US1834095A - Separator - Google Patents

Description

- Dec. 1, 1931. FRASER l s lfig SEPARATOR Original led April 27, Sheets-Sheet l INVENTOR 45 M 7km G. H. FRASER Dec. 1, 1931.

SEPARATOR ginal Filed April 27, 1925 4 Sheets-Sheet 2 Ori Fly. .5

INVENTOR Dec. 1, 1933. G. H; FRASER 1,834,095

' SEPARATOR Original Filed April 27, 1925 4 Sheets-Sheet 3 INVENTOR G. H. FRASER Dec. 1, 1931.

SEPARATOR Original Filed April 27, 1925 4 Sheets-Sheet 4 INVENTOR I Patented Dec.a 1, 1931 rams enema norm rnasnn, or Bnooxmnv, ivnw Yoax snrana'ron Application filed April 27,1925, Serial u 20,033. Renewed Jul a, man.

This invention relates to air separators or dust collectors for separating and collecting fine material, and aims to provide'im provements in such for use with mills of-the ring and roll or other type and for air separators used in connection therewith or otherwise, and to provide an improved pulverizing and separating machine.

Heretofore a plurality of planetary rolls have been revolved about the interior of a crushing die to pulverize material between the peripheral crushing faces ofvthe rolls and the inner crushing face of the die. Centrifugal force incident to'the speed of the planet ary travel of the rolls has been used as the crushing force. Air has been circulated in below the ring and up through the crushing zone to float out the fine materialto permit its separation and to return the air'in an endless circuit through the mill and separator.

Revolving plows in front of the. rolls have lifted fallen uncrushe'd materialup to. the crushing zone. A chamber above the crushing elements has permitted coarse particles to fall as the fine particles have gone .through.

a sinuous passage around a deflector and depending lip to the air outlet. A fan connected at its-suction side to the air'outlet and at its blast side to piping communicating with a remote dust collector has been used to with-. draw and convey the fine material to its destinationQ A return pipe for the cleaned air is connected between the exhaust of the dust collector and ,a tangential return chamber surrounding tangential air inlets beneath the crushirigzone of the mill to return the air with a whirling efl'ect below and inwardly of the ring. Heretofore, in returncurrent pulverizing and separating machinesenclosed in an outer casing affording an annular passage for'the separating current, for example; as shown in my Patent No. 1,499,516, dated July 1, 1924, such casing has enclosed as part of the our- 4 rent path a dust chamber below the crushing .chamber and through which'the separating J current has flowed under the'open. bottom wall of the crushing chamber to return through an opening under such wall, and there has been no closed uncrushed material 'munication between the uncrushed material and the dust chamber or between the separating current and the dust settling in the dust chamber, aflording above such wall aninward passage for the separating current and around said wall a currentlessdust passage to the dust chamber. My invention aims to provide improvements especiall applicable to air separators for use with mi ls operating on this principle, and in pulverizers for use with return current air separators, and to provide an improved combined mill and air separator for pulverizing and separating material by this method. g I To this end in carrying out the preferred form, of my invention I provide an lmproved air separator preferably havin between its material dropping opening and 1ts dust chamber means for ret'aining and sustaining unseparated material below the separating current, and means for tossing such sustained material into such path, and an outer casing preferably enclosing or enveloping the crushing cham er and crushing elements and exposing the main frame and driving mechanism, and I provide an inward current passage above such retaining means, and ourrentless downward dust passing means around said retaining means, preferably as ducts communicating between the return air chamber of the separator and the space below the crushing chamber for returning air ben'eath the latter without passing the air through the dust chamber, and I provide a closed communication preventing material sustaining wall spaced below the crushin chamber and above the dust chamber and a fording a bottom wall for the inward current passage for the returning current above such wall, andaround it currentless downward i dust passages to said chamber, preferably as fine ways or conduits for conducting fines out of and below or across the zone of the returning air and past and without the crushing and driving elements to beneath the latter, and I provide improved means for filtering or cleaning dust laden air, and a variable separating or settling chamber and adjustable bellows like transverse cross chamber wall above the crushing chamber for varying the fineness of theoutflowing dust, and an adjustable damper for varying the air outlet, with the aim of effecting pulverization in the crushing chamber, selection and fineness of dust above it, separation of the dust immediately around it, unmolested collection I of .the dust below and out of the zone of the tom wall spaced below said dropping opening and afi'ording below said crushing elements and above said bottom wall'an inward return current passage, and affording around said wall a currentless downward passage for such dust, and affording below said return current inlet and above said dust chamber a communication preventing wall for preventing communication between said coarse material and said dust-chamber, and I preferably dispose said wall under and'enc'ircled by said cleaning means, and I preferably provide current means revolving concentric 'of and above said dropping openingfor circulating a separating current upthrough and down around and in under said crushing chamber and above said dust chamber in the form of a vortex ring, and I preferably provide material uptossing means below such current means and above said wall and encircled by said cleaning means for uptossing such material in the up-leg of such vortex path of-said crushing elements, and I preferably provide said crushing chamber with a.

variable cross chamber partition atfording a variable selecting chamber below said outlet "for varying the area of the up-leg of 'such vortex ring and varying the fineness of dust floating from said crushing chamber.

And I also preferably provide two co=operating crushing faces, the upper one the usual concave or cylindrical upwardly extending die face against which the material is crushed by impact. and pressure and the lower one a contiguous nearly flat but preferablyslightly downwardly and inwardly tapering annular attrition face or shelf on whichthe primarily crushed material from i above may be frictionally further reduced,

. roll; ring of cleaned returning current and into the tion; and

able construction a concentric of and opposite this disc, and a regulating feed collar around this pipe and mounted on a diaphragm balanced to move with variations in the suction at the egress part of the fine chamber to vary feed with such variations. V

And I preferably provide an axially ad- {us'table feeding screw conveyor for impeling more or less feed from the feed hopper to thefeed pipe, and an inclined and referably pivotally adjustable discharge e ge beneath one length of conve or flight thereof to graduate the discharge rom the conveyor into the feed pipe to approximate a uniform stream instead of an intermittent dropping.

And I provide various other features of improvement in the construction, arrangement and operation, all of which will be hereinafter more fully set forth with reference to the accompanying drawings, in which Fig. 1 is a side elevation, partly in vertical axial section, of the preferred form imlproved pulverizer and separator;

ig. 2 is a plan view thereof partly in horizontal section on the planes of the lines 22 in Fig. 1; Fig. 3 is a horizontal section thereof on the planes of the lines in Fig. 1; Fig. 4 is a small side elevation thereof as arranged for elevating or conveying the dust laden air to a remote int for separation by my improved dust co lector, the parts being broken out to show them partly in section on the planes of the lines H in Fig. 5;

Fig. 5 is a similar plan view thereof partly in horizontal section on the planes of the of my lines 55 in Fig. 4;

' Fig. 6 is an enlarged axial section of the Fig. 7 is a vertical section showingmy improvements as applied to a revolving ring .roll mill having'my improved spiral case, and direct outwar acting springs,.and reversely acting stop chatter springs;

Fig. 8 is a Fig. 9 is a vertical axialsection of my improved air separator alone.

Referring'to Figs. 1 and 2 of the drawings let A indicate the ring, B the rolls, C the main frame or casing, D the drive, E the feed entrance, and F the-fine outlet, of a pulverizing separating machine.

These parts mayflbe of'any usual or suitording a crushing chamher and crushing elements therein which can cooperate to pulverize coarse infed material plan view thereof partly in seci and separate and withdraw pulverulent material. ,Either or both of the crushing elements may revolve about a vertical or other axis, and centrifugal force or other means may be used for generating the crushing force necessary to pulverize the material between the reciprocal coacting crushingfaces of these elements.

till

' terred form 'referring As shown the ring A is an annular die mounted in the frame or base C and having a vertical cylindrical inner crushing face disposed about a vertical axis, and the rolls B revolve ina horizontal plane about this axis and each has a vertical cylindrical peripheral crushing face running against and coacting with the crushing face of the ring to crush material between these faces. A plualityof planetary rolls is preferably used, fear being shown, and each being movable radially of the ring and free to revolve on its own axis as it tracks on the inner face of the ring. Impelling plows or agitators G revolve with the rolls to raise and throw the material to be crushed up in front of them and on to the face of the ring in advance of the bight of the rolls. A revolving head or carrier H sustains and propells the rolls and plows around in a crushing chambar I. The crushed materialpasses from the crushing chamber into a settling or precipitation chamber J from which pieces are returned to the crushing chamber and finer pieces passed to a selecting chamber K from which the oversize is likewise returned and the fineness desired passes through the dust outlet TL. Air is usually used to withdraw the dust from the crushing chamber and is circulated by a suitable blower as the fan M through an endless circuit N comprising a dust collector-for separating the dust and a return passage for returning the air with-.

in the crushing chamber withlwhich it com-' municates through a plurality of tangential air inlets or duets O at the side of this chamber remote from the chamber J. this endless circuit comprising all said chambers and the blower chamber and the dust collector or separator and such communicating or external passages as are desirable or necessary to connect and includethese to permit depositing the dust where desired and continually reusing the air.

My invention provides various improvements in devices of this character, and I will now describe these in detail in their prepartihularly to Figs. 11 and 2 of the drawings. 1 I

'r'tccerding to one feature of improvement roli E is mounted to revolve on and swing with a movable revolving tension impellcr P pivotally and preferably movably and adjustably mounted on .thecarrier H to revolve therewith and drag the roll around within the ring. As shown the impeller P has anupwardljy projecting"pin lprevolubly V projecting pin 0 swingingly connecting it to the carrier on which it is yieldingly' sustained by a spring (1 adjustable to vary Its height and resiliently resisting while yieldingly permitting its upward movement and acting to elastically depress it to generate a downward crushing force for the roll when this is desired. The impeller P normall swings on an axis parallel with the axis of the carrier H, but preferably it can'be ad-v justed out of parallel with t is axis to give a slight inclination to the axis of rotation of the roll as it revolves against the inner face of the ring to cause it to tend to run downwardly on this face and thus to elfect a slight friction or attrition. between these faces to supplement its direct crushing action. This is preferably accomplished as shown in Fig 1 by mounting the 'pin 0 in an adjustable or pivoted bushing e by tilting which the pin may be thrown out of parallel with the axis of the carrier H. The roll B is preferably movable vand removable on the impeller P and preferably yieldingly held thereon and subject to varlable resistance or retardation in its movement thereto and in its revolution thereabout. Preferably the roll is bored to reversibly fit on and interlock with the ex which it is axially movable against the tension of a spring j adjustable against a key washer k by a nut Zto vary the tension of the s ring and whendesired to give a brake eflect tending to resist revolution of the roll and increase its drag or attrition on the ring. The bore of the roll is sufficient to clear the washer so that by turning the roll back on the bushing untilv its grooves h coincide with the lugs g the roll can be lifted off for renewal or reversal without disturbing the other parts. 7

According to another feature of improvement my invention provides. an annular partially across the end of each roll B, which preferably form or provide with a reciprocal supplementary and removable endgrind' grinding shelf, ledge, face, or surface. which ing face R. opposite and coacting withthe face Q to grind material between them with a roll and'attrition action dependent on the adjustment of the roll toward the shelf or the weight of the roll or the spring tension app ied to it. The f ces Qand R are more or less fiat to suit the particular \work required of them, but are preferably similarly inclined curved or coned to. vary their proxj imit as theroll moves inwardly and out- {war ly. As shown the face Q is the conical upper surface of a horizontal ring which is seated in thelbottom of the socket for the ring A and held in position thereby, and. the inner edge of which projects inwardly under the rolls and forms the top of the air inlets O, and the plows G clear this edge to throw any fallen material back up on to the 88 and R are not used alone for attrition grindshelf. As shown the crushing face R on the roll instead of being formed integral therewith is formed as a separate conical ring removably coupled to the end of the roll by lugs m reclprocal to and interlocking in sockets in the roll to connect these parts and cause them to rotate and revolve together. The sockets n are duplicated at each end of the rollso that it can be reversed and interlocked with the end grinding ring R in either position, and serve as convenient means for lifting it when removing the roll by raising it off the arm P, the bore of the ring B being suflicient to clear the lugs on the bushing f. I

By this means when the attrition faces Q ing they supplement the grinding action between the rolls B and the ring A by receiving material initially crushed by and falling from them and frictionally further grinding itas it passes between the end offthe roll and the form of a movable annular wall inclined 'similarlyto and movable towards and from' The roll may move axially as its face R rides up the face Q to surmount material on the latter, and in such case exerts an axial attrition efiect on the ring Q in addition to its impactive and centrifugal crushing actions.

According to another feature of improvement I provide a casing S above the crushing chamber which preferablyhas an upwardly and outwardly flaring lower portion 0, acy lindrical portion 12 thereabove and a flat top g and serves as the outer wall for the precipitas tion chamber J, and I preferably provide an adjustable partition T within and sub-dividing the interior of this easing into the precipita'tion chamber J and the selecting chamber K, which partition preferably has the the wall 0 and acts as a bellows or damper to vary the volumetric area of the chambers J and K and the space above its upper edge through which air is permitted to flow from the former to the latter to vary the speed of the air current in these chambers and to correspondingl vary the fineness of the material which s all be floated from the chamber J into the chamber K. When the partition T My invention provides an. adjustable damper U around and under the outlet L preferably as a ring around the depending pipe aflording an outlet L by vertically-ad- ]usting which damper the hel ht of this outlet relatively to the partition can be varied and this damper and the partition are preferably simultaneously oppositely adjusted by three or more tilt evers 1' operated from without by the 'f di lred ends of a rod 8 so as touniformly operate the partsfrom three equidistant suspension points. I The suction pipe of any blower may be connected to the out et L for exhausting the dust and conducting it where desired, and any dust collector may be used there for extracting the dust, and an return pipemay lead from its exhaust to-t e air inlets for return ing and using the air, but according to the preferred form: of my invention I provide the blowerM-above and concentric to the pulverizing chamber and withinthe casin enclosing '1t, which preferably consists '0 blades driven synchrpnously with the carrier H, and preferably at the same being detachably mounted on pipes t carried thereby. The top Q of the inner casings serves as a lower shelf for this blower, and the topwall'u of the outer casing V servesas speed as by thetop wall for the ,way for these blades,,the

outer ends'ofv which are preferably terminating near theirmer inclined ed e of the bev-j eled deflector Y"'or corner oft e casing V to deflect out-blowing air downwardl into the passage N. The casing V mounted on the main frame and encloses the upper part thereof as well as the crushmg, precipitation, selecting, blower, separator, and return chambers, but exposes the lower part thereof for access and ad u'stment.

v, and an inner conical deflecting ring w j parallel with and opposite the wall 0,

which ring deflects the an inwardly and terminates sufliciently a vs the top of the re rably is I referably has avertical cylindrical outer frame C to afford a suitable outward air passage above the latter-through which the returning air may flow. outwardly around the upper edge of the frame C and then downpenings O, to which.

wardly to the return 0 't is guided by the inwardly inclined bottom wall a: of the casing V. .Acoording to another feature of myinvention I preferably provide filtering means W for intercepting and-conductin out of the zone of the current particles floating therein to clean the air before it is returned to the crushing chamber, and I preferably dispose these in the passage N at the point where the air passes outwardly immediately over the top of the frame C. These preferably con sist of a plurality of rows .of hollow 'baflles or troughs extending vertically from the wall a; withtheir inner hollow faces opposed to the outwardly flowing current, those of one row being staggered relatively to those of the next, to form current voids in which floating particles may precipitate while affording spaces between their edges for passage of the returning current. The lower ends of these preferably enter a wall 3/ which is preferably conical and downwardly and inwardly inclined and spaced from the wall w and affords a downward and inward way for the separated dust-as well as an inward wall for the return passage N, Any means for extracting the dust may be used but my invention preferably provides foraminous means surrounding and concentric with the crushing elements and the returning air passage to afford an outward passage for the air cur-e rent and a downward or inward passage for the dust, andfor bringing the separated dust inwardly of the returning air above the latter as returned to the crushing chamber.

According to another feature'of improvement my invention provides separate noncommunicating dust and returning air passages, preferably as alternate ways for the separatedv dust and the return air to conduct the dust below, past, or across the returning air and below its zone and to conduct the air past the dust and above the dust passage and above the dust chamber and into the crushing chamber. vPreferably I provide downwardl o and inwardl and tangentiallydisposed d iist passages intermediate of and simi- 45 larly disposed to the air passages O, which are shown as tubular ways against or through the tangential webs of the frame C which separate-and passages O and connect the upper and lower parts to the frame. Thus the lower 5O ends of the dust ducts X are substantially inwardly of the outer'ends and within a diameter approximately corresponding with that of the main ring A', and the dust can be safely conducted downwardly and inwardly through the returning air zone without mo lestation" and without interfering with exposure of and accessto'the bottom flange of the main frame. i

Accprding to another feature of improvet0 ment the driving mechanism is preferably enclosed within the dust passage and above the dust chamber by non-communicating wall means, and preferably iscarried by the annular bottom frame or casing Y which is re- 55 movably adjusted to the frame C, and aclower ends open into and are enclosed by a dust cone Z removably adjusted to the bottom of the frame Y and terminating at its lower end in the central dust spout F.

The ducts X and 2 preferably are tubular and respectively afford between them spaces or passages affording inward access to the interior, as the air spaces 0 through the frame C, and the openings (1 through the frame Y. The bottom of the frame Y is preferably open and according to one feature of my invention I prefer to removably attach to or suspend from it a hollow or cup shaped frame A afiording a non-communicating wall depending within and spaced from the dust cone Z to utilize the space in the upper part of this while affording around the frame an annular passage for the dust to descend in the cone and at the same time isolate the gear chamber B from the dust. The solid bottom 0 of the base frame 0 affords a closed bottom wall spaced below the crushin chamber and a non-communicating wall above the dust chamber and closes the top of the gear chamber and carries a removable and renewable pan or bottom 6 of wear resisting material which aflords a closed ma terial retaining sustaining bottom wall for the inward current passa e above it and affords around its outer e ge a space for the dust passages X, and affords a bottom for the crushing chamber and protects the top wall 0" of the frame Y, which latter extends inwardly and has a central bearing hub through which the vertical-shaft (5 runs, the lower end of the shaft being adjustably supported on a ball bearing 6'. The earner H is removably keyed "to the shaft d to V revolve with it, and it supports and is driven by a driving hub C keyed to it within the driving chamber.

According to one feature of my invention 'the driving hub is preferably provided with a removable bevel gear D meshing with a bevel pinion E on a shaft f mounted in a bearing 9' between two ducts z and extending outwardly to a pulley H by which the mill may be driven, and is also-preferabl I with a removable pulley flange I by whic it may be driven by a horizontal belt passing through any two of the openings a if direct belt drive is preferred, and is also preferably provided with a removable gear ,G' meshing with a pinion i on' a reducing gear j running in a stationary arm la and meshing with a gear Z on the rotor of a motor H which according to my invention is prefervided with a hollow portion or cylindrical extension m affording an expansion chamber I in communication with and below the crushing chamber and subject to variations of air pressure below the latter, and the top of the chamber is closed by a diaphragm J which preferably utilizes variations in this pressure to vary or regulate speed of feed of material to the chamber, in any suitable manner, but preferably by mounting on it the revolving distributing disc K which receives the feed and projects it radially over the top of the rolls toward the crushing ring.

A central vertical adjustable feed pipe L preferably opens at its lower end opposite the center of the disc K and spaced suflicient- 1y from it to permit the maximum inflow of feed desired. Increase of air pressure below the crushing chamber due to abnormal accumulation of uncrushed material there will cause an upward pressure against the diaphragm and this will deflect it upwardly to raise the feed disc closer to the end of the feed pipe and correspondingly diminish inflow of fresh feed, and the disc will be thus vertically moved automatically to regulate and vary the feed to accord with the speed of withdrawal of fines from the chamber.

The feed pipe is preferably suspended from a hopper M by a pin a adjustable in a spirally stepped notch or slot 0 in the neck of the hopper so that by turning and setting the pipe its vertical position can be adjusted.

My invention preferably also provides for further adjusting and for automatically regulating or varying the speed of feed by an annular ring N surrounding the lower end of the pipe and suspended by rods p adjustably carried by nuts g which I pref-' erably sustain by an annular diaphragm O mounted on the top u and movably surrounding the feed pipe and subject to variations in air pressure adjacent to the intake side of the fan M, so that as the suction is increased due to overloading the crushing chamber the diaphragm 0 will be deflected downwardly and lower the ring N and correspondingly vary the speed of feed with variations in the suction. Preferably I provide an adjustable weighted forked lever P for sustaining-the diaphragm O and regulating its movement.

Thus the feed may be mechanically varied or regulated and may also be automati cally pneumatically varied or regulated by. over pressure below or abnormal suction above the feeding chamber or by either.

My invention preferably provides for mechanically measuring and regulating the supply of feed and for equalizing its discharge to the pulverizer, and this I preferably accomplish by utilizing an axially adjustable spiral screw conveyor Q revolving in a trough R and having an angular outlet discharge edge r over the trough, which edge is preferably adjustable around the conveyor and transversely of its axis to vary its position and angularity to cause the cone of material progressing in front of each conveyor flight to gradually dribble over the edge and thus uniformly discharge itself into the hopper'. The edge is preferably the length of the pitch of the conveyor to extend from the edge of one to the next flight, and may be adjustable by revolving the trough which is preferably pivoted to two independently revoluble bands 8 surrounding the trough and which may be adjusted on it to vary the position and angularity of the edge, the trough being cut with a large enough hole at its under side to permit discharge in any position of the edge. The edge is preferably reversely duplicated at the other side of the flexible angular sheet t on which it is formed, so that it may be used with a right hand conveyor or a left hand conveyor by shifting its position to suit the hand of the conveyor used;

To regulate the amount of material moved by the conveyor its intake end iscpreferably axially adjustable toward the hopper S so that it will take up more of less material according to its adjustment toward the hopper where its end engages the entering material as its angle of flow permits it to run into the trough. The hopper S is preferably inclined and rotatable so that its inlet u may receive an angular or vertical pipe or chute. The outer end of the conveyor shaft is screw threaded to receive a hand wheel 1; for adjusting it, and its inner end plays in the elongatedisocket of the head w of the trough, which is screw threaded and carries a screw it for adjusting this end of the shaft. Speed of revolution of the conveyor is varied by oppositely inclined cone pulleys T one of which is driven by a belt y from the shaft f and drives the other through the adjustable friction belt pulley or ring a.

My invention preferably provides for heating, agitating and disintegrating the infcd material, for which 1 preferably provide one or more annular hollow shelfs or troughs U around the distributing disc K for receiving material thrown from it, which troughs are non-rotatably supported from the casing S and receive revolving stirrers, heaters or agitators V which plow through the material accumulating in the troughs and'agitate and beat it and toss it upwardly and outwardly into the uprising air current at the sides of the troughs so that it can fall bottom or grit pan 6'. The troughs U sus tain lumps of balled material and the stirrers disintegrate these before, throwing them into the air current, to pulverizesuch lumps and adapt theirdust for separation .by the rising current. I

, According to another. feature of my invention the pan b receives all pieces falling through the chamber, and inclined plows or scra ers W push such material outwardly on t e pan and into the path of the lifting plows G .which toss it upwardly across the path of the incoming current through the airinlets 0 so that thiscurrent can catch haund blow inwardly "and upwardly any' fine dust falling into the pan. The plows G have curved upwardly outer flanges to prevent the material being thrown centrifugally. outward,

1 and above them I preferably provide inclined sition and speed of the feeding conveyor, the

- intermittent charges propelled by its flights being equalized in their discharge to the feed 4 ipe by adjustment of the inclined edge a". ormal speed of feed will be determined by adjustment of the feed pipe L toward the distributing disc K, or by adjustment of the regulating ring valve N, and Wlll continue except as varied by the automatic-pressure operated feed varying means J and O or either of them. i

Infed material will be projected across the rising air current which may e'xtractdust from it, the remaining material falling onto the ring A to be crushed against its inner face by the outer faces of the rolls B, after which it will fallonto the shelf Q and be rubbed by the attrition face R of the rolls which push it off the ledge and into the risair current through which the coarse 1 will fall'onto the pan 6' and by which the I dust will be floated up through the crushing.

chamber. The plows G will scrape ofl the 50 particles falling onto the pan and throw them upwardly in front of the rollwhere they will again be subjected to these crushing and rubbing elements and any dust released; by this agitation will be floated up Q by the risingair current, which will carry all dust into the settling chamber J where large particles ma fall back into the crushing chamber whi e fine particles float upwardly.

The bellows partition T will be adjusted to a vertically to vary the area of the current passage in the chamber J to vary the speed of the current therethrough to determine the fineness of dust which it shall float over into the selecting chamber K, where the current will descend around, the lower edge of the plpe L and pass up to the blower. In making this curve itwill throw down larger partides and the size of these will be regulated by varying the outlet damper U.

If an outside blower is used it may be connected directly to the pipe L, and its speed will-correspond to that required for Withdrawing the dust desired and for conveying it to such remote point as desired, at which an ordinary cyclone. dust collector will be located to extractthe dust, and a return pipe will communicate between its relief outlet and the air inlets O, which will be enclosed by a spiral air chamber affording the lower end of such return pipe, as indicated in dotted lines in Figs. .1 and 2, but when these functions are to be effected in one machine the casing V will be adjusted to the base frame C to envelope its upper part and the fan M will be used to withdraw the dust laden air from the pipe L and send it through the passa e N to the air inlets O, and the dust the drivin chamber will be had between the ducts z.

he gear case will be independently suspended from the frame C so that this case can be lowered to ermit renewal of driving parts without dlsmantling the suerstructure. The bottom 0' can then be owered for access to or downward removal of the pan 6', carrier H, rolls B, prshers P, feed (1180 and plows, which can then be replaced from below. i

It will be seen that my invention provides improvements which can be readily and advantageously availed of, and it will be understood that the invention is not limited to the particular details of construction, ar-

rangement, or combination of parts, set forth as constituting its preferred form, since my improvements can be used in whole or in part, and according to any suitable or desired modifications, as the judgment of those skilled in the art may dictate, without departing from the spirit of the invention.

When used in a mill of the ty 0 in which the ring is dis osed about a horizontal axis and is revolve b or revolves around rolls carried by mova le non-rotative members my invention provides for using slightly concave and convex faces on the ring A an rolls B and tapering attrition faces Q} and It at each side of them, and for making the tapering faces on each side of the rolls yieldingly expansively act'axially, by springs j and bolts Z within adjustably determinable limits relatively to the reciprocal faces on the ring and in such use my invention provides for placing my bellows T in the precipitating chamber J 2 above the ring and using my filter W for cleaning the air returning to the casing, the dust passage X extending downwardly between the returning air passages O to con duct the dust below and without the crushing chamber and through and below the zone slight friction or attrition effect between their grinding faces and those of the rin This I preferably accomplish b providing all bearings in parallel and e ectingwind of the shafts by using eccentrioally inclined bearing metal bushings between the shafts and their bearings, and differently faced thrust washers or thimbles in the end of the bearings to compensate for the resulting difference in the angularity between the shafts and the other parts. I o I lVhen a remote dust collector is used my invention provides for more completely extracting the dust from the air coming from the pulverizer and blasted tangentially into the dust collector by providing an upper interior of the dust collector witha cylindrical portion a in which the air may circulate to throw the coarse particles to the eriphery I 'centrifugally, and by providing be ow this a corrugated metal lining 6 in the corrugations of which this dust may descend past and below the zone of the current, and opposite the inner side of each corrugation I provide a hollow vertical trough 0 preferably semi-cincular with its concave face opposed to the direction of revolution of the current so that A. the current may form dead spaces or current Voids in front of these concave faces opposed ripheral crushing.

settle and be conducted through and below 7 the zone of the current, the outer edges of which are in spaced relation to said corrugations to permit the current to divide and pass partly outside and partly inside of each hollow to avoid any tendency to circulate through and around the trough instead of forming air cones directly in front of them, and to equalize this circulation I preferably provide corrugated strips (Z opposite and reversely shaped to the inwardly projecting ribs of the corrugated lining, spaced from this and'from the inner edge of the troughs to afford uniform and similar passages at each side of the troughs and s aced from each other sufficiently to permit air inlet passages for the whirling air inwardly of them, so that as the air current whirls and descends it will be continually shaved off by these strips and directed toward the hollow faces of these troughs, and I provide a guard cone e within the lower ends of these troughs to protect their discharge from molestation by the descending current, and above this an inner cylindrical wall '7 affording around its lower edge an outlet through which current can pass inwardly and upwardly between vanes for checking its whirl, and another wall 9 over which it can descend to pass through a double row of staggered filter troughs or baffles h to reach-the central relief outlet 1? for return of the cleaned air.

For remote conveying of the dust-[the current generated by the fan M alone or supplemental to that of an outside blower is? my invention preferably provides for removing and reversin and changing the current deflecting wall from its normal position around the fan for blowing the current downwardly into the passage N to a reverse position in which one end 1s erpendicular and it is gradually twisted or a j usted in inclination in its extension around the fan so as to give a spiral efi'ect similar to the inner wall of a of the wall Y when thus reversed should not exceed that at which anydust' settling on it will slide down again into the path of the fan,- which will throw it again into the current, and thus prevent clogging of this spiral path for the outblowing current. Insuch case the top of the passage N will be closed with a suitable cover and the relief pipe from the remote dust collector Z will return to and enter this passage tangentially, so that the returning current will pass through the filter W for cleaning it of any dust remaining in it and thence through the air inlets O to the crushing chamber.

When applied to a vertical die mill the revolving fan blades M are mounted eccen-- trically of the casing, as by being mounted on the periphery of a revolving die A so that the inner periphery of the casing C aflords an increasing space similar to the spiral interior of the blower casing to facilitate progress and discharge of the air current which is discharged upwardly at the point of greater area and floats the dust with it into -clined wall u 'to bedeflected thereby side of the crushing chamber near the point where the path of the fan blades is narrowest. In such case the'grit is returned by gravity to the crushing elements. 7

When my improvements are used with an air separator alone as shown in F-i 9 my invention provides a revolving ad ustable horizontal partition m within and for vertically varying the separating chamber and its upper outlet, and carried with a circular outlet varying valve or vertical partition n on the blower M which are simultaneously adjustable to vary the area of the outlet passage above my adjustable bellows T, and it provides a baflle ring 0 around the distributing disc 12 for intercepting and dropping the pulverulent material, and a revolving cylindrical bafile g on this disc, and revolving. inclined flanged plows 1' on this bafiie under and for receiving material dropping from the 1 ring for tossing it upwardly to agitate the rising air current.

In this construction my invention also provides a stationary pan 8 under the feed 'disc and below the air current returning inwardly through the filter W, for receiving fallen it in material, and a plurality of revolving inclined scoops t for tossing this material upwardly in the path of the inward current to permit it to float the fine particlesu ward and throw coarser particles against t e inoutwardly into the tailings screen v in the i tailings cone w. The scoops t and stirrin [pushers w are mounted on spokes sustaine by and revolving with the disc 12*, and act totoss up the material in the path of. the incoming current in an air separator in the same manner as the "lows G act in the construction shown in ig. 1. I

What I claim is: v

1. In a separator, in combination,-means J affording a chamber for receiving pulverulent material, supply means for supplying such material to said chamber, blower means :E0r causing a fluid current to flow up through said chamber for floating fi'ne material from said chamber, means above saidchamber affording an outlet for such current, and ad ustable wall means in said chamber comprising a vertically adjustable transverse wall below and across said outlet and substantially across said chamber and afiording around the outer edge of said wall a s ace through which such current may flow rom said chamber'to said outlet and affording beneath said wall avariable passage for such current andadjustable to vary the area of such vpassage to vary the speed'of flow of such current therethrough to vary the fineness of such material floated thereby.

2. In combination, means 'afiording a chamber for receiving pulverulent material, supply means for supplying such material .tosaid chamber, blower means for causing a fluid current to rise from said chamber to float fine material therefrom, wall means comprising an annular outwardly flaring wall above and aroundisaid chamber and aflordin a separating chamber for receiv ing I sue current, and adjustable means within said separating chamber comprising an adjustable annular conical wall opposite and spaced from said wall and adjustable to vary the space between said walls to vary the "upward passage for such current to vary the fineness of material floated by it throughsuch passage. g Y

3. In combination, means afiording a chamber for receiving pulverulent material to be separated, supply means for supplying material to said chamber, blower means for causing a fluid current 'to flow up through a and around and return beneath said chamber, outer wall means above said chamber affording an upwardly and outwardly flaring separating chamber communicating with said chamber for receivingsuch current, adijustable wall means within said separatin chamber spaced from said flaring wall an affording an upper wall for varying the volumetric area of the passage through said separating chamber to vary the speed of flow of such current therethrough, means abovefsaid adjustable wall afiordm a'current outlet from said separating ciamber,

space through which such current is permitted to flow. V

4. In a separator, in combination, a casing enclosing a chamber, a receptacle within and adjustable valve-means for varying the Sald casing and having upper and lower openings communicating therewith, supply means for supplying pulverulent material i to be separated wlthin said receptacle, blower means for causing a fluid current to flow up through said receptacle and upper opening into said chamber and to return through said lower opening, and adjustable wall means within said receptacle opposite and across and spaced below said upper opening affording a vertically adjustable transverse wall extending substantially across said chamber and affording above said wall a variable space through which such current is permitted to flow to said upper opening and vertically adjustable for varying the space Ehrough which such current is permitted to 5. In a separator, in combination, means affording achamber, supply means for supplying pulverulent material tosaid chamber, receiving shelf means for sustaining such material below said chamber, means affording for supplying pulverulent material thereto,

shelf means for receiving and sustaining such material, means below said chamber and abovesaid receiving means affording an inward current passage communicating with said chamber above said receiving means, blower means for causing a fluid current to flow inwardly above said receiving means and rise in said chamber, revolving lifting up tosser means opposite said receiving means and for lifting such material therefrom into the path of such inward current to subject fine material to its floating action, and deflector means above said revolving means for intercepting coarse material and deflecting it across such current.

-7. In a separator,.in combination, means affording a chamber, supply means for supplying pulverulent material to said chamber, shelf means below said chamber for receiving and sustaining suchmaterial, revolving uptossers above said receiving means and for tossing such material upwardly therefrom, means below said chamber and above said receiving means affording a current passage,

blower means for causing a fluid current to flow through such material to float fine material upwardly into said chamber, deflector means above said revolving means for'intercepting and deflecting outward coarse material raised thereby,and receiver means outwardly of said deflecting means for receivin coarse material deflected therefrom.

8. In a separator, in combination, means affording a separating chamber having a .lower material out-dropping opening and having a lower current inlet and an upward current passage and an upper current outlet, means for supplying material to be separated above said opening for supplying material to be separated in said chamber, means for causing a fluid current to enter said chamber through said lower inlet and flow up through said upward-passage and through said upper outlet for floating fine material from said chamber, a receptacle for separated material below said opening, and shelf means comprising a material retaining sustaining wall below said 'material dropping opening and within said receptacle for sustaining material to be separated between said opening and said receptacle.

10. In a separator, in combination, means affording a separating chamber and having a lower current inlet and an upward current passage and an upper current outlet, means for supplying material to be separated in said chamber, means for causing a fluid current to enter said chamber through said lower inlet and flow up through said upward passage and through said upper outlet for floating fine material from said chamber, a receptacle below said chamber for receiving separated material, and shelf means comprising a material sustaining wall for sustaining material to be separated in the ath of such current and disposed below sa1d chamber and inwardly of said receptacle.

11. In a separator, in combination, means affording a separating chamber and having a lower current inlet and an upward current passage and an upper current outlet, means for supplying material to be separated in said chamber, means'forcausing a fluid current to enter said.chamber through said lower inlet and flow up through said upward passage and through said upper'outlet for float ing fine material from said chamber, a receptacle for receiving separated material below said'lower inlet and shelf means comprising a material sustaining wall for sustaining material to be separated inwardly of said receptacle and below said lower inlet.

12. In a separator, in combination, an outer casing enclosing an outer chamber, an upper receptacle in sa1d casing and enclosinga separating chamber having a lower material dropping opening, and having upperand lower openings communicating with said outer chamber, a lower receptacle for receiv-.

for supplying material to be separated to said upper receptacle, means for causing a fluid current to flow up through said upper receptacle and upper opening into said outer chamber and return through said lower opening for floating fine material from said separating chamber, and shelf means comprising'a material retainingsustaining means spaced below said chamber and below said material dropping opening and between said receptacles for sustaining between said receptacles material to be separated. v

13. In a separator, in combination, means afi'ording a separating chamber having a lower material out-dropping opening, and having a lower current inlet and an up per current outlet communicating with said chamber, means above said opening for supplying materialto be separated to said chamber, means for causing a fluid current to enter said chamber through said inlet and flow up through said chamber and out through said outlet for floating fine material from said chamber, and material tossers below said material dropping opening and in the path of such material dropping through said opening for tossing such material into the path of such current.

14. In a separator, in combination, means affording a separating chamber and having a lower inward current inlet and an upper :urrent outlet communicating with said chamber, means for supplying material to be separated to said chamber, means for causing a fluid current to enter said chamber, horizontally inwardly through said lower inlet and flow upwardly through said chamber and out through said outlet for floating fine material from said chamber, and material tossers opposite saidinlet for tossing such material into the path of such'horizohtally inwardly entering current:

15. In a separator, in combination, means affording a separating chamber having a lower material dropping opening, and having a, lower current inlet and an upper current outlet communicating with said chamber, means above said opening for supplying materi al to be separated to said chamber, means for causing a fluid current to enter said chamher through said inlet and flowup through said chamber and out through said outlet for floating fine material fromsaid chamber, and material uptossers below said material dropping opening'and in the'path of such material dropping through said opening and adjacent said inlet for tossing such material into the path of such current.

16. In a separator, in combination, means aflording a chamber having a lower current inlet and an upper current outlet communieating with said chamber, means for supplying material to be separated to said chamber, means for causing a fluid current to enter said inlet and flow up through said chamber and out through said outlet for floating fine material from said chamber, material deflecting means adjacent to the path of such current for deflecting through such current coarse particles floating in such current, and material tossers opposite said deflecting means for tossing such material into the path of such current and toward said deflecting means.

17 In a separator, in combination, means affording a separating chamber having a lower material dropping opening, and having a lower current inletand an upper current outlet communicating with said chamber, means for supplying material to be separated to said chamber, means for'causing a fluid current, to enter said chamber through saidinlet and flow up through said chamber and out through said outlet to float fine material from said chamber, material retaining sustaining shelf means below said material dropping opening and for sustaining such material in the path of such current, and material dischargers for discharging such material from said sustaining means. 7

18. In a separator, in combination, means aflording a separating chamber material dropping opening and having a lower current inlet and an upper current outlet communicating with said chamber, means above said opening for supplying material to be separated tosaid chamber, means for causing a fluid current to enter said chamber through said inlet and flow up through said chamber lower material dropping opening and having a lower current inlet and an' upper current outlet communicating with said chamber,

means for supplying material to be separated to said chamber, means for-causing a fluid current to enter said chamber through said inlet and flow up through said chamber and out through said outlet for floating fine and out through said outlet for floating fine I material from said chamber, a receptacle for I separated material below said opening, material retaining sustaining shelf means below said material dropping opening and above said receptacle for receiving such ma-' terial dropping through said opening and sustaining such material adjacent to the path of such current, and material uptossing means above said sustaining means for tossing such material from said sustaining means.-

20. In a separator, in combination, a casing enclosing a separating chamber and having a lower current inlet and an upper current outlet communicating with said chamber, means for supplying material to be separated to said chamber, means for causing a 'fluid current to enter said chamber through said inlet and flow up through said chamber and out through said outlet for floating fine material from said chamber, a receptacle for separated material below said supplying means, material sustaining shelf means below said supplying means and inwardly of said receptacle for sustaining such material adj aoent to the path of such current, and material tosser means inward of said receptacle for tossing such material from said sustaining means into the path of such current,

21. In a separator, in combination, a casing enclosing a separating chamber and having a lower current inlet and an upper current outlet communicating with said chamber. means for supplying material to be separated to said chamber, means aflording a return current passage communicating between said outlet and said inlet and affording an endless passage through and around said chamber, means for causing a fluid current to enter said chamber through said inlet and flow up through said chamber and through said outlet and return through said current passage for floating fine material from said chamber,

material sustaining shelf means below and affording a lower wall for said lower inlet and below said supplying means and affording a lower wall for said chamber and for recelving and sustaining such material in the path of such returning current, and tosser means above said wall and around said inlet for tossing such material into the path of such'returningcurrent.- p

22. In a separator, in combination, a cas- 4 ing enclosing a separating chamber and having a lower current inlet and an upper current outlet, supply means for supplyinomaterial to be separated to said chamber, b ower means for causing a fluid current to enter said chamber through said inlet and flow up through saidchamber and through said outlet to float fine material from said chamber, and means within said chamber comprising a transverse cross chamber wall extending a substantial distance across said chamber and spaced below and adjacent to said outlet and spaced a substantial distance above said supplying means andafi'ording below said wall and above said supplying means a substantial selection chamber in which large particles floating in such current toward said outlet may precipitate, and affording around the edge of said wall a passage for such current through which such current may. flow from said'selection chamber to said outlet.

terial to be separated to said chamber, blower means for causing a fluid current to enter.

said chamber through said inlet and flow up through said chamber and through said outlet to float fine materialfrom sald chamber, valve means above said chamber for varying thespace through which such current is permitted to flow from said chamber, and wall means below said valve means and within said chamber comprising a transverse cross chamber wall extending a substantial distance across said chamber and spaced below and adj acentto said outlet and spaced a substantial distance above said supplying. means and all'ording below saidwall and above said supplying means -a substantial selection chamber in which large particles floating in such current toward said outlet may precipitate and affording around the edge of said wall a passage for sucli' current through which such current may flow from said selection chamber to said outlet, said valve means adjustable for varying the outflow of such current from said selection chamber for varying the fineness of material separated therein. I

24. In a separator, in combination, a casing enclosing a separatin chamber and havcomprising a transverse cross chamber wallextending a substantial distance across said chamber and spaced below and adjacent to said outlet and spaced a substantial distance above said supplying means and affording below said wall and, above said supplying means a substantial selection chamber in which large particles floating in such current toward said outlet may precipitate and aflording around the edge of said wall a passage for such current through which such current .may flow from said selection chamber to said outlet.

25. In a separator, in combination, a casing enclosing a separating chamber and having a lower current inlet and an uppercurrent outlet, supply means for supplying material to be separated in said chamber, blower v and means within said chamber comprising a transverse cross chamber partition wall extending .a substantial distance across said chamber and spaced below and adjacent to said outlet and spaced a substantial distance above said supplying means and affording be low said wall and above said supplying means a substantial selection chamber in which large particles floating in such current toward said outlet may precipitate and affording around the edge of said wall a pas sage for such current through which such current may flow from said chamber to said outlet, said wall and said supply means the one vertically adjustable relatively to the other for varying the vertical distance between said wall and said supplying means for varying the fineness of material separated in said substantial ch amber.

26. In a separator, in combination, a casing enclosing a separating chamber and having a lower current inlet and an upper current outlet, supply means for supplying material to be separated in said chamber, blower means for causing a fluid current to enter said chamber through said inletand flow up through said chamber and through said outlet to float fine material from said chamber,

selection chamber in which large particles.

floating in such current toward said outlet may precipitate and affording below said valve means and above said wall a passage for such current through which such current may flow from said selection chamber to said outlet.

27 In a separartor, in combinatioma casing enclosing a separating chamber and having a lower current inlet and an up er current outlet, supply means for supplymg ma terial to be seperated in said chamber, blower means for causing a fluid current to enter said chamber through said inlet and flow up through-said chamber and through said outlet to float fine material from said chamber, rotary valve means for varying the space through which such current is permitted to flow, and wall means below'said valve means and within said chamber comprising a transverse cross chamber wall extending a substantial distance across said chamber and spaced below and adjacent to said outlet and spaced a substantial distance above said supplying means and affording below said wall and above said-supplying means a substan-. tial selection chamber in which large par-- ticles floating. in such current toward said outlet may precipitate and affording below said valve means and above said wall a passage for such current through which such current may flow from said selection chamber .to said outlet.

28. Ina separator, in combination, a casing enclosing a separating chamberand having a lower current inlet and an upper current outlet, supply means for supplying material to be separated in said chamber, blower means for causing a fluid current to enter said chamber through said inlet and flow up through said chamber and through said outletto float fine material from said chamber, valve means for varying the space through which such current is permitted to flow, and rotary wall means below said valve means and within said chamber comprising a rotary transverse cross chamber wall extending a substantial distance across said chamber and spaced below and adjacent to said outlet and spaced a substantial distance above said supplying means and afl'ording below said wall and above said supplying means a substantial selection chamber in which large particles floating in such current toward said outlet may precipitate and affording below said valve means and above said walla passage for such current through which such current may flow from said selection chamber to said outlet. 7

' 29. In a separator, in combination, 9, casing enclosing a separating chamber and having a lower current inlet and an upper cur-v rent outlet, supply means for supplying material to be separated in said chamber, blower means for causing a fluid current to enter said chamber through said inlet and flow up through said chamber and through said outletto float fine material from said chamber,

and adjustable wall meanswithin said chamber comprising, an adjustable transverse cross chamber wall extending a substantial distance across said chamber and spaced below and adjacent to said outlet and spaced a substantial distance above said supplyin means and affording below said wall and above said supplying means a substantial selection chamber in which large particles floating in such current toward sald outlet may precipitate and aflording around the edge of said wall a passage for such current through which such current may flow from said selection chamber to said outlet.

30. In a separator, in combination, a casing enclosing a separating chamber and having a lower current inlet and an upper cur rent outlet, supply means for supplying material to be separated in said chamber, blower means for causing a fluid current to enter said chamber through said inlet and flow up through said chamber and through said outlet to float fine material from said chamber, valve means for varying the space through which such current is permitted to flow, and adjustable wall means below said valve means and within said chamber comprising an adjustable transverse cross chamber wall exsaid wall a passage for such current'through which such current may flow from said se lection chamber to said outlet.

31. In a separator, in combination, a casing enclosing a separating chamber and having a lower current inlet and an upper current outlet, supply means for supplying material to be separated to said chamber, blower means for causing a fluid current to enter said chamber throu h said inlet and flow u through said cham er and through said out et to float fine material from said chamber, valve means for varying the space through which such current is permitted to flow, and vertically adjustable wall means below said valve means and within said chamber comprising a vertically adjustable transverse cross chamber wall extending a substantial distance across said chamber and spaced below and adjacent to said outlet and spaced a substantial distance above said supplying means and affording below said wall and above said supplyin means a substantial adjustable selection c amber in which large particles floating in such current toward said outlet may precipitate, and afl'ordin g below said valve means and above said wall a passage for such current from said selection chamber to said outlet and verticall adjustable to vary the space through whic such .current is permitted to flow, for varying the fineness of material se arated in said substantial chamber.

32. n aseparator, in combination, means affording a separating chamber having a lower material dropping opening and having a lower current inletand an upwardcurrent passage and an upper current outlet,'supply means above said opening for supplying material to be separated in said chamber, blower means for causing a fluid current to enter said chamber through said inlet and flow up through said upward passage and through said upper outlet for floating fine material from said chamber, means communicating between said outlet and said inlet affording a return passage for such current, filter means in said return passage for cleaning from such returning current fine material floating in such current, and shelf means comprising a material retaining sustaining wall below said dropping opening for receiving material to be separated dropping through such opening and sustaining such material adjacent the path of such cleaned returning current entering through said'inle't. I

33. In a separator, in combination, means afiording a separating chamber having a lower material dropping opening and having a lower current inlet and an upward current passage and an upper current outlet, supply means above said opening for supplying material to be separated in said chamber, blower means for causing a fluid current to enter said chamber through said inlet and flow up through said upward passage and through said upper outlet for floating fine material from said chamber, means communicating between said outlet and said inlet affording a return passage for such current, filter means means above said opening for supplyin material to be separated in said chamber, b ower means for causing a fluid current to enter said chamber through said inlet and flow up through said upward passage and through said upper outlet for floating fine material from said chamber, means communicating between said outlet and said inlet affording a return passage for such current filter means across said return passa e for cleaning from such returning current ne material floating in such current, and shelf means affording a material retaining sustaining wall below said dropping opening and below said inlet for receiving material to be separated dropping through said opening and sustaining such materlal in the ath of such cleaned current returning to said inlet.

35. In a separator, in combination, means aflording a separating chamber having a lower material dropping opening and having a lower current inlet and an upward current passage and an upper current outlet, supply means above said opening for supplying material to be separated in said chamber, blower means forcausing a fluid current to enter said chamber through said inlet and flow up through said upward assage and through .said upper outlet for oating fine material from said chamber, means communicating between said outlet and said inlet affording a return passage for such current, filter means around said return passage for cleaning from such returning current fine material floating in such current, and shelf means afiording a material retaining sustaining wall below said dropping opening and spaced below said lower material dropping op'eningand-havmg.

chamber forreceiving material to be separated dropping through said opening and sustaining such material below-said chamber and adjacent the path of such turnin' current. .36; n a separator, in combination, means a-flording a" separating chamber havinga cleaned rea lower current inlet and an upward current passage and an upper current outlet, supply means above said'opening for supplying material to be separated insaid chamber, blower means for causing a fluidicurrent to enter said chamber through said inlet and flow. up through said upwardpassage and through said upper outlet for floating fine material from said chamber, means communicatmg between said outlet and said'inlet affording a return passage for such current, filter means across said return passage for cleaning from such returning current fine material floating in. such current; and shelf means aflording a material retaining sustaining wall below 'taid-dropping opening and below said return current passage for receiving material to be separated dr pping through said opening and v sustaining each material below the path of such cleaned returning current.

v37. In a separator. in combination, means afi'ording a separating chamber having a lower material dropping opening and having a lower current inlet and an upward current passage and an upper current outlet. supply means above said opening for supplying material to be separated in said chamber. blower means for causing a fluid current to enter said chamber through said inlet and flow up through said upward passage and through said upper outlet for floating fine material from saidchamber, means communicating betweensaid outlet and said inlet affording a return passage for such current, filter means in said return passage for cleaning from such returning current fine material floating 1n such current, and shelf means afiording a material retaining sustaining wall below said supplying means for receiving material to be separated falling from such supplying means and sustaining such material adj acent' the path of such cleaned returning current and spaced at its outer edge from the wall of said chamber and affording around its outer edge and between it and such wall an annular passage forsuch cleaned current returning from said cleaning means to said chamber.

38. In a. separator, in combination, means affording a separating chamber having a material dropping-opening and having a lower current inlet and an upward current passage and an upper current outlet, supply means for supplying material to be separated in said chamber, blower means for causing. a

-fluid current to enter said chamber through said inlet and flow up through said upward passage and through said outlet for floating fine material from said chamber, means surrounding said chamber afi'ordmg a return.

passage 1 for such current communicating om said outlet to said inlet, filter means around said chamber and in said return passage for cleaning-from such current fine mater1al floatm in such current returning toward said 1n et, and shelf means alfording a material retaining sustaining wall below said dropping opening and inwardly of and sur-' rounded by said cleaning means for receivin material to be separated dropping throng szti-d openin and'sustaining such material in the path- 0 such cleaned returning current cleaning from such current fine material floating in such current to said inlet, and shelf means afi'ordmg a material retaining su'stamso i ing wall below said opening and below said inlet, for receiving materialto be separated dropping through said opening, and sustaini'ng'such material below said inlet and ad jacent the path of such cleaned currentreturning from said cleaning means.

40. In a separator, in combination, a casing enclosing a separating chamber having a material dropping opening and having a lower current inlet and an upper current outlet, supplymeans for supplyingmaterial to be separated in said chamber, blower means for causing a fluid current to enter said chamber through said inlet and flow up through said outlet for floating fine material from said chamber, means affording a return current passage communicating between saidoutlet and said inlet for returning such current, filter means in said passage for cleaning fromsuch current fine material floating in such current to said inlet, and material uptossermeans below said dropping opening and in the path of material to be separated dropping through such openingfor uptossing such material in the path of such cleaned current returning from said cleaning means.

- 41. In a separator, in combination, means aflording a separating chamber having a material dropping opening and having a lower current inlet and an upper current outlet,

supplyvmeans for supplying material to be se arated in said chamber, blower means for causing a fluid current to enter said chamber through said inlet and flow up through said outlet for floating fine material from said chamber, means affording a return current passage communicating between said outlet and said inlet for returning such current to. said inlet, filter means in said return passage for cleaning from such current fine material floating in such current to said'inlet, and material tosser means below said opening and below said cleaning means and in the path of material to be separated dropping through said opening for tossing such material into the path of such cleaned current returning through said cleansing means.

42. In a separator, in combination, means affording a separating chamber and having a lower current inlet and an upper current outlet, supply means for supplying material to be separated in said chamber, blower means for causing a fluid current to enter said chamber through said inlet'and flow up through said outlet for floating fine material from said chamber, means affording a return current passage communicating between said outlet and said inlet for returning such current to said inlet, filter means in said passage and around said inlet for cleaning from such current fine material floating in such current to said inlet, and material tosser means below said dropping opening and concentric of said cleaning means for receiving material to be separated dro ping through said opening and tossing suc ma terial concentrically of said cleanin means into the path of such cleaned returning current.

In witness whereof, I have hereunto signed my name.

GEORGE HOLT FRASER.

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