US3586248A - Process for grinding and sifting - Google Patents

Process for grinding and sifting Download PDF

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Publication number
US3586248A
US3586248A US805752A US3586248DA US3586248A US 3586248 A US3586248 A US 3586248A US 805752 A US805752 A US 805752A US 3586248D A US3586248D A US 3586248DA US 3586248 A US3586248 A US 3586248A
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US
United States
Prior art keywords
stream
material stream
sifter
sifting
fineness
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
US805752A
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English (en)
Inventor
Rudolf Ruegg
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.)
Sulzer Escher Wyss AG
Original Assignee
Escher Wyss AG
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Filing date
Publication date
Priority claimed from CH421168A external-priority patent/CH480093A/de
Application filed by Escher Wyss AG filed Critical Escher Wyss AG
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Publication of US3586248A publication Critical patent/US3586248A/en
Anticipated expiration legal-status Critical
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    • 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
    • B02C17/183—Feeding or discharging devices
    • B02C17/1835—Discharging devices combined with sorting or separating of material
    • B02C17/184—Discharging devices combined with sorting or separating of material with separator arranged in discharge path of crushing zone
    • B02C17/1845—Discharging devices combined with sorting or separating of material with separator arranged in discharge path of crushing zone with return of oversize material to crushing zone

Definitions

  • a process for grinding and sifting a granular material, more particularly cement comprises grinding the charge material stream and thereupon sifting the ground material stream and dividing the latter into a coarse material stream and a fine material stream, and said course material stream into said charge material stream, a closed circuit of coarse material thus being formed, and said fine material stream forming the finished product.
  • a partial stream is taken from said fine material stream and is reintroduced into said closed circuit.
  • the invention relates to a process by means of which fine regulation of the finished product may be effected in the simplest manner in plants which are operated for the production of a finished product of the fineness for which they are designed, and by means of which process it is furthermore possible to operate a plant also for the manufacture of a finished product of greater fineness than that for which it has been designed, and in which the changeover for this purpose may be effected rapidly and in the simplest manner.
  • a process of the hereinbefore described kind is carried out according to the invention in that a partial stream is taken from the fine material stream, and is introduced into the closed circuit.
  • FIGS. 1 to 4 show four such different plants
  • FIG. 5 shows an axial section through the top part of a particular design ofa sifter as contained in the FIGS. 1 to 4, and
  • FIG. 6 shows a portion ofa section on the line Vl-VI of FIG. 5, corresponding parts having the same reference in all figures.
  • FIGS. 1 to 4 DESCRIPTION OF PREFERRED EMBODIMENTS
  • a mill 1 and a sifter 2 From the sifter 2, a coarse material conduit 3 leads to the mill inlet 4, in which a raw material conduit 5 also opens.
  • a bucket elevator 6 connects the mill outlet 7 to the inlet of the sifter 2.
  • the fine material conduit 8 opens into a continuously adjustable switch 9.
  • a finished material conduit 10 leads to the outside of the plant from one outlet side of the switch 9.
  • a partial stream conduit 11 leads from the other outlet side of the switch 9 to the base of the bucket elevator 6.
  • any partial stream may be taken from the fine material stream coming from the shifter 2, and may be introduced into the closed circuit of the mill 1 directly in front of the sifter inlet, hence into the stream of material to be sifted, i.e., the ground material stream coming from the mill.
  • the fineness of the material to be sifted is increased, whereby an increase in the fineness of the fine material or finished material is brought about.
  • the devices necessary for this purpose are extremely simple and cheap, and operation of the regulation is extremely time-saving and simple.
  • the plant shown in FIG. 2 differs from that shown in FIG. I merely in that the partial stream conduit 12 does not lead to the base of the bucket elevator 6, but to the base of a second bucket elevator 66 conveying only the material of the partial stream to the sifter inlet.
  • This modification is suitable above all for plants which are subsequently modified for carrying out the process according to the invention, and in which the branched partial stream is so large that the original bucket elevator 6 is unable to convey the additional quantity of material. It may, however, also be advantageous where the maximum partial stream is so large that stoppage of the bucket elevator 66, when the entire fine material stream is discharged through the finished product conduit 10, results in an important saving power.
  • the partial stream conduit 13 does not lead to the base of the bucket elevator 6, like the partial stream conduit 11 in FIG. 1, but to the mill inlet 4.
  • a partial stream of the fine material stream coming from the sifter 2 may be introduced into the charge material stream composed of the raw material stream and the coarse material stream.
  • the partial stream is introduced into the closed circuit of the mill immediately in front of the mill 1.
  • This modification has the advantage that part of the fine material coming from the sifter 2 is again subjected to a grinding process. This is of advantage when an inadmissibly large quantity of oversize particles is present in the fine material. It still has, however, the disadvantage that the fine material returned to the grinding process eventually produces unwanted agglomeration and a buffer effect in the mill.
  • the plant according to FIG. 4 combines the advantages of the plants according to FIGS. 1 and 3 and obviates their disadvantages to a considerable extent. In it, the elements of both plants are combined.
  • the switch 9 is followed on the finished material side by a second switch 99, from which branches off not only the finished material conduit 10, but also the partial stream conduit 11 leading to the base of the bucket elevator 6, while the partial stream conduit 13, leading to the mill inlet 4, branches off the switch 9 as in FIG. 3.
  • This plant makes it possible to introduce into the closed circuit of the mill a partial stream directly in front of the mill 1 and directly in front of the sifter 2, respectively, according to the quality of the fine material leaving the sifter.
  • the process according to the invention has the slight disadvantage that the specific power consumption of the plant increases with the quantity of fine material introduced into the closed circuit of the mill.
  • the process is therefor above all suitable for the case where a plant is used mainly for the production of a finished product for the fineness of which it is designed, and only for a short time for the production of a finished product of greater fineness, as well as for regulating the prescribed fineness of the finished product in those cases where a plant is used for the manufacture of a product of the fineness for which it has been designed.
  • a grinding and'sifting plant of the kind described is so constructed that the sifter has a device for varying the sifting degree.
  • the device should be inexpensive and, on the other hand, should only have to cover a limited fineness range. Two particularly inexpensive devices for varying the sifting degree of a known circulating air sifter are described in the following.
  • the circulating air sifter 2 represented in FIGS. 5 and 6 has an inner scattering chamber 53, a fine material separating chamber 54, concentrically surrounding the said scattering chamber, a scattering plate 55 and, above the latter, a selector wheel 56 in the scattering chamber 53 and a fan wheel 57 above the selector wheel 56.
  • Scattering plate, selector wheel and fan wheel have a common drive 58.
  • the scattering chamber 53 and the fine material separating chamber 54 are connected together at the bottom by louvres 59 and at the top by a connecting channel 510.
  • radially movable slide elements 511 are now provided in the axial region between the selector wheel 56 and fan wheel 57, which slide elements in their end position on the sifter axis side constrict the passage cross section between the chambers occupied by the said wheels 56, 57.
  • These slide elements 511 are secured to radial rods 512 which are guided radially movable in openings 513 in the outer housing 514 and guides 515 on the inner housing 516.
  • Such radial slide elements in circulating air sifters are known per se and are described, for example, in Swiss Pat. Specification No. 277,091.
  • the selector vanes 517, 518, 519 of the selector wheel 56 have different radial dimensions.
  • the number of selector vanes shown and their radial dimension is not essential, and is merely fixed by way of example, solely from points of view of clarity.
  • the selector vanes 517 and 518 are fully effective, in the outer radial end position of the sliding elements 511 only a the selector vanes 517 are fully effective, and-in the end position on the sifter axis side, all the selector vanes 517,518,519 are fully effective.
  • a process for grinding and sifting a granular material which comprises grinding the charge material stream and thereupon sifting the ground material stream and dividing the latter into a coarse material stream and a fine material stream, and returning said course material stream into said charge material stream, a closed circuit of coarse material thus being formed, said fine material stream forming the finished product, in which process a partial stream is taken from said fine material stream and is reintroduced into said closed circuit.

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  • Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Crushing And Grinding (AREA)
  • Disintegrating Or Milling (AREA)
  • Combined Means For Separation Of Solids (AREA)
US805752A 1968-03-21 1969-03-10 Process for grinding and sifting Expired - Lifetime US3586248A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH421168A CH480093A (de) 1968-03-21 1968-03-21 Verfahren und Vorrichtung zum Mahlen und Sichten eines körnigen Gutes, insbesondere von Zement
CH1928268A CH505651A (de) 1968-03-21 1968-12-24 Vorrichtung zum Mahlen und Sichten eines körnigen Gutes, insbesondere von Zement

Publications (1)

Publication Number Publication Date
US3586248A true US3586248A (en) 1971-06-22

Family

ID=25694931

Family Applications (1)

Application Number Title Priority Date Filing Date
US805752A Expired - Lifetime US3586248A (en) 1968-03-21 1969-03-10 Process for grinding and sifting

Country Status (6)

Country Link
US (1) US3586248A (da)
CH (1) CH505651A (da)
DE (1) DE1913440A1 (da)
DK (1) DK136847B (da)
FR (1) FR2004364A1 (da)
GB (1) GB1262670A (da)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3982699A (en) * 1973-12-22 1976-09-28 Heinz Jager Method and plant for producing cement or other material of given fineness and granular structure
US4536980A (en) * 1982-09-24 1985-08-27 Ward Fleming Pin screen
US4654989A (en) * 1983-08-30 1987-04-07 Ward Fleming Vertical three-dimensional image screen
AU605886B2 (en) * 1987-07-09 1991-01-24 Alcan International Limited Method of producing fine particles
EP1129781A1 (de) * 2000-03-03 2001-09-05 KHD Humboldt Wedag AG Verfahren und Anlage zur zweistufigen Sichtung körnigen Gutes
CN117451586A (zh) * 2023-12-22 2024-01-26 山东恒建工程检测有限公司 一种公路建设水泥性能检测装置及其方法

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3124649A1 (de) * 1981-06-23 1983-01-05 Krupp Polysius Ag, 4720 Beckum Verfahren zur regelung einer mahlanlage
DE3152014A1 (de) * 1981-12-31 1983-07-14 Engelbrecht + Lemmerbrock Gmbh + Co, 4520 Melle Verfahren zum schroten von corn-cob-mix
EP0112022A3 (en) * 1982-12-16 1986-09-03 F.L. Smidth & Co. A/S Method of and plant for grinding pulverulent or granular materials
EP0242218B1 (en) * 1986-04-17 1990-08-01 Babcock-Hitachi Kabushiki Kaisha Coal-water slurry producing system
DE3813661A1 (de) * 1988-04-22 1989-11-02 Krupp Polysius Ag Mahlanlage
DE10056158C5 (de) * 2000-11-13 2014-11-13 Thyssenkrupp Industrial Solutions Ag Verfahren und Anlage zur Herstellung von Feingut
CN105833974A (zh) * 2016-04-29 2016-08-10 四川亚东水泥有限公司 基于开闭路联合控制的水泥生产系统及其工艺

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3982699A (en) * 1973-12-22 1976-09-28 Heinz Jager Method and plant for producing cement or other material of given fineness and granular structure
US4536980A (en) * 1982-09-24 1985-08-27 Ward Fleming Pin screen
US4654989A (en) * 1983-08-30 1987-04-07 Ward Fleming Vertical three-dimensional image screen
AU605886B2 (en) * 1987-07-09 1991-01-24 Alcan International Limited Method of producing fine particles
EP1129781A1 (de) * 2000-03-03 2001-09-05 KHD Humboldt Wedag AG Verfahren und Anlage zur zweistufigen Sichtung körnigen Gutes
CN117451586A (zh) * 2023-12-22 2024-01-26 山东恒建工程检测有限公司 一种公路建设水泥性能检测装置及其方法
CN117451586B (zh) * 2023-12-22 2024-03-19 山东恒建工程检测有限公司 一种公路建设水泥性能检测装置及其方法

Also Published As

Publication number Publication date
GB1262670A (en) 1972-02-02
DK136847B (da) 1977-12-05
DK136847C (da) 1978-05-16
DE1913440A1 (de) 1970-01-02
CH505651A (de) 1971-04-15
FR2004364A1 (da) 1969-11-21

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