US1936593A

US1936593A - Pulverizer and separator

Info

Publication number: US1936593A
Application number: US560588A
Authority: US
Inventors: Fraser George Holt
Original assignee: Individual
Current assignee: Individual
Priority date: 1925-04-27
Filing date: 1931-09-01
Publication date: 1933-11-28
Anticipated expiration: 1950-11-28

Description

NOV. 28, 1933. H, FRASER 1,936,593

PULVERIZER AND SEPARATOR Original Filed April 27, 1925 3 Sheets-Sheet l ig- F f i 1 IN V EN TOR.

NOV. 28, 1933. G H. FRASER 1,936,593

PULVERIZER AND SEPARATOR Original Filed April 27. 1925 3 Sheets-Sheet 2 All IN V EN TOR.

Nov. 28, 1933. FRASER 1,936,593

PULVERIZER AND SEPARATOR Original Filed April 27. 1925 s Sheis-Sheet s IN V EN TOR.

Patented Nov. 28 1933 UNITED STATES PATENT 4 OFFICE Original application April 27, 1925, Serial No.

26,033. Divided and this application September 1, 1931. Serial No. 560,588

20 Claims.

This application is a division of my original application Serial No. 26,033 filed April 27, 1925, patented Dec. 1, 1931, No. 1,834,095, of which the following is a specification.

This invention relates to crushers or pulverizers for grinding rock or other materials, and to air separators or dust collectors for separating and collecting fine material, and aims to provide improvements in pulverizers and pulverizing and separating machines for use with mills of the ring and roll or other type, and in air separators used in connection therewith or otherwise.

My said invention comprises improvements in air separators which are claimed in my said original application, and improvements in pulverizers and pulverizing and separating machines which are claimed in this divisional application.

Heretofore a plurality of planetary rolls have been revolved about the interior of a crushing die to pulverize material between the peripheral crushing faces of the rolls and the inner crushing face of the die. Centrifugal force incident to the speed of the planetary 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 fioat out the fine material to 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 uncrushed material up 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 withdraw and convey the fine material to its destination. 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 crushing zone of the mill to return the air with a whirling effect below and inwardly of the ring.

Heretofore, in return current pulverizing and separating machines in which the dust chamber is below the crushing chamber, and both are enclosed in an outer casing, such as shown in my Patent #1,499,516 dated July 1, 1924, such casing has enclosed the dust chamber below the crushing chamber, but as a part of the endless current passage through which the separating current is flowed under and up through an openv bottom wall of the crushing chamber, through fine material interceptor means below such wall and above the blower means for circulating such current, an arrangement requiring undesirable headroom and hazarding molestation by the returning current to the fine material in the dust chamber, and not insuring prevention of communication between the dropped coarse material and the fine dust.

My invention aims to provide improvements especially applicable to return current mills operating on either of these principles, and to provide an improved combined pulverizing and airseparating machine in which the fine chamber may be below the path of the returning separating current and protected from communication with coarse material dropping from the crushing chamber, and in which the fineness of dust may be easily varied.

To this end in carrying out the preferred form of my invention I preferably provide an outer casing enclosing a settling chamber, an inner casing enclosing a crushing chamber within and in spaced relation to said outer casing and having an upper fine material outlet and a lower uncrushed material dropping opening communicating with said settling chamber and affording an endless currentpassage, up through, out over, down around and returning in under, said crush ing chamber, crushing elements in said crushing chamber intermediate said outlet and said opening, a fine receiver around and below said opening and in communication with said settling chamber, and a communication prevention closed bottom wall spaced below said dropping opening and aifording a bottom wall for said current passage and an inward current inlet communicating from said settling chamber to said lower opening and afiording around said bottom wall a passage for fine material from said settling chamber to said fine chamber, whereby the separating current may circulate up through and 9 around and return in under the separating chamber without traversing the fine chamber, and I preferably provide'fine material interceptor means around or above said bottom wall and across the path of such current for cleaning from such current fine material floating in such current returning to said lower opening; and I preferably provide revolving fan blades above and concentric of such dropping opening and such filter for causing such current to flow up through and out over said separating chamber and return through such cleaning means to said lower opening, and I preferably provide a vertically variable partition wall "within said chamber and below and adjacent and extended outwardly across said 110 outlet and a substantial distance across said chamber and affording above it a vertically variable space through which current may flow from said chamber to said outlet for varying such current, and affording below it a variable separating chamber in which coarse particles may precipitate, and the area of which may be varied to vary the fineness of dust flowing to said outlet, and I preferably provide cleaning means encircled coarse material uptossers below said dropping opening and above said bottom wall for uptossing to said pulverizing elements and inwardly of said cleaning means and adjacent the cleaned returning current coarse material retained by said wall, 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. l is a side elevation, partly in vertical axial section, of the preferred form of my improved pulverizer and separator;

Fig. 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 3--3 in Fig. 1;

Fig. 4 is a small side elevation thereof as arranged for elevating or conveying the dust laden air to a remote point for separation by an outside dust collector, the parts being broken out to show them partly in section on the planes of the lines 4-4 in Fig. 5;

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

Fig. 6 is an enlarged axial section of the roll.

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 pulverizingseparating machine.

These parts may be of any usual or suitable construction affording a crushing chamber and crushing elements therein which can co-operate to pulverize coarse infed material 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 co-acting crushing faces of these elements.

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 in a horizontal plane about this axis and each has a vertical cylindrical peripheral crushing face running against and co-acting with the crushing face of the ring to crush material between these faces. A plurality of planetary rolls is preferably used, four being shown, and each being movable radially of the ring and' free to rotate 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 "1 advance of the biglit of the rolls. A revolving head or carrier H sustains and propels the rolls and plows around in a crushing chamber I. The crushed material passes from the crushing chamber into a settling chamber or precipitation chamber J from which pieces are returned to the crushing chamber and finer pieces inlets or ducts O at the side of this chamber re-- mote from the chamber J, this endless circuit comprising all said chambers and the blower chamber and the dust collector or separator and such communicatingor external passages as are desirable or necessary to connect and include these 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 preferred form, referring particularly to Figs. 1 and 2 of the drawings.

According to one feature of improvement each roll B is mounted to revolve on' and swing with a movable revolving tension impeller P pivotally and preferably movably and adjustably mounted on the carrier H to revolve therewith and drag the roll around within the ring. As shown the impeller P has an upwardly projecting pin a revolubly carrying the roll,- a horizontally extending body beneath the roll and a downwardly projecting pin 0 swingingly connecting it to the carrier on which it is yieldingly sustained by a spring 41 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 normally swings on an axis parallel with the axis of the carrier H, but preferably it can be adjusted out of parallel with this 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 effect a slight friction or attrition between these faces to supplement is 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 and removable on the impeller P and preferably yieldingly held thereon and subject to variable resistance or retardation in its movement thereto and in its revolution thereabout. Preferably the roll is bored to removably fit on and interlock with the exterior of a bushing 1 having lugs g which pass through grooves h in the roll and enter recesses z therein to lock the two together, and the bushing 1 runs on the pin a upon which it is axially movable against the tension of a spring 9' adjustable against a keyed washer is by a nut Z to vary the tension of the spring and when desired to give a brake effect tending to resist revolution of the roll and increase its drag or attrition on the ring. The bore of the roll is sufilcient to clear the washer so that by turning the roll back on the bushing until its grooves h coincide with the lugs g the roll can be lifted off for renewal or reversal withoutdisturbing the other parts.

According to another feature of improvement my invention provides an annular grinding shelf,

ledge, face, or surface, which is preferably a separate ring of relatively non-wearing material Q, auxiliary to and at the lower side of the grinding ring A and projecting inwardly therefrom opposite and partially across the end of -each roll B, which I preferably form or provide with a reciprocal supplementary and removable end grinding face R opposite and co-acting with the 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 applied to it. The faces Q and R are more or less flat to suit the particular work required of them, but are preferably similarly inclined curved or coned to vary their proximity as the roll moves inwardly and outwardly. As shown the face Q is the conical upper surface of a horizontal ring which is seated in the bottom 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 shelf. 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 rollby lugs m reciprocal 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 roll so 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 sufficient to clear the lugs on the bushing 7.

By this means when the attrition faces Q and R are not used alone for attrition grinding 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 it as it passes between the end of the roll and the face Q from which it may fall into the incoming air current for floating out the fines and on to the' plows or elevating the coarse for further grinding.

The face Q may be formed integrally with the ring A and the face R may be integral with its roll B, but to provide fordifference in wear effect, and for ,yarying the several crushing faces to suit different materials or requirements I prefer to segregate these faces by forming them'on separable and independently removable members.

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 effect 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 preferably has an upwardly and outwar ly flaring lower portion 0, a cylindrical portion p thereabove and a flat top q and serves as the outer wall for the precipitation chamber J, and I preferably provide an adjustable partition T within and sub-dividing the interior of this easing into the precipitation chamber J and the selecting chamber K, which partition preferably has the form of a movable annular wall inclined similarly to and movable towards and from 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 correspondingly vary the fineness of the material which shall be floated from the chamber J into the chamber K. When the partition T is adjusted toward the wall 0 current speed is increased and larger particles will be carried over the upper edge of the partition and into the chamber K, from which those fine enough to float out the outlet will pass and those too coarse will fall and return to the crushing chamber around the lower edge of the partition.

My invention provides an adjustable damper U as a ring around the depending pipe affording an outlet L, by vertically adjusting which damper the height of this outlet relatively to the partition T can be varied and this damper and the bellows are preferably simultaneously oppositely adjusted by three or more tilting levers r operated from without by the forked ends of a rod s so as to uniformly operate the parts from three equidistant suspension points.

The suction pipe of any blower may-be connected to the outlet L for exhausting the dust and conducting it where desired,- and any dust collector may be used there for extracting the dust, and any return pipe may lead from its exhaust to the air inlets for returning and using the air, but according to the preferred form of my invention I provide the blower M above and concentric to the pulverizing chamber and within the casing enclosing it, which preferably consists of blades driven synchronously with the carrier H, and preferably at the same speed as by being detachably mounted on pipes t carried thereby. The top q of the inner casing S serves as a lower shelf for this blower, and the top wall u of the outer casing V serves as the top wall for the way for these blades, the outerends of which are preferably terminated near the inner inclined edge of the beveled deflector Y or corner of the casing V to deflect out-blowing air downwardly into the passage N. The casing V is mounted on the main frame C and encloses the upper part thereof as well as the crushing, precipitation, selecting, blower, separator and return chambers, but exposes the lower part thereof for access and adjustment. It preferably has a'vertical cylindrical outer wall 0, and an inner conical deflecting ring to parallel with and opposite the wall 0, which ring deflects the air inwardly and terminates sufilciently above the top of the 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 downwardly to the return openings 0, to which it is guided by the inwardly inclined bottom wall IL, of the casing V.

According to another feature of my invention I provide filtering means W for intercepting and conducting 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 consist of a plurality of rows of hollow baffles or troughs extending vertically from the wall to with their 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 11 which is preferably conical and downwardly and inwardly inclined and spaced from the wall at 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 current and a downward or inward pas:age for the dust, and for 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 alternate ways for the separated dust and the return air to conduct the dust across the'returning air and below its zone and to conduct the air past the dust and into the crushing chamber. Preferably I provide downwardly and inwardly and tangentially disposed dust passages X intermediate of and similarly disposed to the air passages O, which are shown as tubular ways against or through the tangential webs of the frame C which separate the passages O and connect the upper and lower parts to the frame. Thus the lower 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 molestation and without interferring with exposure of and access to the bottom flange of the main frame.

According to another feature of improvement the driving mechanism is carried by the annular bottom frame or casing Y which is removably adjusted to the frame C, and according to my invention is provided with a plurality of downwardly and inwardly extending dust ducts z disposed radially under and respectively an extension of the corresponding duct X in the frame C to conduct the dust below and past the driving mechanism and inwardly toward the axial center of the machine, which fducts at their lower 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 z 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 a 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 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 closes the top of the gear chamber and carries a removable and renewable pan or bottom 22, of wear resisting material which 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 d runs, the lower end of the shaft being adjustably supported on a ball bearing 6. The carrier H is removably keyed to the shaft d to 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 provided with a removable bevel gear D meshing with a bevel pinion E on a shaft I mounted in a bearing g between two ducts z and extending outwardly to a pulley h by which the mill may be driven, and is also provided with a removablepulley flange F by which 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 provided with a removable gear G meshing with a pinion i on a reducing gear 7" running in a stationary arm is and meshing with a gear I on the rotor of a motor H which according to my invention is mounted in the hollow frame A to afford a direct motor drive with suitable speed reducing and compensating couplings, and switches and electrical connections, all of which may be removably mounted in the hollow lower frame and suitably connected through the openings a of the gear frame. In this manner the device may be driven in whichever of several ways is best suited to local conditions.

According to another feature of improvement the carrier H is preferably provided 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 suiliciently 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 n 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 also provides for further ad-,

justing and flu. 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 q which I preferably sustain by an annular diaphragm O mounted on the top it 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 loU According to another feature of my invention the pan 1) receives all pieces falling through the chamber, and inclined plows or scrapers W push such material outwardly on the pan and into the path of the lifting plows G which toss it upwardly across the pathof the incoming current entering through the air inlets 0 so that this current can catch and 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, and above them I preferably provide inclined deflectors X against which upwardly projected large particles may impinge and be deflected outwardly across and out of the zone of the rising current, and may fall onto the annular grinding faces.

In operation, speed of supply of material to be pulverized 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 will continue except as varied by the automatic pressure operated feed varying means J and O or either of them.

Infed material will be projected across the rising air current which may extract dust 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 fall onto the shelf Q and be rubbed by the attrition face R of the rolls which push it off the ledge and into the rising air current through which the coarse will fall onto the pan b and by which the dust will be floated up through the crushing chamber. The plows G will scrape off the particles falling onto the pan and throw them upwardly in front of the roll where they will again be subjected to these crushing and rubbing elements and any dust released by this agitation will be floated up by the rising air current, which will carry all dust into the settling chamber J where large particles may fall back into the crushing chamber while fine particles float upwardly.

The bellows partition T will be adjusted 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 pipe L and pass up to the blower. In making this curve it will throw down larger particles and the size of these will be regulated by varying the outlet damper U.

If an outside blower k2 is used it may be connected to the casing V above 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 Z will be located to extract the dust, and a return pipe i2 will communicate between its relief outlet and the air inlets O, which will be enclosed by the casing V affording the lower end of such return pipe, as indicated in'Figs. 4 and 5, 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 passage N to the air inlets O, and the dust passages X will be used to conduct the dust through the return air, which will be cleaned by separating the dust from it as it returns, and be conducted past the drive gears to the dust chamber and discharge below and central of the machine.

Access to the dust chamber may be had by releasing and lifting the lower inclined wall a: of the casing V, which wall is preferably detachable and telescopically engages the cylindrical wall '1) to permit this. Access to the driving chamber will be had between the ducts z. The gear case will be independently suspended from the frame C so that this case can be lowered to permit renewal of driving parts without dismantling the superstructure. The bottom 0' can then be lowered for access to or downward removal of the pan b, carrier H, rolls B; pushers P, feed disc and plows, which can then be replaced from below.

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, arrangement, 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.

For remote conveying of the dust the current generated by the fan M alone or supplemental to that of an outside blower k2 my invention preferably provides for removing and reversing and changing the current deflecting wall Y from its normal position around the fan for blowingthe current downwardly into the passage N to a reverse position in which one end is perpendicw lar and it is gradually adjusted in inclination in its extension around the fan so as to give a spiral effect similar to the inner wall of a blower affording a space around the fan gradually increasing to the other end and there discharging into a pipe leading to the suction of an auxiliary blower k2 if used or direct to a remote dust collector Z at a point where the dust is to be discharged. The inclination of the wall Y whenthus reversed should not exceed that at which 120 any dust 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. In such case the top of the passage N will be closed by the reversal of the well Y, 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.

What I claim is:

1. In a pulverizer, an outer casing enclosing a settling chamber, an inner casing enclosing a crushing chamber within and in spaced relation to said outer casing and having a lower current inlet and an upward current passage and an upper outlet for fine material and a lower coarse material dropping opening in communication with said settling chamber, said casings having spaced walls between said inlet and said outlet affording an endless current passage up through, out over, down around, and in under, said crushing chamber, crushing elements in said crushing chamber between said outlet and said opening, for crushing material in said crushing chamber, operator means in operative relation to said elements for operating said elements, supply means in communication with said elements, for supplying material to be crushed to said elements, 150

blower means in communication with said endless passage, for causing a fluid current to flow up through and out over said crushing chamber, down through said settling chamber, and to return in under said crushing chamber, to fioat fine material into said settling chamber, a fine material receiver spaced around and below said dropping opening and in communication with said settling chamber for receiving fine material from the latter, and a coarse material retainer closed bottom wall for said crushing chamber, below said current passage and inwardly of said fine receiver, and spaced below and opposite said dropping opening affording a closed bottom wall for said current passage inwardly of said fine receiver, for receiving from such elements such dropped coarse material below said opening, and for retaining such material below the path of such current and inwardly of said fine receiver.

2. In a pulverizer, an outer casing enclosing a settling chamber, an annular crushing die disposed in an approximately horizontal plane with in and in spaced relation to said casing and having an inner crushing face affording a crushing chamber having an upward current passage and an upper opening for discharging fine material and a lower opening for dropping coarse material, said openings in communication with said settling chamber and said casing and said die having spaced walls between said openings affording an endless current passage up through, out over, down around, and returning in under, said die, a rotatable crushing roll having a peripheral crushing face within and co-operating with said die to crush material between said faces, rotary means in operative relation to said roll, for rotating said roll, supply 'means in communication with said roll, for supplying material to be crushed by said roll, blower means in communication with said endless passage, for causing a fluid current to circulate up through, out over, down around, and to return in under said die, to float fine material into said settling chamber, a fine material receiver spaced around and below said dropping opening and in communication with said settling chamber for receiving such fine material from the latter, and a coarse material retainer closed bottom' wall for said crushing chamber, below said current passage, and spaced below said die and opposite said dropping opening, and inwardly of said fine receiver, and affording a closed bottom wall for said current passage, and afiording around said wall communication between said settling chamber and said fine receiver, for receiving such coarse ma terial from said die, and for retaining such coarse material above said fine receiver.

3. In a pulverizer, an outer casing enclosing a settling chamber, an inner casing enclosing a crushing chamber within and in spaced relation to said outer casing and having an upper outlet for fine material and a lower coarse material dropping opening and an upward current passage between said opening and said outlet in communication with said settling chamber, said casings having spaced walls affording an endless current passage up through, out over, down around, and in under, said crushing chamber, crushing elements in said crushing chamber between said outlet and said opening, for crushing material in said crushing chamber, operator means in operative relation to said elements, for

operating said elements, supply means in com-- munication with said elements, for supplying material to be crushed to said elements. blower means .in said endless passage, for causing a. fluid current to fiow up through and out over said crushing chamber, down through said settling chamber, and to return in under said crushing chamber, to float fine material into said settling chamber, a fine material receiver spaced around and below said dropping opening and in communication with said settling chamber for receiving fine material from the latter, and a communication prevention material retainer closed bottom wall for said crushing chamber, below said endless passage, and above and inwardly of said fine receiver and spaced below said dropping opening, and affording above said fine receiver and below said crushing chamber a closed bottom wall for said endless passage, and a closed top Wall for said fine receiver, and affording around said wall communication from said settling chamber to said fine receiver, for retaining coarse material dropping from said elements through said dropping opening, and for preventing communication between said dropping opening and said fine receiver.

4. In a pulverizer, an outer casing enclosing a settling chamber, an annular crushing die disposed in an approximately horizontal plane within and is spaced relation to said casing and having an inner crushing face affording a crushing chamber having an upward current passage, and an upper opening for discharging fine material and a lower opening for dropping coarse material, said openings in communication with said settling chamber and, said casing and die having spaced walls between said openings affording an endless current passage up through, out over, down around, and returning in under, said die, a rotatable crushing roll having a peripheral crushing face within and co-operating with said die to crush material between said faces, rotary means in operative relation to said roll, for rotating said roll, supply means in communication with said roll, for supplying material to be crushed by said roll, blower means in said endless passage for causing a fluid current to circulate up through, out over, down around, and to return in under said die, to fioat fine material into said settling chamber, a fine material receptacle spaced around and below said dropping opening and in communication with said settling chamber, for receiving such fine material from the latter, and a communication prevention closed bottom wall for said endless passage below said crushing chamber, intermediate said die and said fine receiver and spaced below said die, affording around and above said closed wall communication between said crushing chamber and said settling chamber, and affording around said wall communication from said settling chamber to said fine receiver, for preventing communication between such crushing chamber and said fine receiver.

5. In a pulverizer, an outer casing enclosing a settling chamber, an inner casing within and in spaced relation to said outer casing and enclosing a crushing chamber having an upward current passage and an upper outlet for-fine material and a lower dropping opening for coarse material in communication with said settling chamber, and said casings having spaced walls between said outlet and said opening afiording up through, out over, down around, and in under said crushing chamber an endless current passage, crushing elements intermediate said outlet and said opening and within said crushing chamber,

for crushing material therein. drive means in op- L mb erative relation to said elements, for operating said elements, blower means in said endless passage, for causing a fluid current to flow up through, and out over, and down around said crushing chamber, and to return in under said crushing chamber, to float fine material into said settling chamber, material interceptor means across said passage for cleaning from such current fine material floating in such current, a fine material receiver below said interceptor, for receiving such fine material, and a coarse material receiver retainer -closed bottom wall for said crushing chamber,

below said endless passage and above said fine receiver, spaced below said dropping opening and inwardly of said interceptor means, and affording a bottom wall for said passage, and affording above said bottom Wall communication from said settling chamber to said crushing chamber for such current, for receiving material dropped through said opening and for retaining such material above said fine receiver and adjacent the path of such cleaned returning current.

6. In a pulverizer, an outer casing enclosing a settling chamber, an annular crushing die disposed in an approximately horizontal plane within and in spaced relation to said casing and having an inner crushing face afifording a crushing chamber having an upward current passage and an upper opening for discharging fine material and a lower opening for dropping coarse material, said openings in communication with said settling chamber and, said casing and die having spaced walls between said openings affording an endless current passage up through, out over, down around, and returning in under, said die, a rotatable crushing roll having a peripheral crushing face within and co-operating with said die to crush material between said faces, rotary means in operative relation to said roll, for rotating said roll, supply means in communication with said roll, for supplying material to be crushed by said roll, blower means in communication with said endless passage, for causing a fiuid current to circulate up through, out over, down around, and to return in under said die, to float fine ma terial into said settling chamber, a fine" material receptacle spaced around said dropping opening and in communication with said settling chamber for receiving such fine material from the latter, fine material interceptor means across said endless passage for cleaning from such current fine material floating in such current, and a coarse material receiver retainer closed bottom wall for such crushing chamber, below said endless passage and abov: said fine receiver, and inwardly of said cleaning means and spaced below said die and opposite said dropping opening, affording a closed top wall for said fine receiver and a closed bottom wall for said endless passage and aifording around said wall communication between said fine receiver and said settling chamber, for receiving such dropped material and retaining it above said fine receiver and in the path of such cleaned returning current.

'1, In a pulverizer, an outer casing enclosing a settling chamber, an inner casing within and in spaced relation to said outer casing and enclosing a crushing chamber having an upward current passage and an upper outlet for fine material and lower dropping opening for coarse materialcommunicating with said settling chamber, and said casings having spaced walls between said outlet and said opening afiording an endless current passage up through, out over, and down around, and returning in under, said crushing chamber,

crushing elements intermediate said opening and said outlet and within said crushing chamber, for

crushing material therein, operator means in operative relation to said elements, for operating said elements, supply means in communication with said elements, for supplying material'to be crushed by said elements, blower means in communication,

with said endless passage for causing a fiuid current to fiow up through, and out over, and down around, and to return in under, said crushing chamber, to float fine material into said settling chamber, a fine material receiver spaced around said opening and in communication with said settling chamber for receiving such fine material, material up-tossers below said dropping opening for .up-tossing such dropped material into said crushing chamber, and a coarse material retainer closed bottom wall for said crushing chamber, below said endless passage and above said fine receiver, and spaced inwardly of said fine receiver and below said up-tossers, spaced below said dropping opening and affording a bottom wall for said endless passage and a top wall for said fine receiver, and affording around said bottom wall communication between said settling chamber and said fine receiver, for retaining such dropped material above said fine receiver and adjacent said up-tossers and adjacent such returning current.

8. In a pulverizer, an outer casing enclosing a settling chamber, an annular crushing die disposed in an approximately horizontal plane within and in spaced relation to said casing and having an inner crushing face affording a crushing chamber having an upward current passage and an upper opening for discharging fine material and a lower opening for dropping coarse material, said openings in communication with said settling chamber and said casing and said die having spaced walls between said openings affording an endless current passage up through, out over, down around, and returning in under,,said die, a rotatable crushing roll having a peripheral crushing face within and co-operating with said die to crush material between said faces, rotary means in operative relation-to said roll for rotating said roll, supply means in communication with said roll, for supplying material to be crushed by said roll, blower means in communication with said passage for causing a fiuid current to circulate up through, out over, down around, and to return in under, said die, to float fine material into said settling chamber, a fine receptacle spaced around and below said dropping opening and in communication with said settling chamber for receiving such fine material from the latter, material up-tossers below said die and in the path of such dropped material, for uptossing the latter toward said die and a material retainer closed bottom wall for said crushing chamber, below said endless passage and above and spaced inwardly of said fine receiver and spaced below said die, and affording a closed bottom wall for said endless passage between said settling chamber to said dropping opening, and disposed opposite said dropping opening and below said up-tossers, and aifording a closed bottom wall for said up-tossers and a closed top wall for said fine receiver and affording around said wall a fine material communication from said settling chamber to said fine receiver, for retaining dropped material above said fine receiver and in the path of said up-tossers and adjacent such returning current.

9. In a pulverizer, an outer casing enclosing 'a settling chamber, an inner casing within and in spaced relation to said outer casing and enclosing a crushing chamber having an upward current passage and an upper outlet for fine material and a lower dropping opening for coarse material in communication with said settling chamber, said casing having spaced walls be tween said outlet and said opening and affording upthrough, out over, down around, and in under said crushing chamber an endless current passage, crushing elements intermediate said outlet and said opening and within said crushing chamber, for crushing material therein, drive means in operative relation to said elements, for operating said elements, blower means in communication with said endless passage, for causing a fluid current to flow up through, and out over, and down around said crushing chamber, and to return in under said crushing chamber, to float fine material into said settling chamber, material interceptor means without and around said crushing elements and across said passage for cleaning from such current fine crushed material floating in such current, and material uptossers below said crushing elements and below said dropping opening and below and inwardly of said cleaning means'for up-tossing such dropping material in the path of such cleaned returning current and up toward said crushing elements, and a closed material retainer bottom wall for said endless passage below and extended inwardly from said cleaning means and across said lower opening, below said up-tossers, for confining such cleaned returning current inwardly of said cleaning means and for receiving and retaining such dropped material adjacent said uptossers.

10. In a pulverizer, an outer casing enclosing a settling chamber, an annular crushing die disposed in an approximately horizontal plane within and in spaced relation to said casing and having an inner crushing face affording a crushing chamber having an upward current passage and having an upper opening for discharging fine material and a lower opening for dropping coarse material, said openings in communication with said settling chamber and said casings and die having spaced walls between said openings afiording an endless current passage up through, out over, down around and returning in under, said die, a rotatable crushing roll having a peripheral crushing face within and co-operating with said die to crush material between said faces, rotary means in operative relation to said roll, for rotating said roll, supply means in communication with said roll, for supplying material to be crushed by said roll, blower means in communication with said endless passage, for causing a fluid current to circulate up through, out over, down around, and to return in under, said die, to float fine material into said settling chamber, fine material interceptor means without and concentric of said die, and around such dropping opening and across said passage for cleaning from such current fine material floating in such current, and materialup-tossers below said die and inwardly of said cleaning means for uptossing into said die such dropping material in the path of such cleaned returning current, and a closed material retainer bottom wall for said endless passage below said cleaning means and extended inwardly from said cleaning means across and spaced below said lower opening and adjacent said uptossers, for confining such cleaned returning current inwardly of said cleaning means, and for receiving and retaining such dropped material adjacent said uptossers.

material'in communication with said settling chamber, and said casings having spaced walls between said outlet and said opening affording up through, out over, down around, and in under said crushing chamber an endless current passage, crushing elements intermediate said outlet and said opening and within said crushing cham-- ber, for crushing material therein, drive means in operative relation to said elements for operating said elements, blower means in communication with saidendless passage for causing a fluid currnt to flow up through, and out over, and down around saidcrushing chamber, and

to return in under said crushing chamber, to

float fine material into said settling chamber, material interceptor means without and around said crushing elements and across said passage for cleaning from such current fine material floating in such current, and a closed bottom material retainer wall below said crushing elements and inwardly of said cleaning means and below said current passage, spaced below said lower opening and afiording above said'closed bottom wall and below said crushing chamber communication between said settling chamber and said lower opening, and disposed below said cleaning means, for retaining such dropped material below said crushing elements and inwardly of and adjacent the path of such cleaned returning current.

12. In a pulverizer, a casing enclosing a pulverizing chamber having an upward current passage and an upper current outlet for fine material and a lower material dropping opening for coarse material affording a current inlet, conduit means in communication between said outlet and said inlet, said casing and said conduit means affording an endless current passage up through, out over, and down around said chamber, and returning in under said chamber, crushing elements in said chamber between said outlet and said inlet, operator for crushing material in said chamber, means in operative relation to said elements, for operating said elements, a blower in said endless passage, for causing a fluid current to flow up through said chamber and through said passage and return in under said chamber through said inlet, for floating crushed material from said chamber, and a vertically variable cross chamber partition wall within said I crushing chamber below and adjacent said upper outlet and spaced a variable distance above said crushing elements, and vertically variable to vary the space below said wall and above said crushing elements in which such material may be crushed by said crushing elements, to vary the fineness of such material crushed by said crushing elements in the path of such current, a fine material receiver around and spaced below said lower opening and in communication with said endless passage, for receiving such fine material therefrom, and a closed coarse material retainer bottom wall below said endless passage and intermediate said crushing elements and said flne receiver, and spaced from the receiver, for retaining such dropped coarse material above said fine receiver and for passing such fine material from said endless passage-to said fine receiver.

13. In a pulverizer, a casing enclosing a pulverizing chamber having an upward current passage and an upper current outlet for fine material and a lower material dropping opening for coarse material affording a current inlet, conduit means in communication between said outlet and said inlet, said casing and said conduit affording an endless current passage up through, out over, and down around said chamber, and returning in under said chamber, pulverizing elements in said chamber between said outlet and said inlet for pulverizing material in said chamber, operator means in operative relation to said elements for operating said elements, a blower in said endless passage for causing a fluid current to flow up through said chamber and through said passage and return in under said chamber through said inlet, for fioating fine material from said chamber, a vertically variable cross outlet wall within said chamber and below and adjacent said outlet and a variable distance above said crushing elements, afiording above it a vertically variable space through which such current may flow from such pulverizing chamber to said outlet, and affording below it a vertically variable crushing chamber for said crushing elements, a fine material receiver spaced below and around said lower opening, and in communication with said endless passage, for receiving such fine material therefrom, and a closed material retainer bottom wall below said endless passage, spaced below said lower opening and inwardly of and above said fine receiver, for returning such dropped coarse material above said fine receiver and for isolating such current from said fine receiver.

14. In a pulverizer, a casing enclosing a pulverizing chamber having an upward current passage and an upper current outlet for fine material and a lower material dropping opening for coarse material affording a current inlet, conduit means in communication between said outlet and said inlet, said casing and said conduit afiording an endless current passage up through, out over, and down around said chamber, and returning in under said chamber, pulverizing elements in said chamber between said outlet and said inlet for pulverizing material in said chamber, operator means in operative relation to said elements, for operating said elements, a blower in said endless passage for causing a fiuid current to flow up through said chamber and through said passage and return in under said chamber through said inlet, for floating fine material from said elements, an adjustable upwardly and outwardly extended partition wall within said chamber and below and adjacent said outlet and above said elements, affording around its outer edge a space through which such current may flow from said chamber to said outlet and afiording below it an upwardly and outwardly extended adjustable pulverizing chamber, and afiording above it a precipitation chamber, and affording inwardly of it a return outlet for precipitated particles, a fine material receiver spaced below said lower opening and in communication with said endless passage, for receiving such fine material from the latter, and a closed coarse material retainer wall below said endless passage and above fine receiver, and spaced below said dropping opening, for receiving coarse material dropping through said lower opening from said crushing elements, and for retaining such material above said fine receiver.

15. In a pulverizer, an outer casing enclosing a settling chamber, a non-rotary annular crushing die disposed in an approximately horizontal plane and having an inner annular crushing face affording a crushing chamber and having an upper outlet for discharging fine material and a lower opening for dropping coarse material, said casing and said die having spaced walls in communication between said outlet and said opening and affording an endless current passage up through, out over, down around, and returning in under, said die, a rotatable and revoluble crushing roll having a peripheral crushing face within and co-operating with said die to crush material between said faces, revoluble means in operative relation to said roll, for revolving said roll, supply means in communication with said roll, for supplying material to be crushed by said roll, blower means in communication with said endless passage, for causing a fluid current to circulate through said passage and fiow up through, out over, down around, and to return in under, said die, to float fine material from said die, fine material interceptor means around and concentric of said non-rotary die and across said endless passage, for cleaning from such current fine material in such current, a fine material receiver below and in communication with said cleaning means, for receiving fine material therefrom, and spaced below said lower opening, and a communication prevention material retainer bottom wall for said endless passage, and inwardly of said cleaning means and above said fine receiver, and spaced below said lower opening, for receiving coarse material dropping from said die through said lower opening, and for retaining such coarse material above said fine receiver.

16. In a pulverizer, an outer casing, a nonrotary crushing die disposed in an approximately horizontal plane within and in spaced relation to said casing and having an annular inner crushing face affording an upper outlet for dis-, charging fine material and affording a lower opening for dropping coarse material, said casing and die having spaced walls between said outlet and said opening and affording an endless current passage communicating up through, out over, down around, and returning in under, said die, a rotatable and revoluble crushing roll hav ing a peripheral crushing face within and cooperating with said die to crush material between said faces, revoluble means in operative relation to said roll, for revolving said roll, supply means in communication with said roll, for supplying material to be crushed by said roll, blower means in communication with said endless passage for causing a fiuid current to circulate through said passage and fiow up through, out over, down around, and to return in under, said die, to float fine material from said die, annular fine material interceptor means below said blower means and across said endless passage, for cleaning from such current fine material floating in such current, a fine material receiver below and in communication with said cleaning means, for receiving fine material from the latter, around and below said endless passage and below said lower opening, and a closed material retainer bottom wall below said endless passage and above said fine receiver, and spaced below said lower opening, for receiving coarse material dropping from said roll through said lower opening and for retaining such dropped material above said fine receiver.

17. In a pulverizer, an outer casing, a non-rotary crushing die disposed in an approximately horizontal plane within and in spaced relation to said casing and having an annular crushing face affording a crushing chamber and affording above it an upper current outlet and below it a lower current inlet, said casing and die having walls between and in communication with said outlet and said inlet affording an endless current passage communicating up through, out over, down around, and returning in under, said die, a rotatable and revoluble crushing roll having a peripheral crushing face within and co-operating with said die to crush material between said faces, revoluble means in operative relation to said roll for revolving said roll, supply means in communication with said roll, for supplying material to be crushed by said roll, blower means in com-- munication with said endless passage for causing a fluid current to circulate through said passage and flow up through, out over, down around, and to return in under, said die, to float fine material from said die, fine material interceptor means below said blower means and around said die and across said passage, for cleaning from such current intermediate said outlet and said inlet fine material floating in such current returning to said inlet, a fine material receiver below said lower inlet and below and in communication with said cleaning means, for receiving fine material from the latter, and a closed material retainer bottom wall for said endless passage below said endless passage and above said fine receiver and spaced below said die, for receiving material dropping through said die, and for retaining such material above said fine receiver.

18. In a pulverizer, an outer casing, a non-rotary crushing die disposed in an approximately horizontal plane within and in spaced relation to said casing and having an inner annular crushing face affording a crushing chamber and affording above it an upper current outlet and below it a lower current inlet, said casing and said die having spaced walls between said outlet and said inlet and affording an endless current passage communicating up through, out over, down around, and returning in under, s d die, a rotatable revoluble crushing roll havinga peripheral crushing face within and co-operating with said die to crush material between said faces, revoluble means in operative relation to said roll, for revolving said roll, supply means in communication with said roll, for supplying material to be crushed by said roll, blower means in said endless passage and above said die for causing a fluid current to circulate through" said passage and flow up through, out over, down around, and to return in under, said die, to float fine material from said die, fine material interceptor means below said blower means and across said passage intermediate said outlet and said inlet, for cleaning from such current between said blower means and said inlet fine material floating in such current returning to said inlet, a fine material receiver below and in communication with said cleaningmeans, for receiving fine material therefrom, spaced from and concentric of said die and below said endless passage, and a material retainer bottom wall for said endless passage spaced below said die and above said receiver, for receiving material dropping through said die and for retaining such material above said receiver.

19. In a pulverizer, an outer casing, a nonrotary crushing die disposed in an approximately horizontal plane within and in spaced relation to said casing and having an inner annular crushing face afiording a crushing chamber and affording above it an upper current outlet and below it a means in operative relation to saidroll, for revolving said roll, supply means in communication with said roll, for supplying material to be crushed by said roll, revoluble fan blades above and concentric of said die for causing a fluid current to circulate through said passage and flow up through, out over, down around, and to return in under, said die, to float fine material from said die, a fine receiver below said blades and concentric of said die, in communication with said passage, for receiving such fine material from said endless passage, and a closed material retainer inner top wall for said fine receiver, below said endless passage and spaced below said die, for receiving and retaining coarse material dropped from said die, and for isolating such returning current from said fine receiver.

20. In a pulverizer, an outer casing, a non-rotary crushing die disposed in an approximately horizontal plane within and in spaced relation to said casing and having an inner annular crushing face affording a crushing chamber and affording above it an upper current outlet and below it a lower current inlet, said casing and said die having spaced walls and affording an annular endless current passage communicating up through, out over, down around, and returning in under, said die, a rotatable and revoluble crushing roll having a peripheral crushing face within and co-operating with said die to crush material between said faces, revoluble means in operative relation to said roll, for revolving said roll, supply means in communication with said roll, for supplying material to be crushed by said roll, annular fine material interceptor means concentric of said die and across said passage intermediate of said outlet and said inlet for intercepting fine material floating in said passage, revoluble fan blades above and concentric of said cleaning means, revolving in said passage for causing a fluid current to circulate through said passage and flow up through, out over, and down around, said die, and through said cleaning means, and to return in under said die, to float fine material from said die and return cleaned fluid to said inlet, fine material receiver means below and in communication with said cleaning means for receiving fine material from the latter, and a closed material retainer wall spaced below said die, below said endless passage and above said fine receiver, for receiving coarse material dropped from said die and for retaining such material above said fine receiver.

GEORGE HOLT FRASER.