US3614000A - Method for the comminution of particulate solid materials - Google Patents

Method for the comminution of particulate solid materials Download PDF

Info

Publication number
US3614000A
US3614000A US3614000DA US3614000A US 3614000 A US3614000 A US 3614000A US 3614000D A US3614000D A US 3614000DA US 3614000 A US3614000 A US 3614000A
Authority
US
United States
Prior art keywords
particles
fluid
chamber
grinding
mill
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
Other languages
English (en)
Inventor
George E K Blythe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
GEORGE E K BLYTHE
Original Assignee
GEORGE E K BLYTHE
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by GEORGE E K BLYTHE filed Critical GEORGE E K BLYTHE
Application granted granted Critical
Publication of US3614000A publication Critical patent/US3614000A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
    • B04C9/00—Combinations with other devices, e.g. fans, expansion chambers, diffusors, water locks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
    • B01F25/30—Injector mixers
    • B01F25/31—Injector mixers in conduits or tubes through which the main component flows
    • B01F25/312—Injector mixers in conduits or tubes through which the main component flows with Venturi elements; Details thereof
    • B01F25/3123—Injector mixers in conduits or tubes through which the main component flows with Venturi elements; Details thereof with two or more Venturi elements
    • B01F25/31233—Injector mixers in conduits or tubes through which the main component flows with Venturi elements; Details thereof with two or more Venturi elements used successively
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C19/00—Other disintegrating devices or methods
    • B02C19/06—Jet mills
    • B02C19/061—Jet mills of the cylindrical type
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C19/00—Other disintegrating devices or methods
    • B02C19/06—Jet mills
    • B02C19/063—Jet mills of the toroidal type
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C23/00—Auxiliary methods or auxiliary devices or accessories specially adapted for crushing or disintegrating not provided for in preceding groups or not specially adapted to apparatus covered by a single preceding group
    • B02C23/18—Adding fluid, other than for crushing or disintegrating by fluid energy
    • B02C23/24—Passing gas through crushing or disintegrating zone
    • B02C23/32—Passing gas through crushing or disintegrating zone with return of oversize material to crushing or disintegrating zone
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23K—FEEDING FUEL TO COMBUSTION APPARATUS
    • F23K1/00—Preparation of lump or pulverulent fuel in readiness for delivery to combustion apparatus
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/30—Mixing gases with solids
    • B01F23/32—Mixing gases with solids by introducing solids in gas volumes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23K—FEEDING FUEL TO COMBUSTION APPARATUS
    • F23K2201/00—Pretreatment of solid fuel
    • F23K2201/10—Pulverizing
    • F23K2201/1006—Mills adapted for use with furnaces

Definitions

  • lfrovisionis made for recycling the oversized particles efl'her to the aforementioned multistage Venturi system or to a similar but separate system for regrinding and reintroduction into the chamber.
  • the general purpose of the process and the apparatus provided by the invention is so to modify the condition of materials as to facilitate handling, packaging, dispensing or use, or/and to enhance the properties or quality of the same.
  • materials comminuted by the method and apparatus of the invention may include pharmaceuticals, including insecticides such as D.D.T., cosmetics, plastics, solid lubricants, pigments for paints and metal-coating, and metal powder for powder metallurgy.
  • Another group of materials capable of being so dealt with comprises combustible fuels such as coal and colloidal fuel, wood flour, husks and the like.
  • soil nutrients rock, urea formaldehyde and ash may with advantage be comminuted to a pulverulent form by the method and apparatus of this invention.
  • An object of the present invention is to provide a generally improved and efficient process of comminuting particulate material to a pulverulent form of micron or fractional micron size, as will be hereinafter described.
  • Another object of the invention is to out this process, a novel form of mechanical moving parts.
  • the process according to this invention consists in generating a high velocity stream of high pressure fluid, raising the said velocity to a peak value and thereon permitting expansion of the fluid and consequent conversion to kinetic energy of the potential energy of compression thereof in a multistage Venturi system wherein the fluid is increased in velocity and permitted to expand a plurality of times, introducing particulate material transversely into the high velocity stream of fluid at the point where the latter is-permitted to expand for the first time, the material and the fluid being thereby so thoroughly intermixed as to result in self-attrition of particles by impact, injecting the mixture of fluid and entrained particulate material into a chamber, constraining the said mixture to follow a curved path within the chamber so as toeffect separation and classification of particles of different sizes within the mixture following said path, diverting from the chamber the outermost portion of the mixture following said path thereby removing particles above a certain predetermined range of sizes from the chamber, introducing said removed portion transversely into either the said high velocity stream of fluid flowing through the multistage Venturi system or into
  • the grinding fluid employed may be compressed air or, for oxidizable or combustible materials, any appropriate inert gas under pressure.
  • the said fluid may consist of superheated steam.
  • a multistage Venturi system is meant one having two or more stages.
  • the size reduction of particles may take place wholly or principally in the Venturi system. It is, however, also possible for the particles to be only preliminarily rough ground in the Venturi system and finely ground within the mill chamber. ln the both cases the oversized particles may advantageously be recycled either to the Venturi grinding zone or to an entirely separate multistage Venturi system for regrinding.
  • a fluid velocity of the sonic to supersonic order of about 1000 feet/second is usually necessary in order that the rate of supply of the raw material into the grinding zone or zones may be of a reasonable order of magnitude and yet satisfy the condition that in the interests of efficiency the mass of raw material supplied per unit time and the mass rate of supply of the grinding fluid are to be comparable.
  • a sonic to supersonic flow of fluid is typical of what is meant by the expression a high velocity.
  • Such high velocities require that the rate of supply of material into the grinding zone or zones shall be maintained at a high and substantially uniform level; otherwise there will be short periods of time during which the fluid stream is overloaded and the velocity of the combined stream (when the relative velocity of fluid and material has fallen to zero, that is to say the velocity imparted to the material particles) is consequently small, while for the remaining periods the stream is running light and although the material particles attain high velocities the mass of material supplied per unit time is much smaller than it need be.
  • Comminution, classification and collection of particulate material in a grinding mill is achieved by producing in various parts of the mill various patterns of hydrodynamic flow, vortex motion, turbulence and possible shock-fronts, so that a solid particle makes a large number of collisions. These conditions are effected in the mill by suitable dispositions of nozzles, appropriate design of solid boundary surfaces and regulation of the pressure and temperature of the incoming high velocity fluid, the particles having had imparted to them as high an energy of collision as possible consistent with their remaining frangible.
  • the particles and grinding fluid leaving the classification region may be directed along paths which produce further size classification by the effects of hydrodynamic forces and gravity.
  • particles of different sizes may be distributed starting sharply at a predetermined maximum size, with a continuous distribution of smaller sizes.
  • An important aspect of the process of this invention is that recycling is used to quickly transfer large solid particles from certain parts of the mill to regions where they are subjected to further grinding.
  • a particulate material injector of the special form hereinafter to be described may advantageously be employed, such an injector functioning not only to effect intense mixing of the material and the fluid but also to produce part of the grinding effect by causing collisions of the solid particles.
  • the material injector provides a mixing chamber for the grinding fluid and the infed particulate solid material, the high velocity conveying stream of fluid being so thoroughly intermixed with the said material as to result in self-attrition of particles by impact and a consequent reduction of particle size.
  • the particulate material injector of the special form mentioned consists, of a Venturi injector adapted to be fitted to a mill chamber and comprising at least (i) an input jet through which a high velocity stream of grinding fluid in the form of pressurized air or other gas or superheated steam can flow and having adjacent thereto an inlet for feeding into the injector the particulate material to be ground, the interior of the jet first tapering to a comparatively narrow throat designed to raise to a peak value the velocity of the grinding fluid flowing therethrough and then flaring outwardly to a substantially larger diameter to permit of expansion of the fluid and consequent conversion to kinetic energy of the potential energy of compression thereof and (ii) a coaxial Venturi tube or nozzle having a tapering portion into which the input jet leads and a flared portion connected or for connection to or with the chamber.
  • the mill chamber may advantageously be shaped to provide an endless path and is fitted with a plurality of subsidiary compressed air (or other gas) or superheated jets or nozzles.
  • a mill is aptly termed a jet energy mill, the subsidiary fluid jets or nozzles extending tangentially or substantially so with respect to the endless flow path and functioning to generate within the mill chamber a fluid vortex motion rather than a linear stream.
  • FIG. 1 is a vertical sectional view of a two-stage Venturi product injector combined with a mill chamber of shallow cylindrical or pan form, hereinafter to be described,
  • FIG. 2 is a plan view of the apparatus shown in FIG. 1,
  • FIG. 3 is a purely diagrammatic plan view representing the main large vortex and the smaller vortices formed in the mill chamber illustrated in FIGS. 1 and 2,
  • FIG. 4 is a diagrammatic elevational view of the same chamber depicting a secondary circulation designed to bring about automatic size-classification of solid particles
  • FIG. 5 is an elevational view of one complete apparatus including a jet energy mill chamber in the form of a vertically disposed race-track" torus,
  • FIG. 6 is a diagram, partly in section, illustrating one way in which oversized particles can be scooped out from the mill chamber and fed back into the two-stage input Venturi injector for further grinding therein,
  • FIG. 7 is a diagram illustrating the manner in which double Venturi product injectors can be arranged in series in conjunction with centrifugal classifiers also in series,
  • FIG. 8 is a vertical sectional view illustrating an apparatus for collection by cyclone of very fine solid particles in a twostage process
  • FIG. 9 is a detail cross-sectional view taken on the line IX- IX of FIG. 8,
  • FIG. 10 is a vertical sectional view of a particle size-classification mechanism adapted to function on the elutriation principle hereinafter to be defined,
  • FIG. 11 is a flow diagram schematically outlining a typical cycle of operations within the broad process of this invention.
  • FIGS. 12, 13 and 14 are graphs illustrating the economics of the invention in relation to the grinding of coal to micron size particles and to the burning of such micron sized coal with finite excess air, e.g. for generating steam,
  • a Venturi product injector is indicated generally at I, this being combined with a mill chamber MC of shallow cylindrical or pan form.
  • the injector I comprises, in combination, a Venturi inputjet 1 and a coaxial Venturi combining tube or nozzle 2.
  • a high velocity stream of grinding fluid in the form of pressurized air or other gas or superheated steam flows into the injector I, via an inlet tube 3, and from thence through the input jet 1.
  • the interior of this jet first tapers at 1a to a comparatively narrow throat lb designed to raise to a peak value the velocity of the grinding fluid flowing therethrough and then flares outwardly at 10 to a substantially larger diameter to permit of expansion and consequent conversion to kinetic energy of the potential energy of compression of the fluid.
  • the efficient expansion portion of the inputjet 1 leads into the combining tube or nozzle 2 and since the latter also first tapers at 2a to a comparatively narrow throat 2b and then flares outwardly at 2c there is provided a twostage Venturi injector.
  • the particulate material to be ground to micron or fractional micron size is fed laterally and tangentially into the high velocity fluid stream through a tangential inlet 4 in a hollow cylindrical body 5 within which the input jet 1 is accommodated.
  • This inlet 4 may, as shown, have secured thereto a suitably fluted adapter 6 (see FIG. 2) on to which can be fitted a feed tube or pipe for the material.
  • the arrangement is such that the said material is entrained in the high velocity fluid stream emerging from the jet 1 at a location where the fluid is being permitted to expand after having passed through the narrow throat lb of the jet.
  • the velocity of the fluid and the entrained particulate material is increased as the fluid and the particles therein pass through the narrow throat 2b of the combining tube or nozzle 2 wherein intense mixing and grinding takes place to effect size reduction of particles.
  • the particular injector I illustrated includes a cap 7 for the hollow cylindrical body 5 in the center of which cap is fitted the inlet tube 3 for the grinding fluid which latter flows both through the jet 1 and the coaxial combining tube or noule 2.
  • the appropriate end of the said body 5 may be externally screwthreaded as at 5a to receive a correspondingly internally threaded flange 8 by means of which the injector can be supported or fixed in position.
  • the selection of the material of which the input jet I is made is important since it must not be easily abraded.
  • the material injector I merely functions as a preliminary rough grinder, the remainder of the mill, i.e. the mill chamber MC in the illustrated case, performing both the functions of fine grinding and size classification in one continuous operation without recycling to the injector.
  • the mill chamber MC of shallow cylindrical or pan form is a grinding zone of a jet energy mill as hereinbefore defined inasmuch as it provides a circular endless path and is formed with a plurality of subsidiary compressed air (or other gas) jet orifices 9.
  • the latter extend tangentially or substantially so with respect to the circular endless flow path and function to generate within the mill chamber MC smaller vortices 10 which are near the chamber walls and on the outside ofa large main vortex 11 in the central region of the chamber (see FIG. 3).
  • annular feed manifold 13 into which feeds the stream of intermixed high velocity grinding fluid and preliminarily ground particles flowing out of the outwardly flared portion 20 of the combining tube or nozzle 2.
  • This stream flows into the feed manifold 13, via a funnel I4, and from thence into the mill chamber MC through feed inlets formed through the chamber top 12.
  • a gaseous fluid pressure manifold i.e. annular pressure belt, 16 into which compressed air or other gas flows through an inlet 17 and from thence into the chamber through the tangentially extending jet orifices 9.
  • a gaseous fluid outlet 18 extends coaxially from the chamber top 12.
  • a concentric cyclone collector 19 collects the ground particles which are deposited in a bin 20.
  • a suitably arranged outlet (not shown) connects the periphery of the mill chamber MC with the injector l.
  • the simple jet orifices 9 may, if desired, be replaced by Venturi jets.
  • the axes of such jet orifices or Venturi jets (of which any appropriate number may be provided) are parallel to the bottom of the shallow cylindrical chamber MC and inclined nearly tangentially with respect to the circular section of the cylinder.
  • the fluid in close contact with the chamber walls is at rest.
  • a large vortex 11 is formed in the central region of the chamber and smaller vortices 10 near the walls (FIG. 3). The small vortices ensure that a solid particle will make many collisions with its fellows.
  • the secondary circulation continually carries solid particles back to the grinding zones near the jet orifices 9 or Venturi jets, i.e. near to the walls where speeds are high and turbulence is at a maximum.
  • the fact that the secondary circulation is inward near the top of the chamber provides a size-classification mechanism. This is because the inward force acting on a particular solid particle in this region as a result of the action of the flow thereon is related to the area which it presents to the flow at any instant. This force varies from the first power, the square of the radius of a disc or a sphere which would present the same area to the flow at that instant.
  • fluid vortex generated within the mill chamber can thus be divided roughly into three parts, viz an outermost part constituting a grinding or reduction zone, an inner part being a withdrawal zone and an intermediate part constituting the classification zone.
  • the fluid and solid material are maintained in a well mixed condition, and that the fluid velocity changes rapidly with time and place so that a particle is likely to collide frequently with other particles of different velocities.
  • the main vortex ll acts as a flywheel" to smooth out irregularities arising from nonuniform feeding of the particulate material into the grinding or reduction zone.
  • an important feature of the mill is that not only does the above-mentioned size classification mechanism prevent the oversized particles from reaching the output, but the existence of the secondary circulation (FIG. 4) ensures that these oversized particles are automatically carried back to the grinding zones.
  • a typical particle may have to pass many times through the grinding zones before it attains the desired size, and it may also be subjected several times to the recycling process described above.
  • the mill chamber is constituted by a pair of coaxial cylinders, the annular gap between these cylinders defining the chamber, collection of the product taking place near the inner of the cylinders.
  • a mill chamber in the shape of a hollow torus is satisfactory, collection taking place at the inner side of such torus.
  • race-track shape torus i.e. two half-toruses connected by straight portions.
  • the latter design has the advantage that it can be fabricated and joined up as lengths of pipe.
  • the geometrical form of a jet energy mill chamber may vary widely and may include even a serpentine form. Whilst the simplest form is probably a shallow cylindrical chamber or pan, such as that shown in FIGS. 1 and 2, other geometries are about as efficient and sometimes easier to make.
  • the toms or race-track can be of circular section, fabricated of pipe, or of square or trapezoidal section fabricated of sheet.
  • FIG. 5 One complete apparatus embodying the invention is illustrated, merely by way of example, in FIG. 5.
  • This apparatus comprises, in combination, a jet energy mill in the form of a vertically disposed race-track torus: a two-stage Venturi product injector l of the form hereinbefore described with reference to FIG.
  • a feed funnel 21 for particulate material for particulate material
  • a Venturi feed injector 22 at the bottom of said funnel an infeed pipe 23 extending from the feed injector 22 into the bottom half-torus 24; tangential nozzles or jets 25 fitted to the bottom half-torus; a high velocity fluid manifold 26 having connections 27 with the two-stage Venturi injector I, the feed injector 22 and the tangential nozzles or jets 25;
  • the multistage Venturi injector I is to function as a preliminary grinder for particulate material being introduced into the race-track" torus RT, then there would be provided an inlet for introducing such material into the hollow body 5 of the said injector.
  • the Venturi type feed injector 22 could be dispensed with and the injector I wholly relied on for feeding particulate material into the mill. Or the injector could still be used as a further means of introducing particulate material into RT. That is to say, the injector 22 in this particular apparatus is optional.
  • FIG. 6 This scooping out technique is diagrammatically illustrated in FIG. 6 as applied to a recycling tubular bend 33 ofa jet energy mill chamber of toms form.
  • the outer and inner wall portions of the semicircular bend 33 are indicated by the numerals 33a and 33b respectively.
  • a two-stage Venturi injector I generally of the form described with reference to FIG. I is fitted on the torus-with the combining tube or nozzle 2 extending down thereinto.
  • Extending slidably into and chordally across the outer portion of bend 33 is a scoop member 34. Widthwise, i.e. in a direction at right angles to its length, the member 34 extends right across the section of the bend 33.
  • the inner leading end 34a of the scoop member 34 faces the upwardly swept oncoming intermixed stream of high velocity gaseous fluid and solid particles.
  • the scoop member 34 is longitudinally adjustable inwardly and outwardly (as indicated by the chain lines) by any appropriate mechanism to vary the size of the opening between the outer wall portion 33a and the leading end 34a of the member. In this way, the said member functions as a divider to scoop out" the larger or heavier solid particles from the bend, allowing the smaller and lighter particles to pass around the bend undisturbed.
  • the size of the opening 0 determines which size or sizes of solid particles within the range concerned shall be scooped out.
  • the scooped-out particles are drawn into a pipe 35 through which they are fed tangentially into the hollow cylindrical body of the two-stage Venturi injector I.
  • the said oversized particles are accordingly reduced by regrinding in the injector I and thereupon immediately reintroduced into the torus through the combining tube or nozzle 2.
  • the paths taken by the heavier and the lighter solid particles are indicated by arrows.
  • the two-stage Venturi injector I may be either one through which the particulate material is originally introduced into the mill chamber, or one which is entirely separate from the material feed and is wholly reserved for the recycling process.
  • the injector I shown in FIG. 5 may be reserved for recycling only in which instance the Venturi feed injector 22 may be the only means of feeding particulate material into the "race-track torus RT.
  • a jet energy mill may readily combine in one unit the separate operations of grinding, classification of sizes, return of oversize particles to the grinding zone or zones, and collection of the pulverulent product of micron or fractional micron fineness.
  • the idea in this regard is that various portions of the vortex can be made to perform all these functions.
  • FIG. 7 it is within the scope of the invention to provide a plurality of two-stage Venturi particulate material injectors I which are arranged in parallel, i.e. cell formation, for link-up" with centrifugal classifiers (not shown) also arranged in parallel.
  • a supply of compressed air enters, at 36, a compressed air manifold 37, the common particulate material feed pipe being indicated at 38 and the individual material inlets at 39.
  • the particulate material is entrained in the compressed air and, after being ground, either preliminarily or finally, in the Venturi injectors l, passes from the latter, via pipes 40 into a ground material manifold 41 which is linked up with the centrifugal classifiers.
  • a cyclone collector is shown at 19 in FIG. I and at 30 in FIG. 5. It is convenient here to mention that the standard cyclone collector is a typical example of the proper design of solid boundaries to produce desirable effects of hydrodynamic flow. Thus, if a mixture of gas and solid particles is fed nearly tangentially into a tube of conical form, the forces on a solid particle are directed towards the point of the cone defined by this tube, thus achieving separation. This is one of the established scientific laws upon which the design of a grinding mill according to this invention is based.
  • the efficiency of collection by cyclone of very fine particles suspended in a gas can be improved by making it a two-stage process.
  • the effective radius of the particles can be increased and their effective density lowered by providing an atomized water-spray (to give droplets of suitable size) near the wide end of the conical cyclone.
  • the droplets in such a case are driven towards the point of the cone by the ordinary cyclone forces referred to above, and sweep up the fine solid particles during their travel.
  • the droplets pass through a heated zone provided by a steamjacket, the water evaporating, but the solid particles still being riven towards the point of the cone by the cyclone forces and entering the collector as a dry product.
  • FIGS. 8 and 9 A two-stage collection by cyclone of ground and classified particles of micron or fractional micron fineness is illustrated in FIGS. 8 and 9.
  • MC in FIG. 8 is depicted a mill chamber of shallow cylindrical or pan form similar to that already described herein. Mounted on this chamber (but omitted from FIG. 8 for simplicity in illustration) is a two-stage Venturi particulate material injector.
  • a cyclone collector having a lower end portion 42a of a conical form and an outlet 43 for ground particles (dust).
  • Surrounding the collector 42 is a steam jacket 44 into which steam generated, in a boiler (not shown), is led via inlets 45.
  • the condenser inlet is indicated at 56, and the condensate level 57 is arranged to control the feed to the condenser.
  • the arrowed vertical dotted line 58 in FIG. 8 represents a connection between the boiler and the condenser 55.
  • the .water droplets as previously mentioned, are driven downwards towards the lower end of the conical portion 42a and sweep up the ground fine solid particles. Moreover, the water of the droplets evaporated by virtue of the collector walls being heated up steam containedjn the steam jacket 44, leaving the fine solid particles in a dry condition as they are driven from the outlet 43 by the cyclone forces.
  • a particle of just above the aforementioned critical effective radius can, as the result of a collision, be broken into two (or more) fragments which may be very different in size. These fragments are now all below the critical size and are therefore eventually carried out though the outlet.
  • paints, powder metallurgy, plaster such a distribution, with nothing above a certain effective radius but with all sizes below that represented, can be described as ideal, but in other applications the very smallest particles would be wasted.
  • FIG. 11 A typical flow diagram relating to a complete apparatus for the comminution of particulate solid materials in accordance with this invention is illustrated in FIG. 11.
  • the letter a indicates raw material; the letter 1; indicates mechanical grinding and sieving; 0 indicates particulate feed material; a a two-stage Venturi grinder and injector; e preliminary rough ground material;ffluid jet energy mill classification; g small particles; h medium particles; ilarge panicles;j an outer takeoff by which large particles are returned to the two-stage Venturi grinder and injector d; k fluid jet energy grinding zone; and [fine particles the larger ones of which are recycled to g by an innertakeoff at m whilst the remainder pass at n into a cyclone collector.
  • Tea leaves or other particulate foodstuffs initially of about one-eighth inch maximum dimension can be reduced to particles of from 3-4 microns.
  • Pigments (for paints) initially ofa size conforming to 100 mesh B.S.S. can be reduced to particles of 0.1 micron.
  • FIG. 11 schematically outlines the cycle of operations which accounts, in part only, for the substantial improvement in operating costs compared with the use of an external supply of energy.
  • Micron coal with finite excess air can, as will be appreciated from a consideration of FIGS. 12, 13 and 14 be used for generating steam at thermal efficiency upwards of 92 percent. Additionally, the fullest possible use may be made of the sensible heat remaining in the waste products of combustion for the purpose of preheating the compressed air from atmospheric temperature of 60 F. to 260 F. This results in a most advantageous increase in the pressure or volume of the air used to reduce the coal fed to the fluid energy mills to produce coal particles of one micron, thereby deriving simultaneously the proved benefits resulting from the use of preheated air for direct combustion purposes.
  • Use can also be made of the remaining volume of waste products of combustion to transmit, at normal performance, their sensible heat content to the boiler feed water, such as will ensure under normal working conditions an increase in temperature from atmospheric at 60 F. to 180 F.
  • the axis of abscissas (x) is marked to designate the mean diameter of particles in microns, whereas the axis of ordinates (y) is marked to shown the integral percentage by weight-all when grinding coal in a mill.
  • solid line curves relate to coal extract, the dotted curve to British bituminous coal and the chain line curves to German fine coal.
  • the steep curves at the left-hand side of the graph relate to micronized coals and, for purpose of comparison, the less steep curves relate to conventionally pulverized coals.
  • FIGS. 13 and 14 relate to the burning of micronized coal.
  • FIG. 13 is a graph concerned with minimum burning times at microns.
  • the x axis is marked to show air-coal ratio-V GO (Nm lKg), whereas the y axis is marked in seconds of burning time.
  • FIG. 14, is a graph concerned with maximum burning temperatures at 10 microns, the x axis being designated V GO (Nm /Kg) and the y axis being designated TP(K.).
  • Comminuting apparatus of this invention may, ifdesired, be incorporated in, or combined with, any other appropriate plant or apparatus for progressively reducing the size of comparatively large pieces, rocks or the like of raw material and thus converting the latter into a particulate form suitable for pulverizing by the improved process of the invention.
  • This invention includes, as a feature, a comminuted product of micron or fractional micron fineness produced by the herein described process.
  • a process of comminuting a particulate material to a pulverulent form of micron or fractional micron size which comprises generating a high velocity stream of high pressure fluid

Landscapes

  • Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Disintegrating Or Milling (AREA)
  • Crushing And Grinding (AREA)
US3614000D 1968-06-19 1969-06-12 Method for the comminution of particulate solid materials Expired - Lifetime US3614000A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2908368 1968-06-19

Publications (1)

Publication Number Publication Date
US3614000A true US3614000A (en) 1971-10-19

Family

ID=10285888

Family Applications (1)

Application Number Title Priority Date Filing Date
US3614000D Expired - Lifetime US3614000A (en) 1968-06-19 1969-06-12 Method for the comminution of particulate solid materials

Country Status (8)

Country Link
US (1) US3614000A (zh)
BE (1) BE734700A (zh)
CH (1) CH497203A (zh)
DE (1) DE1930464A1 (zh)
ES (1) ES368500A1 (zh)
FR (1) FR2011252A1 (zh)
GB (1) GB1238541A (zh)
NL (1) NL6909405A (zh)

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3726483A (en) * 1970-12-30 1973-04-10 Daikin Ind Ltd Process the preparation of ultra-fine polytetrafluoroethylene molding powder
US3895760A (en) * 1973-05-18 1975-07-22 Lone Star Ind Inc Method and apparatus for shattering shock-severable solid substances
US4198004A (en) * 1978-05-05 1980-04-15 Aljet Equipment Company Jet mill
US4391411A (en) * 1980-12-18 1983-07-05 Process Development Corporation Method and apparatus for pulverizing materials by vacuum comminution
US4452911A (en) * 1983-08-10 1984-06-05 Hri, Inc. Frangible catalyst pretreatment method for use in hydrocarbon hydrodemetallization process
US4454018A (en) * 1983-04-14 1984-06-12 Mobil Oil Corporation Simultaneous crushing and retorting of oil shale with fluid jets
US4504017A (en) * 1983-06-08 1985-03-12 Norandy, Incorporated Apparatus for comminuting materials to extremely fine size using a circulating stream jet mill and a discrete but interconnected and interdependent rotating anvil-jet impact mill
US4546925A (en) * 1983-09-09 1985-10-15 General Electric Company Supermicronized process for coal comminution
US4880170A (en) * 1989-01-03 1989-11-14 Gte Products Corporation Process for producing fine copper powder with enhanced sinterability
US5392997A (en) * 1993-12-08 1995-02-28 Comensoli; Inaco Non-impact pulverizer and method of using
US5765766A (en) * 1994-12-08 1998-06-16 Minolta Co., Ltd. Nozzle for jet mill
US6402068B1 (en) 1998-08-06 2002-06-11 Avrom R. Handleman Eductor mixer system
US20030147767A1 (en) * 2002-01-22 2003-08-07 Ivan Calia Barchese Method of producing tablets formed by prealloys of aluminum-iron produced from automized powders, and tablets produced thereby
US20110210193A1 (en) * 2010-02-26 2011-09-01 Robert Sly Disc mill assembly for a pulverizing apparatus
US20140034766A1 (en) * 2012-08-03 2014-02-06 Aurora Office Equipment Co., Ltd Shanghai Cooled motor for a paper shredder
JP2016097371A (ja) * 2014-11-25 2016-05-30 日本ニューマチック工業株式会社 粉砕集塵装置
JP2016097376A (ja) * 2014-11-25 2016-05-30 日本ニューマチック工業株式会社 ジェット粉砕機
CN112354656A (zh) * 2020-10-21 2021-02-12 中鸿纳米纤维技术丹阳有限公司 一种纳米级颗粒的粉碎加工用纳流化床结构
CN113546739A (zh) * 2020-04-24 2021-10-26 北矿机电科技有限责任公司 一种废旧动力电池破碎装置及方法
US11154869B2 (en) * 2019-01-30 2021-10-26 Henan Polytechnic University Device for pulverization and explosion suppression of low carbon gas hydrate
WO2022060732A1 (en) 2020-09-17 2022-03-24 Nanophase Technologies Corporation Magnetic beads, method of making and method of use thereof
CN114225790A (zh) * 2021-12-16 2022-03-25 黄俊生 一种多自由度检验科用血液混匀装置
CN116672965A (zh) * 2023-06-08 2023-09-01 河北诚成肥业股份有限公司 一种化肥滚筒造粒用喷射装置

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105268268B (zh) * 2015-04-21 2017-03-15 四川展祥特种合金科技有限公司 一种立式组合高效脱硫脱氨除尘装置
CN113597896B (zh) * 2021-07-23 2022-11-25 碧奥能源(上海)有限公司 一种生物质能源秸秆处理设备
CN114345508B (zh) * 2022-03-18 2022-06-07 山西金山磁材有限公司 一种能改善粉末粒径分布的气流磨分选装置与方法
CN115845975B (zh) * 2022-10-24 2023-05-26 邯郸学院 一种高分子化学材料颗粒的多级研磨装置

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2846150A (en) * 1955-09-29 1958-08-05 Texaco Development Corp Fluid energy grinding
US3467317A (en) * 1966-09-26 1969-09-16 Fluid Energy Process Equip Fluid energy grinding method and means
US3491953A (en) * 1967-01-09 1970-01-27 Fluid Energy Process Equip Treatment of granular solids by fluid energy mills

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2846150A (en) * 1955-09-29 1958-08-05 Texaco Development Corp Fluid energy grinding
US3467317A (en) * 1966-09-26 1969-09-16 Fluid Energy Process Equip Fluid energy grinding method and means
US3491953A (en) * 1967-01-09 1970-01-27 Fluid Energy Process Equip Treatment of granular solids by fluid energy mills

Cited By (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3726483A (en) * 1970-12-30 1973-04-10 Daikin Ind Ltd Process the preparation of ultra-fine polytetrafluoroethylene molding powder
US3895760A (en) * 1973-05-18 1975-07-22 Lone Star Ind Inc Method and apparatus for shattering shock-severable solid substances
US4198004A (en) * 1978-05-05 1980-04-15 Aljet Equipment Company Jet mill
US4391411A (en) * 1980-12-18 1983-07-05 Process Development Corporation Method and apparatus for pulverizing materials by vacuum comminution
US4454018A (en) * 1983-04-14 1984-06-12 Mobil Oil Corporation Simultaneous crushing and retorting of oil shale with fluid jets
US4504017A (en) * 1983-06-08 1985-03-12 Norandy, Incorporated Apparatus for comminuting materials to extremely fine size using a circulating stream jet mill and a discrete but interconnected and interdependent rotating anvil-jet impact mill
US4452911A (en) * 1983-08-10 1984-06-05 Hri, Inc. Frangible catalyst pretreatment method for use in hydrocarbon hydrodemetallization process
US4546925A (en) * 1983-09-09 1985-10-15 General Electric Company Supermicronized process for coal comminution
US4880170A (en) * 1989-01-03 1989-11-14 Gte Products Corporation Process for producing fine copper powder with enhanced sinterability
US5392997A (en) * 1993-12-08 1995-02-28 Comensoli; Inaco Non-impact pulverizer and method of using
US5765766A (en) * 1994-12-08 1998-06-16 Minolta Co., Ltd. Nozzle for jet mill
US6402068B1 (en) 1998-08-06 2002-06-11 Avrom R. Handleman Eductor mixer system
US20030147767A1 (en) * 2002-01-22 2003-08-07 Ivan Calia Barchese Method of producing tablets formed by prealloys of aluminum-iron produced from automized powders, and tablets produced thereby
US7033414B2 (en) * 2002-01-22 2006-04-25 Ivan Calia Barchese Method of producing tablets formed by prealloys of aluminum-iron produced from automized powders, and tablets produced thereby
US20110210193A1 (en) * 2010-02-26 2011-09-01 Robert Sly Disc mill assembly for a pulverizing apparatus
US8893993B2 (en) 2010-02-26 2014-11-25 Reduction Engineering, Inc. Methods for pulverizing materials
US8282031B2 (en) * 2010-02-26 2012-10-09 Reduction Engineering, Inc. Disc mill assembly for a pulverizing apparatus
US10814332B2 (en) 2012-08-03 2020-10-27 Aurora Office Equipment Co., Ltd. Shanghai Cooled motor for a paper shredder
US9088183B2 (en) * 2012-08-03 2015-07-21 Aurora Office Equipment Co., Ltd Shanghai Cooled motor for a paper shredder
US20140034766A1 (en) * 2012-08-03 2014-02-06 Aurora Office Equipment Co., Ltd Shanghai Cooled motor for a paper shredder
JP2016097371A (ja) * 2014-11-25 2016-05-30 日本ニューマチック工業株式会社 粉砕集塵装置
JP2016097376A (ja) * 2014-11-25 2016-05-30 日本ニューマチック工業株式会社 ジェット粉砕機
US11154869B2 (en) * 2019-01-30 2021-10-26 Henan Polytechnic University Device for pulverization and explosion suppression of low carbon gas hydrate
CN113546739A (zh) * 2020-04-24 2021-10-26 北矿机电科技有限责任公司 一种废旧动力电池破碎装置及方法
WO2022060732A1 (en) 2020-09-17 2022-03-24 Nanophase Technologies Corporation Magnetic beads, method of making and method of use thereof
CN112354656A (zh) * 2020-10-21 2021-02-12 中鸿纳米纤维技术丹阳有限公司 一种纳米级颗粒的粉碎加工用纳流化床结构
CN114225790A (zh) * 2021-12-16 2022-03-25 黄俊生 一种多自由度检验科用血液混匀装置
CN114225790B (zh) * 2021-12-16 2023-10-13 黄俊生 一种多自由度检验科用血液混匀装置
CN116672965A (zh) * 2023-06-08 2023-09-01 河北诚成肥业股份有限公司 一种化肥滚筒造粒用喷射装置
CN116672965B (zh) * 2023-06-08 2024-05-03 河北诚成肥业股份有限公司 一种化肥滚筒造粒用喷射装置

Also Published As

Publication number Publication date
FR2011252A1 (zh) 1970-02-27
NL6909405A (zh) 1969-12-23
GB1238541A (zh) 1971-07-07
DE1930464A1 (de) 1970-01-02
BE734700A (zh) 1969-12-01
ES368500A1 (es) 1971-07-01
CH497203A (de) 1970-10-15

Similar Documents

Publication Publication Date Title
US3614000A (en) Method for the comminution of particulate solid materials
US4538764A (en) Method and apparatus for providing finely divided powder
US4018388A (en) Jet-type axial pulverizer
KR850000521B1 (ko) 유체 에너지에 의한 미분 재료의 분쇄기
CA1213573A (en) Pulverizer
US4749133A (en) Apparatus for the pulverization and burning of solid fuels
US7673827B2 (en) Bowl mill for a coal pulverizer with an air mill for primary entry of air
CA1181052A (en) Gas flow type crushing and classifying apparatus
US4526324A (en) Jet-type grinding mill
US4504018A (en) Particle classifier apparatus and method with rudder control vane
US5976224A (en) Separating carbon from ash
CN106040393A (zh) 水射流粉碎系统
US1791100A (en) Reducing fluidizer and method of fluidizing
US2636688A (en) Method for treating coal and the like
US2515541A (en) Apparatus for disintegration of solids
US2735626A (en) trost
US4131239A (en) Fluid energy mill for large particulate materials
US7028847B2 (en) High efficiency two-stage dynamic classifier
US2602595A (en) Fluid impact pulverizer
US3508714A (en) Multiple section fluid energy grinding mill
EP0211117A2 (en) Method and apparatus for providing finely divided powder
US3467317A (en) Fluid energy grinding method and means
JPS641182B2 (zh)
JPH01215354A (ja) 粉砕およびコーティング装置
US3550868A (en) Fluid energy milling solid granular material