rotating vanes, and means for rotating the rotary denector.

11. A grinding and separating apparatus comprising a laterally closed vertical casing substan- JVtially symmetrical about a central vertical axis,

a grinding mechanism in the lower portion of the casing rotatrble about the vertical axis, means for rotatil g the grinding mechanism, an air inlet in the lower portion of the casing, means for feeding material to the grinding mechanism, an outlet conduit leading from the upper portion of the casing through which pulverized material is lifted in suspensionv in an air streama deflector mounted in the upper portion of the casing for rotation about the central vertical axis, said deilector comprising a closed central portion and a, plurality of spaced apart outwardly projecting vanes, and an annular conical outwardlyancl' downwardly projecting stationary deector carried by the casing wall in substantial lateral alignment with the vanes and having an inwardly projecting upper extension closely overlapping the outer end portions of the vanes, said stationary deflector closing the space beyond the ends of the vanes so that the upwardly nowing air stream must pass between the rotating vanes, and means for rotating the rotary deector at various selected speeds independently of the speed of the grinding mechanism.

RICHARD F. OMARA.

'. Pacont No.2,1085609:`

CERTIFICATE oF- ooRREcTIoN. i l

' February 15, 1953-. RICHARD F. 01mm. 1

\ Y .Itis hereby certifiod that error apps-ars :Lid tvshev printed spocsiiceltzloii` of the above numbered patent requiring qcm-action as follows: .Page 5, first column, linea 61 65., and 66, claim 2,. strike out the words "withcuvaffectin `the svpeed of the grindlng mechanism g Aam that the aid Lotteria Patent should be reatiwiththris correction therein thatithe saine may conform tou-the record hof' the case in the Patel-1t Office, l

signed and-@enea imk 29ml day of March, A. n. 1958,

- -Henry Arsdale, (Seal.) Acting' Commissioner of Patents.

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