US3529781A - Rotary grinding mill - Google Patents

Rotary grinding mill Download PDF

Info

Publication number
US3529781A
US3529781A US647152A US3529781DA US3529781A US 3529781 A US3529781 A US 3529781A US 647152 A US647152 A US 647152A US 3529781D A US3529781D A US 3529781DA US 3529781 A US3529781 A US 3529781A
Authority
US
United States
Prior art keywords
grinding
chamber
discharge chamber
mill
discharge
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
US647152A
Other languages
English (en)
Inventor
Niels E Hastrup
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.)
FLSmidth and Co AS
Original Assignee
FLSmidth and Co AS
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 FLSmidth and Co AS filed Critical FLSmidth and Co AS
Application granted granted Critical
Publication of US3529781A publication Critical patent/US3529781A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • B02C17/00—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
    • B02C17/18—Details
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C17/00—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
    • B02C17/04—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls with unperforated container
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C17/00—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
    • B02C17/04—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls with unperforated container
    • B02C17/06—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls with unperforated container with several compartments

Definitions

  • annularly protruding partitions commonly known as dam rings, have been used to retain the grinding bodies within the grinding chamber, but this technique alone has not proved successful.
  • This invention relates to a rotatable, generally cylindrical, grinding mill for grinding material with a grinding media and comprises a grinding chamber having a material inlet; a discharge chamber positioned immediately adjacent to and communicating with the grinding chamber, said discharge chamber having a discharge outlet; a partition separating these chambers; and means within the discharge chamber for continuously returning, through the partition, any grinding media, that is, grinding bodies, to the grinding chamber from the discharge chamber.
  • Preferred means for returning the grinding bodies to the grinding chamber consists of at least one tube running essentially spirally from the periphery of the discharge chamber to a point radially inwards of the imperforate annular part of the partition which separates the grinding chamber from the discharge chamber.
  • this novel arrangement provides for the continual return of the grinding bodies from the discharge chamber at substantially the same rate as they enter it. While it might be true that some of the grinding bodies may indeed be discharged with the ground material from the discharge chamber at the start of the operation, the grinding bodies will all be returned once the process is in regular operation.
  • FIG. 1 is a vertical central sectional view of the invention taken on line 1-1 of FIG. 2;
  • FIG. 2 is a sectional view taken along lines 22 of FIG. 1;
  • FIG. 3 is a sectional view taken along lines 33 of FIG. 1;
  • FIG. 4 is a partial vertical central sectional view of a first modification of the invention.
  • FIG. 5 is an end view partly in section taken along lines 5--5 of FIG. 4;
  • FIG. 6 is a partial vertical central sectional view of a second modification of the invention.
  • FIG. 7 is a sectional view taken along lines 66 of FIG. 6;
  • FIG. 8 is a partial vertical central sectional view of a third modification of the invention.
  • FIG. 9 is a sectional view taken along lines 99 of FIG. 8;
  • FIG. 10 is a partial vertical central sectional view of a fourth modification of the invention.
  • FIG. 11 is a partial vertical central sectional view of a fifth modification of the invention.
  • FIG. 12 is a vertical central view of a modification in the outlet end of another mill of the invention.
  • FIG. 13 is a section taken along the lines 13-13 of FIG. 12;
  • FIG. 14 is a section taken along the lines .1414 of FIG. 12, and
  • FIG. 15 is a section taken along the lines 1515 of FIG. 12.
  • the rotary grinding mill is generally indicated by 1 and comprises an outer casing 2 and end walls 3 and 4.
  • the mill casing 2 is divided into preferably a grinding chamber 5, a discharge chamber .6 and a distributing chamber 7.
  • the grinding chamber carries a material inlet 8 located in end wall 3.
  • the distributing chamber 7 is arranged immediately adjacent to the discharge chamber 6 with a partition plate 12 separating the respective chambers.
  • the other end of the distributing chamber 7 is closed by the end wall 4 of the mill 1.
  • the end wall 4 has a material outlet 13 extending therethrough.
  • a plurality of lifters 14 are mounted on the discharge chamber side of the annular ring partition. These lifters 14 extend radially inwardly from the inner surface of the discharge chamber 6.
  • the lifters 14 are adapted to lift the grinding bodies from the lower portion of the casing 2, where grinding bodies accumulate, to a point above the ground material in the discharge chamber 6 where, upon falling from the lifters 14, the grinding bodies tend to pass back through the aperture 11 in the annular ring partitions 10, due to the turbulence occurring within the discharge chamber 6.
  • the lifters 14 need not exactly extend radially inwardly from the inner surface of the discharge chamber 6, but may project within the discharge chamber 6 at any suitable angle, as long as the lifters 14 function to lift the grinding bodies within the discharge chamber 6 and allow the bodies to fall within the immediate vicinity of the aperture 11 of the annular ring partition 10. Still further, the lifters 14 may even be arcuate in shape and still accomplish the above purpose.
  • the partition plate 12 carries a central discharge material opening 16 and a plurality of material discharge arcuate slots 17 are positioned peripherally about the central opening 16. Located outwardly of each respective slot 17, an arced deflector 18 is mounted on the plate 12 to extend into the discharge chamber 6. Each deflector 18 is arranged so that it is concave in the direction towards its respective slot 17.
  • the distributing chamber 7 carries a plurality of scoops 20 positioned between the partition plate 12 and the end wall '4.
  • the scoops 20 are arcuate in shape and are arranged Within the distributing chamber in such a way that they are concave in the direction of the material outlet 13. These scoops 20 thereby easily distribute the ground material passing through the slots 17 in the partition plate 12 to the material outlet 13 in the end wall 4.
  • the mill casing 2 is suitably rotated on a rail 23 and roller assembly 24. Further, the conduit 21 is mounted with the bearing assembly 22 so that it may rotate along with the mill casing 2.
  • this grinding mill may be described as follows. A desired amount of unground material, along with grinding bodies, such as grinding balls, is introduced into the grinding chamber 5 through material inlet 8. The rotation of the grinding mill 5 is initiated by a suitable motor (not shown). The casing 2 is rotated in the direction indicated by the arrow A in FIGS. 2 and 3. The material, after being ground to a desired size, passes through aperture 11 in the annular ring partition 10 and spills into the discharge chamber .6. The annular partition 10 retains the great majority of the grinding bodies within the grinding chamber 5; however, due to the turbulence within the grinding chamber 5, some grinding bodies are carried through the aperture 11 in the annular ring partition, along with the ground material, and settle in the discharge chamber 6.
  • the ground material is discharged into the distributing chamber 7 from the discharge chamber 6 through the central discharge opening 16 and discharge slots -17 in the partition plate 12. The ground material is then distributed into the hollow discharge conduit 21 by the action of the scoops 20 in the distributing chamber 7.
  • the annular ring partition 10 retains a large majority of the grinding bodies within the grinding chamber 5.
  • the grinding bodies passing into the discharge chamber 6 are returned to the grinding chamber 5 at substantially the same rate as they enter the discharge chamber 6 by the action of the lifters 14 which lift the grinding bodies and allow them to fall within the discharge chamber. Due to the turbulence occurring from the speed of rotation of the mill 1, and due to the rebounding action of the grinding bodies, the grinding bodies falling from the lifters 14- tend to pass through the aperture 11 in the partition 10.
  • the deflectors 18 are mounted on the plate 12. These deflectors 18 divert any grinding bodies downwardly away from the central opening 16 and the slots 17 in the partition plate 12 so that the grinding bodies may more easily come into contact with the lifters 14.
  • FIGS. 4 and 5 The modification illustrated in FIGS. 4 and 5 is closely similar to that shown in FIGS. 1-3. However, in this modification, the central aperture 11 in the annular ring partition 10 is surrounded by a frusto-conical ring 25, the purpose of which is to restrict to some extent the passage of grinding bodies from the grinding chamber 5 to the discharge chamber 6.
  • the discharge chamber 6 is provided with a lining 26 which tapers towards the material outlet 13 in the end wall 4 of the mill 1.
  • the lining 26 may be made of any suitable material but must be of a shape such that it forms a frusto-conical discharge chamber having a diameter decreasing in the direction of the end wall 4 of the mill 1.
  • the lining not only causes the grinding bodies present in the discharge chamber 6 to move towards the annular ring partition 10, but also provides a discharge chamber 6 which may have a somewhat lower internal per pheral speed near the material outlet 13 than that tacthrdeved near the ring partition 10 when the mill is ro- Secondly, a circular deflector plate 27 is suspended vertically within the center of the discharge chamber 6 facing the aperture 11 of the ring partition 10. The de flector plate 27 is supported by supporting rods 28 which are anchored to the end wall 4 of the mill 1. The deflector plate 27 forms an annular passage for material between the discharge chamber lining 26 and the edge of the deflector plate 27.
  • the hollow discharge condurt 21 is provided with a rotating screw 30 having a central opening 31.
  • the screw is rotated in the direction of the discharge chamber 6 and, therefore, conveys any grinding bodies back into the discharge chamber 6 if some should, by chance, find their way into the hollow discharge conduit 21. Since the screw has a central opening, its rotation in the direction of the discharge chamber 6 does not prevent the movement of the ground material through the hollow conduit 21 since the ground material easily passes through the screw opening 31.
  • the mill shown in FIGS. 6 and 7 differs from that shown in FIGS. 4 and only in that the frusto-conical ring 25, positioned about the central aperture 11 of the annular ring partition 10, is replaced by a ring 32 of triangular cross-section, and in that the deflector plate 27 carries a frusto-conical extrusion 33 extending outwardly from the deflector plate 27 towards the aperture 11 in the annular ring partition Both ofthese features have been found to increase the tendency of the grinding bodies to return to the grinding chamber 6.
  • the mill shown in FIGS. 8 and 9 has three discharge chambers, 34, 35 and 36, positioned adjacent the grinding chamber 5. Each discharge chamber is separated by annular partitions 37, 38 and 39, all carrying frusto-conical rings 25 about their apertures 11, similar to those illustrated in FIG. 4.
  • scoops 20 are arranged for lifting ground material and distributing it to a screw 40 which has a short shaft of substantial diameter.
  • the screw 40 is rotated such that its threads 41 convey the ground material away from distributing chamber 7 and into the hollow conduit 21 which itself is devoid of any threads.
  • the end of the screw 40, facing the annular partition 39, is frusto-conical in shape to facilitate the return of the grinding bodies from the discharge chamber 36 to discharge chamber 35.
  • the mill shown in FIG. 10 resembles that shown in FIGS. 8 and 9 very closely, except that the diameter of each aperture 11 in each annular partition increases successively in the direction of the screw 40.
  • FIG. 11 illustrates a grinding mill similar to that shown in FIG. 10.
  • this grinding mill carries an annular lining 42 arranged about the internal periphery of the last discharge chamber 36.
  • This lining 42 thereby provides the discharge chamber 36 with an internal diameter smaller than the internal diameter of the preceding discharge chambers 34 and 35.
  • the reduced diameter enables the discharge chamber 36 to have an internal peripheral speed less than that obtainable in discharge chambers 34 and 35 when the mill is rotated; accordingly, the tendency of the grinding bodies to leave the discharge chamber through the arced slots 17 is reduced.
  • FIGS. 12-15 show another preferred means for returning the grinding bodies from the discharge chamber to the preceding grinding chamber.
  • this mill there is a darn ring 10 with a frusto-conical ring 25, the ground material and grinding bodies passing through the dam ring 10 into a discharge chamber 6 as before.
  • this discharge chamber there are two essentially spiral tubes 43 and 44, each having a mouth 45 lying at the periphery of the discharge chamber 6 and arranged to move through the mass of grinding bodies that at any instant is on the bottom of the discharge chamber.
  • the mill continues to rotate some of these grinding bodies pass through the mouth 45 of the tube and move along the tube until they reach its other end 46, which is curved as shown in FIG. 12, to enter the central opening in the dam ring.
  • a rotatable grinding mill for grinding material with grinding media comprising a cylindrical grinding chamber having a material inlet, an aligned cylindrical discharge chamber positioned immediately adjacent thereto and having an axial discharge outlet for the overflow discharge of the ground product, a disc-like partition disposed normal to the axis of said cylindrical chambers between the said chambers and having a central circular aperture, the ground material including a small portion of the grinding media flowing through said aperture from the grinding chamber into the discharge chamber, and means within the discharge chamber for returning said grinding media through said aperture to the grinding chamber.
  • said means for returning grinding media to the grinding chamber comprises at least one tube running essentially spirally from the periphery of the discharge chamber to a point radially inward of the disc-like partition.
  • the grinding mill according to claim 2 having two essentially spiral tubes having their mouths located apart.
  • each deflector is concave in the direction of each respective slot.
  • the grinding mill according to claim 5 including a discharge conduit and a distributing chamber disposed adjacent the discharge chamber for routing the ground material emanating from the discharge chamber to the discharge conduit.
  • a discharge conduit communicates with the discharge outlet having a central opening extending therethrough, and a screw is fixed to the surface of the discharge conduit for conveying grinding media back into the discharge chamber while allowing the ground material to pass through the screw opening.

Landscapes

  • Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Crushing And Grinding (AREA)
US647152A 1966-06-23 1967-06-19 Rotary grinding mill Expired - Lifetime US3529781A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB28084/66A GB1129188A (en) 1966-06-23 1966-06-23 Grinding process and mill for carrying out the process

Publications (1)

Publication Number Publication Date
US3529781A true US3529781A (en) 1970-09-22

Family

ID=10270023

Family Applications (1)

Application Number Title Priority Date Filing Date
US647152A Expired - Lifetime US3529781A (en) 1966-06-23 1967-06-19 Rotary grinding mill

Country Status (10)

Country Link
US (1) US3529781A (enrdf_load_stackoverflow)
JP (1) JPS5123738B1 (enrdf_load_stackoverflow)
AT (1) AT295978B (enrdf_load_stackoverflow)
BE (1) BE700284A (enrdf_load_stackoverflow)
CH (1) CH472240A (enrdf_load_stackoverflow)
DE (1) DE1607591C3 (enrdf_load_stackoverflow)
ES (2) ES342181A1 (enrdf_load_stackoverflow)
GB (1) GB1129188A (enrdf_load_stackoverflow)
NL (1) NL6708827A (enrdf_load_stackoverflow)
SE (1) SE339384B (enrdf_load_stackoverflow)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3677479A (en) * 1969-07-31 1972-07-18 Pierre Arsene Slegten Automatic grading linings for cylindrical tube or similar mills
US3869091A (en) * 1972-05-10 1975-03-04 Smidth & Co As F L Tube mill
US4369926A (en) * 1978-12-29 1983-01-25 F. L. Smidth & Co. Method and apparatus for grinding granular materials
WO1994019105A1 (en) * 1993-02-03 1994-09-01 Aktsionernoe Obschestvo Kamaz Binding suspension, a process and device for obtaining the same, and the use of the said binding suspension in a coating to prevent metal penetration, in a compound for cleaning sanitary equipment and in a mixture for producing building materials
US20110139913A1 (en) * 2009-12-11 2011-06-16 Flsmidth A/S Milling device
CN102974432A (zh) * 2012-12-26 2013-03-20 广州派勒机械设备有限公司 一种动态分离出料式研磨机

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5417425U (enrdf_load_stackoverflow) * 1977-07-07 1979-02-03
DE102007043670A1 (de) 2007-09-13 2009-04-02 Netzsch-Feinmahltechnik Gmbh Rührwerkskugelmühle

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1368739A (en) * 1919-05-15 1921-02-15 Smidth & Co As F L Ball-grinding mill
US1520537A (en) * 1923-03-16 1924-12-23 Markus Louis De Method and apparatus for pulverizing
US1630992A (en) * 1924-11-25 1927-05-31 Harry H Waterman Air-swept ball mill
US1649813A (en) * 1925-08-14 1927-11-22 Smidth & Co As F L Grinding cement material, etc.
US1712082A (en) * 1921-08-11 1929-05-07 Koppers Heinrich Process and apparatus for distilling solid carbonaceous material
US2332701A (en) * 1940-06-12 1943-10-26 Charles W Dowsett System and method of grinding
DE1055927B (de) * 1954-05-06 1959-04-23 Camillo Bargero Trommelmuehle
US2885155A (en) * 1955-06-22 1959-05-05 Smidth & Co As F L Grinding mills with classifying linings
US3144212A (en) * 1961-10-31 1964-08-11 Allis Chalmers Mfg Co Combination rod and ball grinding mill
US3298618A (en) * 1963-10-17 1967-01-17 Du Pont Dispersing apparatus

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE565994C (de) * 1931-02-17 1932-12-09 Willi Schmidt Trommel-, Rohr- oder Verbundmuehle mit Absaugung des fein gemahlenen Gutes

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1368739A (en) * 1919-05-15 1921-02-15 Smidth & Co As F L Ball-grinding mill
US1712082A (en) * 1921-08-11 1929-05-07 Koppers Heinrich Process and apparatus for distilling solid carbonaceous material
US1520537A (en) * 1923-03-16 1924-12-23 Markus Louis De Method and apparatus for pulverizing
US1630992A (en) * 1924-11-25 1927-05-31 Harry H Waterman Air-swept ball mill
US1649813A (en) * 1925-08-14 1927-11-22 Smidth & Co As F L Grinding cement material, etc.
US2332701A (en) * 1940-06-12 1943-10-26 Charles W Dowsett System and method of grinding
DE1055927B (de) * 1954-05-06 1959-04-23 Camillo Bargero Trommelmuehle
US2885155A (en) * 1955-06-22 1959-05-05 Smidth & Co As F L Grinding mills with classifying linings
US3144212A (en) * 1961-10-31 1964-08-11 Allis Chalmers Mfg Co Combination rod and ball grinding mill
US3298618A (en) * 1963-10-17 1967-01-17 Du Pont Dispersing apparatus

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3677479A (en) * 1969-07-31 1972-07-18 Pierre Arsene Slegten Automatic grading linings for cylindrical tube or similar mills
US3869091A (en) * 1972-05-10 1975-03-04 Smidth & Co As F L Tube mill
US4369926A (en) * 1978-12-29 1983-01-25 F. L. Smidth & Co. Method and apparatus for grinding granular materials
WO1994019105A1 (en) * 1993-02-03 1994-09-01 Aktsionernoe Obschestvo Kamaz Binding suspension, a process and device for obtaining the same, and the use of the said binding suspension in a coating to prevent metal penetration, in a compound for cleaning sanitary equipment and in a mixture for producing building materials
US20110139913A1 (en) * 2009-12-11 2011-06-16 Flsmidth A/S Milling device
US8091817B2 (en) 2009-12-11 2012-01-10 Flsmidth A/S Milling device
CN102974432A (zh) * 2012-12-26 2013-03-20 广州派勒机械设备有限公司 一种动态分离出料式研磨机
CN102974432B (zh) * 2012-12-26 2015-12-02 广州派勒机械设备有限公司 一种动态分离出料式研磨机

Also Published As

Publication number Publication date
GB1129188A (en) 1968-10-02
ES342181A1 (es) 1968-10-01
JPS5123738B1 (enrdf_load_stackoverflow) 1976-07-19
ES353746A1 (es) 1969-10-16
DE1607591B2 (de) 1980-05-22
DE1607591A1 (de) 1969-10-02
AT295978B (de) 1971-12-15
SE339384B (enrdf_load_stackoverflow) 1971-10-04
BE700284A (enrdf_load_stackoverflow) 1967-12-21
DE1607591C3 (de) 1981-03-26
CH472240A (fr) 1969-05-15
NL6708827A (enrdf_load_stackoverflow) 1967-12-27

Similar Documents

Publication Publication Date Title
US4694994A (en) Roller mill
US1664769A (en) Method and apparatus for centrifugal thickening of mixtures and clarifying of liquids
US3898157A (en) Two stage pressure pulp screen device with stationary cylindrical screen
US3964717A (en) Tube mill
US3529781A (en) Rotary grinding mill
US2312829A (en) Method and apparatus for separating liquids from solids
US2724549A (en) Centrifugal separator and method of operating the same
GB994280A (en) Grinding mill and process of grinding
US3831764A (en) Pusher-type centrifuge
US3423015A (en) Continuous centrifugal separator with pool depth control
US2753996A (en) Flow separators
US2368876A (en) Continuous centrifugal separator
JPH05504998A (ja) パルスなしスクリーン
US2802574A (en) Centrifugal machine for extracting solids from liquids
US2004468A (en) Centrifugal separator
US2698142A (en) Bowl mill with novel bowl and air flow directing means
US3899417A (en) In-line pressure sifter
US1834094A (en) Pulverizer and separator
US3459380A (en) Apparatus and method for making a slurry
US5055182A (en) Separator
US1974651A (en) Pulp screening machine
US2185960A (en) Mill
US3877650A (en) Partition for tumbling mills or the like
US3275140A (en) Air separator with fluidized discharge
US3149067A (en) Screening device