EP0211117A2 - Procédé et appareil pour la production de poudre finement divisée - Google Patents

Procédé et appareil pour la production de poudre finement divisée Download PDF

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Publication number
EP0211117A2
EP0211117A2 EP85305506A EP85305506A EP0211117A2 EP 0211117 A2 EP0211117 A2 EP 0211117A2 EP 85305506 A EP85305506 A EP 85305506A EP 85305506 A EP85305506 A EP 85305506A EP 0211117 A2 EP0211117 A2 EP 0211117A2
Authority
EP
European Patent Office
Prior art keywords
fluid
particles
chamber
vortex
classifier
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.)
Withdrawn
Application number
EP85305506A
Other languages
German (de)
English (en)
Other versions
EP0211117A3 (fr
Inventor
Richard M Dunbar
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.)
RMD Industries Inc
Original Assignee
RMD Industries Inc
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
Priority to US06/510,089 priority Critical patent/US4538764A/en
Application filed by RMD Industries Inc filed Critical RMD Industries Inc
Priority to EP85305506A priority patent/EP0211117A3/fr
Publication of EP0211117A2 publication Critical patent/EP0211117A2/fr
Publication of EP0211117A3 publication Critical patent/EP0211117A3/fr
Withdrawn legal-status Critical Current

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Classifications

    • 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
    • B02C19/065—Jet mills of the opposed-jet type

Definitions

  • the present invention relates to methods and apparatus for pulverizing and for the provision of material in finely divided form. More particularly, the present invention relates to a method and apparatus for pulverizing coal and to coordinate the coal grinding with furnace demand for fuel.
  • Coal owing to the content of pyrites and other abrasive impurities has always been difficult to grind, especially to particle sizes in the ten micron (ultrafine) range.
  • the power industry has recognized that it has been advantageous to produce ultrafine coal so as to improve the coal's efficiency as a fuel. Coal would burn more completely, yield more heat and produce more manageable ash.
  • the power industry has always sought a practical and effective attrition mill, rather than one in which coal is broken by moving parts which are subject to rapid and severe wear. Such attrition mills would ideally break the coal by a process, comminution, which means to rub, grind or thrash to pieces.
  • the present invention relates to a method and apparatus for obtaining powders having a fineness which can be utilized in different industries.
  • the present invention has enabled the provision of a large number of materials in the form of powders much finer than could be produced by previous commercial apparatuses and procedures, and has made possible an extraordinarily efficient production of fine powders.
  • many materials hereinbefore considered difficult or impossible of commercial production in the form of fine powders can be readily produced in finely powdered form by means of the invention.
  • the invention contemplates the effectuation of pulverization by the use of fluid pressure in a highly efficient manner so that the material may be classified in a thorough and efficient manner.
  • a procedure and means whereby both a highly efficient pulverization and a highly efficient classification is obtained.
  • the present invention is adaptable to achieve efficient pulverization of many different types of materials, including, for example, ore which contains precious metals. In this manner, the extraction of such metals (such as gold fines) from raw ore deposits becomes much more efficient and cost effective.
  • the present invention provides means for grinding particles such a graphite, talc, chalk and other soft substances, especially coal, by colliding particles against each other.
  • particles such as graphite, talc, chalk and other soft substances, especially coal
  • at least two high-pressure opposed jets of fluid-borne particles are fired at each other, creating millions of collisions which break the particles in the process of attrition or comminution.
  • the fluid stream carries the particles to a classifier which sorts and removes the desired fraction for use and returns the rest for regrinding.
  • An object of the invention is the provision of a method and apparatus whereby a wide variety of solid materials may be readily provided in the form of a fine powder.
  • Another object is the provision of improved method and means for continuously breaking up particles of material.
  • coal having a maximum or average particle size which is about ten microns, may be readily obtained in quantity for use as a fuel source.
  • the apparatus of the present invention includes a classifier in the form of a cyclone which forms a gaseous vortex so as to separate particulates by driving coarser particles outwardly.
  • the operation of the classifier is adjustable so that, if desired, the system can be made compatible with the operating facilities of a power plant or other large fuel users. It is preferably designed so that either boiler or furnace controls can govern the rate of feed of coal required. Therefore, the present invention contemplates that in power plants, coal grinding is coordinated with furnace demand for fuel. When furnace demand increases, the system tolerates a brief burst of coarse mix so that constant fuel flow continues and no loss of furnace flame occurs. When furnace demand drops, the pulverizing means recirculates coal to produce a finer grind and avoids fuel overload at the furnace. Means may be also additionally provided to unload coal from the pulverizing means for safe storage if the furnace shuts down.
  • means for signalling interlocks which prevent any malfunction and, additionally, means for signalling maintenance.
  • an apparatus and method of providing materials in finely divided form which includes the steps of:
  • the speed of the vortex is higher than the speed of the first fluid stream and there is included means for controlling the velocity of the second gas stream.
  • the fluid and fine particles are withdrawn from the first zone upwardly through an outlet and to a storage area (or power plant as a fuel source) and the entrained coarse particles are moved downwardly into the second zone for regrinding.
  • FIGS. 1-3 there are utilized certain combinations or subcombinations of steps under various conditions whereby one or more of the highly advantageous results sought may be readily obtained.
  • the feed powder which may comprise some ore or chalk, talc, coal and the like is placed into a feed stock reservoir 10 and passed through line 11 by a known means, such as a helical screw 12, into line 13 wherein gaseous fluid carries the powder into classifying means 15.
  • the classifying means sorts the powder particles, removing the particles of a desired size, such as coal for use as a fuel, and returns the other coarse particles into a stream for grinding.
  • the powders enter a comminution of pulverization zone 20 by means of feed lines 20A and 20B.
  • the pulverization zone comprises a chamber 19 having a pair of opposing nozzles 21A and 21B wherein the feed from lines 20A and 20B are introduced together with streams of high-speed gaseous fluid from lines 22A and 22B so as to impinge upon each other.
  • the fluid streams are introduced into the pulverization zone 20 at such a high velocity as to exert a breaking or tearing effect on the particles as they impinge on other particles (or upon the walls of the pulverization zone 20). Also, because of the high relative movement of the fluid, undesirably large particles are thrown or bounced into, or otherwise reach the inner portion of the zone 20.
  • Two or more streams of gaseous fluid makes it possible for a large number of particles to keep moving in a variety of different directions so as to impinge upon each other at a high speed and with great breaking or tearing effect.
  • the gaseous fluid which is introduced into the pulverization zone 20 by means of nozzles 21A and 21B from lines 20A and 20B carries entrained particles out of the pulverization zone through outlet 23 into the feed line 13.
  • the high velocity movement is maintained as a result of the high energy being introduced from lines 22A and 22B.
  • the fluid and particles are combined with fresh feed stock and enter the classifier 15 for removal of desired particles and recycling of larger particles for further pulverization.
  • Material may be supplied substantially continuously during continued operation but a certain amount of pulsation in the feed will ordinarily not be harmful so long as the supply at any time is not sufficiently great, and so long as the intervals between the intermittent supply of materials are not sufficiently large so that substantial variations in the circulating load will occur.
  • the velocity of the introduced streams may vary considerably but should be of a high order. Such velocities are ordinarily obtained by applying high-pressure fluid to the nozzles to release a gaseous fluid, for instance, as steam or air, or inert gases through the jet opening of the nozzle.
  • a gaseous fluid for instance, as steam or air, or inert gases
  • the classifying means 15 comprises a mechanical cyclone having a cyclone tube 30, an inlet 31, an outlet 32, a secondary gas flow inlet 33, a gas nozzle 34, and a hub 35.
  • gas-conveyed particulates enter the cyclone tube axially or tangentially through inlet 31.
  • a secondary gas from an independent source enters the gas nozzle 34 and acts to provide a large number of essentially tangential fluid jets for the purposes of inducing a constant, controlled vortex in the cyclone tube.
  • particulates are acted upon by an outwardly directed centrifugal force which separates the particles according to aerodynamic diameter.
  • the separated solids having the larger aerodynamic diameters are carried downward while the finer particles which are insufficiently affected by the vortex flow reverse direction in the lower part of the cyclone tube and exit through outlet 32.
  • the present classifier provides significantly greater fine particle separation efficiency at high continuous throughputs. This high efficiency is maintained over a wide range of primary gas flows and solid loadings. It can be seen that controlling the flow of secondary gas also controls the speed of rotation of separation vortex, largely independently of the primary gas flow.
  • the pressure drop in the system is controlled by the secondary flow which is also an effective disperser.
  • Use of the classifier of the present invention has been found to produce a high efficiency over a wide range of primary gas flows and solids loadings without the problems of plugging.
  • a critical feature in the classifier of the present invention is the secondary gas nozzle assembly which imposes a vortex on the primary gas flow. This gas jet action separates particulates from the gas stream and prevents solids build-up on tube surfaces and eliminates system plugging.
  • one or more classifiers may be utilized with a common inlet and outlet and discharging of the collected solids into one or more closed hoppers.
  • the secondary gas range is preferably 15-20% of the primary air flow at 3-7 psig or 7-10% at 15 psig.
  • the material In the inner zone of the vortex, the material is classified by the centrifugal action of the vortex and all particles greater than a desired size (which may be exceedingly small) are returned to the outer zone by the centrifugal action.
  • the classification of material in this zone results in only the smallest particles being carried over with the fluid through the outlet.
  • an exceedingly effective classification is secured since the high-speed rotation of the vortex continues as the vortex spirals inwardly toward the outlet opening and there is no possibility for batches of the material to build-up or otherwise work back so as to ultimately overload the vortex and interfere with the classifying action.
  • Air, steam or any other suitable gaseous fluids may be utilized as the secondary gas, which may be at any desired temperature.
  • the secondary gas stream or streams is the same as the primary gaseous fluid.

Landscapes

  • Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Disintegrating Or Milling (AREA)
  • Combined Means For Separation Of Solids (AREA)
EP85305506A 1983-06-30 1985-08-02 Procédé et appareil pour la production de poudre finement divisée Withdrawn EP0211117A3 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US06/510,089 US4538764A (en) 1983-06-30 1983-06-30 Method and apparatus for providing finely divided powder
EP85305506A EP0211117A3 (fr) 1985-08-02 1985-08-02 Procédé et appareil pour la production de poudre finement divisée

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP85305506A EP0211117A3 (fr) 1985-08-02 1985-08-02 Procédé et appareil pour la production de poudre finement divisée

Publications (2)

Publication Number Publication Date
EP0211117A2 true EP0211117A2 (fr) 1987-02-25
EP0211117A3 EP0211117A3 (fr) 1988-02-03

Family

ID=8194308

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85305506A Withdrawn EP0211117A3 (fr) 1983-06-30 1985-08-02 Procédé et appareil pour la production de poudre finement divisée

Country Status (1)

Country Link
EP (1) EP0211117A3 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4431534A1 (de) * 1994-02-10 1995-08-17 Nied Roland Maschine zum Einwirken auf zermahl- und klassierbares Gut
DE3943733C2 (de) * 1989-05-12 1999-01-21 Canon Kk Vorrichtung und Verfahren zur Zerkleinerung und Klassierung von Pulver in Feinpulver
WO2007131502A1 (fr) * 2006-05-17 2007-11-22 Netzsch-Condux Mahltechnik Gmbh Procédé de production de très fines particules au moyen d'un broyeur à jet fluide
WO2009048592A1 (fr) 2007-10-09 2009-04-16 Cbp Carbon Industries, Inc. Dispositif pour classifier des particules dans un résidu charbonneux pyrolysé
US8177149B2 (en) 2006-04-13 2012-05-15 Roland Nied Method for the production of very fine particles by means of a jet mill
US8394189B2 (en) 2007-11-07 2013-03-12 John H. Fader Asphalt composition using pyrolysed carbonaceous material

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2624516A (en) * 1949-01-04 1953-01-06 Blaw Knox Co Fluid impact pulverizer and separator
US2636688A (en) * 1948-02-20 1953-04-28 Inst Gas Technology Method for treating coal and the like
US3186648A (en) * 1963-05-27 1965-06-01 Grace W R & Co Fluid energy mill
US3885931A (en) * 1972-06-12 1975-05-27 Donaldson Co Inc Vortex forming apparatus and method
US4019688A (en) * 1975-06-02 1977-04-26 Viktor Ivanovich Akunov Device for treating loose materials
US4538764A (en) * 1983-06-30 1985-09-03 Dunbar Richard M Method and apparatus for providing finely divided powder

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2636688A (en) * 1948-02-20 1953-04-28 Inst Gas Technology Method for treating coal and the like
US2624516A (en) * 1949-01-04 1953-01-06 Blaw Knox Co Fluid impact pulverizer and separator
US3186648A (en) * 1963-05-27 1965-06-01 Grace W R & Co Fluid energy mill
US3885931A (en) * 1972-06-12 1975-05-27 Donaldson Co Inc Vortex forming apparatus and method
US4019688A (en) * 1975-06-02 1977-04-26 Viktor Ivanovich Akunov Device for treating loose materials
US4538764A (en) * 1983-06-30 1985-09-03 Dunbar Richard M Method and apparatus for providing finely divided powder

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3943733C2 (de) * 1989-05-12 1999-01-21 Canon Kk Vorrichtung und Verfahren zur Zerkleinerung und Klassierung von Pulver in Feinpulver
DE4431534A1 (de) * 1994-02-10 1995-08-17 Nied Roland Maschine zum Einwirken auf zermahl- und klassierbares Gut
DE4431534B4 (de) * 1994-02-10 2006-12-28 Nied, Roland, Dr. Ing. Maschine zur Einwirkung auf zerkleinerbares und klassierbares Rohgut, sowie Verfahren zum Betrieb der Maschine
US8177149B2 (en) 2006-04-13 2012-05-15 Roland Nied Method for the production of very fine particles by means of a jet mill
WO2007131502A1 (fr) * 2006-05-17 2007-11-22 Netzsch-Condux Mahltechnik Gmbh Procédé de production de très fines particules au moyen d'un broyeur à jet fluide
US8047458B2 (en) 2006-05-17 2011-11-01 Roland Nied Method for producing very fine particles by means of a jet mill
CN101437621B (zh) * 2006-05-17 2014-06-11 罗兰·尼德 采用一种喷射式碾磨机生产极细粉粒的方法
WO2009048592A1 (fr) 2007-10-09 2009-04-16 Cbp Carbon Industries, Inc. Dispositif pour classifier des particules dans un résidu charbonneux pyrolysé
US8247527B2 (en) 2007-10-09 2012-08-21 Cbp Carbon Industries, Inc. Enhanced fine agglomerate mixture
US8322642B2 (en) 2007-10-09 2012-12-04 Fader John H Arrangement for classifying particles in a pyrolysed char
US8394189B2 (en) 2007-11-07 2013-03-12 John H. Fader Asphalt composition using pyrolysed carbonaceous material

Also Published As

Publication number Publication date
EP0211117A3 (fr) 1988-02-03

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