US3465971A - Deflector arrangement for use in a grinding mill - Google Patents

Deflector arrangement for use in a grinding mill Download PDF

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Publication number
US3465971A
US3465971A US605410A US3465971DA US3465971A US 3465971 A US3465971 A US 3465971A US 605410 A US605410 A US 605410A US 3465971D A US3465971D A US 3465971DA US 3465971 A US3465971 A US 3465971A
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United States
Prior art keywords
grinding
particles
mill
gas
pulverized
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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
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US605410A
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English (en)
Inventor
John F Dalenberg
Elmer H Todd
John W Carpenter
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Combustion Engineering Inc
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Combustion Engineering Inc
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Publication date
Application filed by Combustion Engineering Inc filed Critical Combustion Engineering Inc
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Publication of US3465971A publication Critical patent/US3465971A/en
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K7/00—Modulating pulses with a continuously-variable modulating signal
    • H03K7/08—Duration or width modulation ; Duty cycle modulation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C15/00—Disintegrating by milling members in the form of rollers or balls co-operating with rings or discs
    • B02C15/001—Air flow directing means positioned on the periphery of the horizontally rotating milling surface
    • 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
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K7/00—Modulating pulses with a continuously-variable modulating signal
    • H03K7/04—Position modulation, i.e. PPM
    • 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

  • This invention relates to an improvement in a rotary bowl mill adapted to grind and pulverize solid materials, and in particular to an improved deflector means for properly guiding the flow of gas and pulverized material within the mill.
  • FIGURE 1 is a sectional side view of a pulverizing bowl mill embodying our invention
  • FIGURE 2 is an enlarged plan view of the deflector means shown in FIGURE 1;
  • FIGURE 3 is a side view of the deflector means shown in FIGURE 2.
  • FIGURE 1 numeral denotes a bowl mill for grinding coal or other material therein. Inside the housing is positioned a rotatable bowl or table 12, mounted on shaft 14. Shaft 14 along with the attached bowl 12 is rotated by means of worm wheel 18, which engages worm 16 mounted on motor driven shaft 20.
  • a plurality of grinding elements or rollers 22 are rotatably mounted on shafts 24.
  • An adjustable spring 26 urges each roller 22 towards the upper surface of the grinding ring 12.
  • a material to be pulverized such as coal
  • a gas usually air, enters through opening 30, and flows through annular space 31 to convey the ground material passing over the lip of the bowl upwardly through the mill interior and 3,465,971 Patented Sept. 9, 1969 into the classifier 34.
  • the gas and coal enter the classifier by Way of inlets 32, which contain vane-s for directing the gas tangentially into the classifier.
  • the larger or more coarse particles of coal are separated out of the gas stream by centrifugal force, and fall back onto the grinding ring 12 through bottom opening 36 for further grinding.
  • the finer particles of coal are carried along with the gas stream and leave the mill through outlets 38.
  • each block-oif plate 42 Positioned in annular space 31 are a plurality of blockoff plates 42, there being one such blockoif plate for each roller 22.
  • Each block-oif plate 42 is positioned directly below its associated roller 22, and prevents pulverized coal from being carried upwardly into the area of the shafts the rollers are mounted on, which could impede their operation, and also could cause undue wear of these parts.
  • directing vanes 44 Positioned in the open annular spaces 31 adjacent to block-oif plates 42 are a plurality of directing vanes 44, which guide the gas and coal particles away from the plates 42, and into the space beneath the deflector means 40. These directing vanes 44 cause substantially all of the gas and coal particles to flow into the space beneath the deflector means 40.
  • the deflector means 40 has an upper triangular shaped portion 48, a streamlined portion 52, and a side portion 50.
  • Strut member 46 and angle iron 55 connect the deflector means 40 to the mill housing, and form the support for the deflector.
  • Streamlined portion 52 of the deflector 40 has a planar lower edge 54 which is slightly spaced from, and is parallel to, the upper surface of the grinding ring 12.
  • Coal to be pulverized enters the mill through inlet 28. After being pulverized between the upper surface of grinding ring 12 and rollers 22, the pulverized coal particles are thrown outwardly by centrifugal force into annular space 31. Gas flowing through directing vanes 44 in annular space 31, picks up the pulverized particles, and the gas-solid stream is guided by side wall 50 to the streamlined portion 52 and triangular portion 48 of the deflector means 40.
  • the gas-solid stream When the gas-solid stream reaches edge 54, it makes a sharp turn, and flows upwardly towards the classifier 34. As the gas-solid stream makes the sharp turn at edge 54, the finer solid particles, having little inertia, are carried along with it. The coarser or larger particles, having more inertia, tend to drop out of the gas stream at this point, back onto the grinding ring 12.
  • the remaining few oversize, heavy particles Will be separated out of the stream by centrifugal force in the classifier 34, and fall back onto grinding ring 12 by way of opening 36.
  • the fine particles will be carried along with the gas stream out of the mill through outlets 38.
  • Both the coarse particles separated out of the stream by deflectors 40, and the coarse particles separated out by classifier 34, will be fed beneath the grinding rolls 22 in a level, uniform manner by the overhanging edge 54 of the deflector means.
  • the coal particles carried thereby will be spread across the bowl by the edge 54 into a bed of material to be pulverized which is of uniform depth. This prevents uneven piling up of material against the rolls, which piling up increases the energy required to turn the rolls because of friction, and particle deformation to a size less than necessary and also reduces the grinding efficiency of such rolls.
  • the deflector means 40 by separating out a substantial portion of the heavy particles, will result in a number of advantages. It reduces the energy requirements of the mill while increasing its tributed along the length of the rolls by the overhanging edge of the deflector means.
  • a pulverizing mill comprising a closed casing, a grinding ring mounted within the casing for rotation about a central vertical axis, means for supporting and rotating the grinding ring, at least one grinding element mounted to coact with the grinding ring, means for introducing material to be pulverized onto the grinding ring, there being an annular gas passage between the grinding ring and the enclosing Wall of the casing, means for forcing gas upwardly through this annular passage to carry away pulverized particles in suspension, at least one of deflector means positioned above the annular passage, said deflector means being such in number and of such configuration that they direct a majority of the gas along with the pulverized particles both inwardly and downwardly, thus causing the more coarse pulverized particles to separate out of the gas stream and to be redeposited on the grinding ring.
  • a pulverizing mill comprising a closed casing, a grinding ring mounted within the casing for rotation about a central vertical axis, means for supporting and rotating the grinding ring at least one grinding roller mounted to coact with the grinding ring, means for introducing material to be pulverized onto the grinding ring, there being an annular gas passage between the grinding ring and the enclosing wall of the casing, means for forcing gas upwardly through this annular passage to carry away pulverized particles in suspension, at least one deflector means positioned above the annular passage, a plurality of guide vanes positioned so as to direct a majority of the gas along with the pulverized particles into the deflector means, each deflector means having a curved surface which is directed downwardly and inwardly towards the grinding ring, the edge of such surface being spaced from the grind ing ring, whereby the gas along with the pulverized particles entering the deflector means is directed inwardly and downwardly by the deflector means, thus causing the more coarse
  • each deflector means being positioned upstream of its associated grinding roller in the direction of rotation of the grinding ring, the edge of the curved surface of each deflector means is parallel to the upper surface of the grinding ring, and extends in a radial direction sufficient to cause the material being pulverized to be fed evenly throughout the length of each grinding roller.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Crushing And Grinding (AREA)
  • Amplitude Modulation (AREA)
  • Pulse Circuits (AREA)
US605410A 1966-12-28 1966-12-28 Deflector arrangement for use in a grinding mill Expired - Lifetime US3465971A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US60541066A 1966-12-28 1966-12-28

Publications (1)

Publication Number Publication Date
US3465971A true US3465971A (en) 1969-09-09

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Family Applications (1)

Application Number Title Priority Date Filing Date
US605410A Expired - Lifetime US3465971A (en) 1966-12-28 1966-12-28 Deflector arrangement for use in a grinding mill

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Country Link
US (1) US3465971A (US06605200-20030812-C00035.png)
BE (2) BE705087A (US06605200-20030812-C00035.png)
CH (1) CH484701A (US06605200-20030812-C00035.png)
ES (1) ES346000A1 (US06605200-20030812-C00035.png)
FR (1) FR929389A (US06605200-20030812-C00035.png)
GB (2) GB624543A (US06605200-20030812-C00035.png)
NL (2) NL6714390A (US06605200-20030812-C00035.png)

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4004740A (en) * 1975-01-28 1977-01-25 Polysius Ag Roller crushing mill
JPS5597258A (en) * 1979-01-19 1980-07-24 Kawasaki Heavy Ind Ltd Structure of stator of spiral vortex type pulverizer
JPS55107242U (US06605200-20030812-C00035.png) * 1979-01-19 1980-07-26
US4234132A (en) * 1979-05-21 1980-11-18 Combustion Engineering, Inc. Bowl mill with air deflector means
DE3633747A1 (de) * 1985-10-29 1987-05-07 Smidth & Co As F L Vertikale rollenmuehle
US4754932A (en) * 1987-03-18 1988-07-05 Combustion Engineering, Inc. Coal pulverizer inerting and fire extinguishing system
US4792099A (en) * 1987-04-29 1988-12-20 Combustion Engineering, Inc. Pulverizer auxiliary lubrication system
JPH0757324B2 (ja) 1987-03-24 1995-06-21 三菱重工業株式会社 回転式分級機付ローラミル
WO1999058246A1 (en) 1998-05-13 1999-11-18 Abb Alstom Power Inc. Control method and system for a coal mill in boilers
WO2000051740A1 (en) 1999-03-01 2000-09-08 Alstom Power Inc. An arrangement for securing a vane wheel assembly to a grinding table of a pulverizer bowl mill
US20060255195A1 (en) * 2005-05-13 2006-11-16 Alstom Technology Ltd High efficiency bowl mill
US7252253B2 (en) 2003-05-13 2007-08-07 Bharat Heavy Electricals Ltd. Bowl mill for a coal pulverizer with an air mill for primary entry of air
US20070257144A1 (en) * 2005-06-28 2007-11-08 Thomas Loesche Roller Mill Safety System
US20080054112A1 (en) * 2006-09-01 2008-03-06 Alstom Technology Ltd. Low profile primary classifier
US20080237379A1 (en) * 2007-03-29 2008-10-02 Alstom Technology Ltd. Seal for coiled spring assembly
US20090308961A1 (en) * 2008-06-13 2009-12-17 Alstom Technology Ltd. Electronically controlled journal loading system
US20100077616A1 (en) * 2008-09-26 2010-04-01 Alstom Technology Ltd. Method and apparatus for extended life journal assembly
US20100119187A1 (en) * 2008-11-11 2010-05-13 Babcock Power Services Inc. Bearing upgrade and kit

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3223286A (en) * 1961-08-16 1965-12-14 Gen Turbine Corp Portable sprayer with air operated mixing means
DE19806895C2 (de) * 1998-02-19 2002-10-24 Pfeiffer Ag Geb Verfahren und Vorrichtung zum Optimieren des Mahlbettes von Walzenschüsselmühlen

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2206145A (en) * 1938-12-22 1940-07-02 Comb Eng Co Inc Air flow choke for bowl mills
US2431746A (en) * 1944-08-25 1947-12-02 Comb Eng Co Inc Bowl mill with vane means providing uniform velocity upwardly swirling air currents
US2641387A (en) * 1947-02-27 1953-06-09 Simpson Herbert Corp Mixing machine discharge door
US2698142A (en) * 1953-02-03 1954-12-28 Combustion Eng Bowl mill with novel bowl and air flow directing means
US2818219A (en) * 1954-03-24 1957-12-31 Straight Engineering Co Dry pan scraper

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2206145A (en) * 1938-12-22 1940-07-02 Comb Eng Co Inc Air flow choke for bowl mills
US2431746A (en) * 1944-08-25 1947-12-02 Comb Eng Co Inc Bowl mill with vane means providing uniform velocity upwardly swirling air currents
US2641387A (en) * 1947-02-27 1953-06-09 Simpson Herbert Corp Mixing machine discharge door
US2698142A (en) * 1953-02-03 1954-12-28 Combustion Eng Bowl mill with novel bowl and air flow directing means
US2818219A (en) * 1954-03-24 1957-12-31 Straight Engineering Co Dry pan scraper

Cited By (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4004740A (en) * 1975-01-28 1977-01-25 Polysius Ag Roller crushing mill
JPS5813950Y2 (ja) * 1979-01-19 1983-03-18 川崎重工業株式会社 微粉砕装置
JPS5597258A (en) * 1979-01-19 1980-07-24 Kawasaki Heavy Ind Ltd Structure of stator of spiral vortex type pulverizer
JPS55107242U (US06605200-20030812-C00035.png) * 1979-01-19 1980-07-26
JPS5814822B2 (ja) * 1979-01-19 1983-03-22 川崎重工業株式会社 渦流式微粉砕機のステ−タ構造
US4234132A (en) * 1979-05-21 1980-11-18 Combustion Engineering, Inc. Bowl mill with air deflector means
EP0022152A1 (en) * 1979-05-21 1981-01-14 Combustion Engineering, Inc. Bowl mill with air deflector means
DE3633747A1 (de) * 1985-10-29 1987-05-07 Smidth & Co As F L Vertikale rollenmuehle
US4754932A (en) * 1987-03-18 1988-07-05 Combustion Engineering, Inc. Coal pulverizer inerting and fire extinguishing system
WO1988006920A1 (en) * 1987-03-18 1988-09-22 Combustion Engineering, Inc. Coal pulverizer inerting and fire extinguishing system
AU592287B2 (en) * 1987-03-18 1990-01-04 Combustion Engineering Inc. Coal pulverizer inerting and fire extinguishing system
JPH0757324B2 (ja) 1987-03-24 1995-06-21 三菱重工業株式会社 回転式分級機付ローラミル
US4792099A (en) * 1987-04-29 1988-12-20 Combustion Engineering, Inc. Pulverizer auxiliary lubrication system
WO1999058246A1 (en) 1998-05-13 1999-11-18 Abb Alstom Power Inc. Control method and system for a coal mill in boilers
WO2000051740A1 (en) 1999-03-01 2000-09-08 Alstom Power Inc. An arrangement for securing a vane wheel assembly to a grinding table of a pulverizer bowl mill
US7252253B2 (en) 2003-05-13 2007-08-07 Bharat Heavy Electricals Ltd. Bowl mill for a coal pulverizer with an air mill for primary entry of air
US20070290088A1 (en) * 2003-05-13 2007-12-20 Bharat Heavy Electricals Ltd. Bowl mill for a coal pulverizer with an air mill for primary entry of air
US7673827B2 (en) 2003-05-13 2010-03-09 Bharat Heavy Electricals, Ltd. Bowl mill for a coal pulverizer with an air mill for primary entry of air
US7267293B2 (en) 2005-05-13 2007-09-11 Alstom Technology Ltd High efficiency bowl mill
US20060255195A1 (en) * 2005-05-13 2006-11-16 Alstom Technology Ltd High efficiency bowl mill
US7731116B2 (en) * 2005-06-28 2010-06-08 Loesche Gmbh Roller mill safety system
US20070257144A1 (en) * 2005-06-28 2007-11-08 Thomas Loesche Roller Mill Safety System
US20080054112A1 (en) * 2006-09-01 2008-03-06 Alstom Technology Ltd. Low profile primary classifier
US7448565B2 (en) 2006-09-01 2008-11-11 Alstom Technology Ltd Low profile primary classifier
US20080237379A1 (en) * 2007-03-29 2008-10-02 Alstom Technology Ltd. Seal for coiled spring assembly
US7584917B2 (en) 2007-03-29 2009-09-08 Alstom Technology Ltd Seal for coiled spring assembly
US20090308961A1 (en) * 2008-06-13 2009-12-17 Alstom Technology Ltd. Electronically controlled journal loading system
US7690590B2 (en) 2008-06-13 2010-04-06 Alstom Technology Ltd Electronically controlled journal loading system
US20100077616A1 (en) * 2008-09-26 2010-04-01 Alstom Technology Ltd. Method and apparatus for extended life journal assembly
US8087172B2 (en) 2008-09-26 2012-01-03 Alstom Technology Ltd. Method and apparatus for extended life journal assembly
US20100119187A1 (en) * 2008-11-11 2010-05-13 Babcock Power Services Inc. Bearing upgrade and kit
US8491196B2 (en) 2008-11-11 2013-07-23 Babcock Power Services, Inc. Bearing upgrade and kit
US8622623B2 (en) 2008-11-11 2014-01-07 Babcock Power Services, Inc. Bearing upgrade and kit

Also Published As

Publication number Publication date
FR929389A (fr) 1947-12-24
NL132163C (US06605200-20030812-C00035.png)
ES346000A1 (es) 1969-01-16
NL6714390A (US06605200-20030812-C00035.png) 1968-07-01
BE705087A (US06605200-20030812-C00035.png) 1968-04-16
GB1189317A (en) 1970-04-22
GB624543A (en) 1949-06-10
BE475118A (US06605200-20030812-C00035.png)
CH484701A (de) 1970-01-31

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