GB2068260A - Selecting grating for granulating mill - Google Patents

Selecting grating for granulating mill Download PDF

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Publication number
GB2068260A
GB2068260A GB8040467A GB8040467A GB2068260A GB 2068260 A GB2068260 A GB 2068260A GB 8040467 A GB8040467 A GB 8040467A GB 8040467 A GB8040467 A GB 8040467A GB 2068260 A GB2068260 A GB 2068260A
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GB
United Kingdom
Prior art keywords
grating
selecting
rotor
plate
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.)
Granted
Application number
GB8040467A
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GB2068260B (en
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PREVIERO Sas
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PREVIERO Sas
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Publication of GB2068260A publication Critical patent/GB2068260A/en
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Publication of GB2068260B publication Critical patent/GB2068260B/en
Expired legal-status Critical Current

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Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B07SEPARATING SOLIDS FROM SOLIDS; SORTING
    • B07BSEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
    • B07B1/00Sieving, screening, sifting, or sorting solid materials using networks, gratings, grids, or the like
    • B07B1/46Constructional details of screens in general; Cleaning or heating of screens
    • B07B1/4609Constructional details of screens in general; Cleaning or heating of screens constructional details of screening surfaces or meshes
    • B07B1/469Perforated sheet-like material
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B02CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02CCRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C13/00Disintegrating by mills having rotary beater elements ; Hammer mills
    • B02C13/26Details
    • B02C13/282Shape or inner surface of mill-housings
    • B02C13/284Built-in screens
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B02CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02CCRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C18/00Disintegrating by knives or other cutting or tearing members which chop material into fragments
    • B02C18/06Disintegrating by knives or other cutting or tearing members which chop material into fragments with rotating knives
    • B02C18/14Disintegrating by knives or other cutting or tearing members which chop material into fragments with rotating knives within horizontal containers
    • B02C18/148Disintegrating by knives or other cutting or tearing members which chop material into fragments with rotating knives within horizontal containers specially adapted for disintegrating plastics, e.g. cinematographic films
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B02CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02CCRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C18/00Disintegrating by knives or other cutting or tearing members which chop material into fragments
    • B02C18/06Disintegrating by knives or other cutting or tearing members which chop material into fragments with rotating knives
    • B02C18/16Details
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B02CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02CCRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C23/00Auxiliary 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
    • B02C23/08Separating or sorting of material, associated with crushing or disintegrating
    • B02C23/16Separating or sorting of material, associated with crushing or disintegrating with separator defining termination of crushing or disintegrating zone, e.g. screen denying egress of oversize material
    • B02C2023/165Screen denying egress of oversize material

Landscapes

  • Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Crushing And Pulverization Processes (AREA)
  • Combined Means For Separation Of Solids (AREA)
  • Crushing And Grinding (AREA)

Abstract

Each bore (2) of the plate (1) forming a selecting grating for a granulating mill houses a replaceable bush (3) having a hardness greater than that of said plate (1). A higher stress resistance and a lower wear are thus obtained and the bushes (3), when worn, may be replaced with new ones without any necessity of replacing the entire grating. Each bush (3) is provided with a cutting edge (6) to facilitate cutting of the material being granulated and each bush (3) may be turned in its bore (2) when the cutting edge (6) becomes locally worn to prolong bush life. <IMAGE>

Description

SPECIFICATION Selecting grating for granulating mill The present invention relates to a selecting grating for granulating mill.
As known, a granulating mill is a machine capable of reducing pieces of material of every kind and shape to the size of small granules. It generally comprises a rotor with horizontal axis, which is rotated inside a stator cavity, which communicates upwards with a supply hopper and is closed downwards by a selecting grating having an arcuate shape.
The rotor is provided with radial blades, which, while the rotor is rotating, cooperate with stationary stator counter blades to cut and crumble gradually the material so much that it is reduced to the size of granules capable of passing through the bores of the selecting grating and thus reaching a collecting chamber located below.
A problem of the presently known granulating mills is represented by the wear of the selecting grating, which is subjected to high stresses and resulting deformations, especially when, as it often occurs, a granule having already reduced transversal size but still exaggerated length has come into a bore of the grating and, while it is in that condition, is struck by a blade of the rotor and strongly subjected to tearing stress against the bore wall. Such a drawback, which occurs particularly with rubber-like products, causes the necessity of periodic substitutions of the grating with consequent expenses.
The object of the present invention is to realize a selecting grating for granulating mill, which is subjected to lower wear and involves, in any case, reduced costs of maintenance.
According to the invention this object is attained by means of a selecting grating, comprising a plate provided with bores, characterized in that each bore houses a replaceable bushing having a hardness greater than that of said plate.
The use of bushings of greater hardness obviously allows a higher stress resistance and, therefore, a lower wear and a longer duration. Moreover, once the bushings have worn, it is not necessary to replace the entire grating, but only the bushings. This obviously results in a very reduced cost of maintenance.
Each bushing is preferably provided with an inner cutting edge at its end which, in the use, is faced to the rotor. Such a cutting edge has the function of facilitating the shearing rupture, instead of the tearing rupture, of the granules already partially inserted in the bores of the grating and, due to its hardness, it wears very slowly, assuring an excellent quality of the product for a long time. As the rotor is always rotated in the same sense and it is always the same half of the cutting edge, which works and, consequently wears, it is also possible to double the duration of the cutting edge and, therefore, of the bushing by rotating at a suitable time the bushing through an angle of 180 . The other half of the cutting edge, which is in perfect conditions, is thus ready to work.
The features of the present invention will be better understood by referring, by way of example, to the accompanying drawings, in which: Figure 1 shows a top plan view, developed in a plane and without any bushings, of a selecting grating according to the invention; Figure 2 shows the grating as provided with bushings, sectioned along the line ll-ll of Fig.
1 and with the bending foreseen for its use; Figure 3 shows a part of said grating in top plan view with respect to Fig. 2; Figure 4 shows the same part of the grating in bottom plan view with respect to Fig. 2.
The selecting grating illustrated in the drawings comprises a metallic plate 1 with distributed circular bores 2, which is developed in a plane in Fig. 1 but is really destined to be employed in a granulating mill with the arcuate shape illustrated in Fig. 2.
In each of said bores there is inserted a replaceable bushing 3, which is held in position by a turned end edge 4 thereof and by a Seeger ring 5, which cooperate with opposite faces of the plate 1. The material of the bushings is chosen in such a way as to provide the same bushings with a hardness and, therefore, a stress resistance much higher than that of the plate 1.
As it may be noted from Fig. 2, the end of each bushing 3 which is faced to the center of curvature of the plate 1 and, in the use, to the rotor of the granulating mill, is provided with a circular inner cavity edge 6, which has the function of making easier the cut, by the rotor blades, of the possible granules of exaggerated length, which are already partially inserted in the axial bores of the bushings 3.
For the replacement of the bushings 3, as well as for their rotation of 180 once the first half of the cutting edge 6 has worn, it is sufficient to remove momentarily the Seeger rings 5.
1. Selecting grating for granulating mill, comprising a plate providing with bores, characterized in that each bore houses a replaceable bushing having a hardness greater than that of said plate.
2. Selecting grating according to claim 1, characterized in that one end of said bushing is provided with an inwardly faced cutting edge.
3. Selecting grating according to claim 1, characterized in that said bushing is releasably held inside said bore by an outwardly turned end edge thereof and by a Seeger ring, both of which cooperate with opposite faces of said
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (11)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Selecting grating for granulating mill The present invention relates to a selecting grating for granulating mill. As known, a granulating mill is a machine capable of reducing pieces of material of every kind and shape to the size of small granules. It generally comprises a rotor with horizontal axis, which is rotated inside a stator cavity, which communicates upwards with a supply hopper and is closed downwards by a selecting grating having an arcuate shape. The rotor is provided with radial blades, which, while the rotor is rotating, cooperate with stationary stator counter blades to cut and crumble gradually the material so much that it is reduced to the size of granules capable of passing through the bores of the selecting grating and thus reaching a collecting chamber located below. A problem of the presently known granulating mills is represented by the wear of the selecting grating, which is subjected to high stresses and resulting deformations, especially when, as it often occurs, a granule having already reduced transversal size but still exaggerated length has come into a bore of the grating and, while it is in that condition, is struck by a blade of the rotor and strongly subjected to tearing stress against the bore wall. Such a drawback, which occurs particularly with rubber-like products, causes the necessity of periodic substitutions of the grating with consequent expenses. The object of the present invention is to realize a selecting grating for granulating mill, which is subjected to lower wear and involves, in any case, reduced costs of maintenance. According to the invention this object is attained by means of a selecting grating, comprising a plate provided with bores, characterized in that each bore houses a replaceable bushing having a hardness greater than that of said plate. The use of bushings of greater hardness obviously allows a higher stress resistance and, therefore, a lower wear and a longer duration. Moreover, once the bushings have worn, it is not necessary to replace the entire grating, but only the bushings. This obviously results in a very reduced cost of maintenance. Each bushing is preferably provided with an inner cutting edge at its end which, in the use, is faced to the rotor. Such a cutting edge has the function of facilitating the shearing rupture, instead of the tearing rupture, of the granules already partially inserted in the bores of the grating and, due to its hardness, it wears very slowly, assuring an excellent quality of the product for a long time. As the rotor is always rotated in the same sense and it is always the same half of the cutting edge, which works and, consequently wears, it is also possible to double the duration of the cutting edge and, therefore, of the bushing by rotating at a suitable time the bushing through an angle of 180 . The other half of the cutting edge, which is in perfect conditions, is thus ready to work. The features of the present invention will be better understood by referring, by way of example, to the accompanying drawings, in which: Figure 1 shows a top plan view, developed in a plane and without any bushings, of a selecting grating according to the invention; Figure 2 shows the grating as provided with bushings, sectioned along the line ll-ll of Fig. 1 and with the bending foreseen for its use; Figure 3 shows a part of said grating in top plan view with respect to Fig. 2; Figure 4 shows the same part of the grating in bottom plan view with respect to Fig. 2. The selecting grating illustrated in the drawings comprises a metallic plate 1 with distributed circular bores 2, which is developed in a plane in Fig. 1 but is really destined to be employed in a granulating mill with the arcuate shape illustrated in Fig. 2. In each of said bores there is inserted a replaceable bushing 3, which is held in position by a turned end edge 4 thereof and by a Seeger ring 5, which cooperate with opposite faces of the plate 1. The material of the bushings is chosen in such a way as to provide the same bushings with a hardness and, therefore, a stress resistance much higher than that of the plate 1. As it may be noted from Fig. 2, the end of each bushing 3 which is faced to the center of curvature of the plate 1 and, in the use, to the rotor of the granulating mill, is provided with a circular inner cavity edge 6, which has the function of making easier the cut, by the rotor blades, of the possible granules of exaggerated length, which are already partially inserted in the axial bores of the bushings 3. For the replacement of the bushings 3, as well as for their rotation of 180 once the first half of the cutting edge 6 has worn, it is sufficient to remove momentarily the Seeger rings 5. CLAIMS
1. Selecting grating for granulating mill, comprising a plate providing with bores, characterized in that each bore houses a replaceable bushing having a hardness greater than that of said plate.
2. Selecting grating according to claim 1, characterized in that one end of said bushing is provided with an inwardly faced cutting edge.
3. Selecting grating according to claim 1, characterized in that said bushing is releasably held inside said bore by an outwardly turned end edge thereof and by a Seeger ring, both of which cooperate with opposite faces of said plate.
4. A selecting grating for a granulating mill substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.
5. A granulating mill comprising a rotor rotatably mounted with a stator casing, said stator casing comprising a selecting grating in the form of a plate provided with bores, characterised in that each bore houses a replaceable bushing having a hardness greater than that of said plate.
6. A granulating mill according to claim 5, wherein said rotor is provided with at least one radially extending blade.
7. A grating mill according to claim 6, wherein said stator casing is provided with at least one counter blade.
8. A grating mill according to any one of claims 5 to 7, wherein said rotor is mounted so as to be rotatable in use about a substantially horizontal axis.
9. A grating mill according to any one of claims 5 to 8, comprising supply hopper means located above said stator casing and communicating therewith.
10. A grating mill according to any one of claims 5 to 9, comprising a granulated material collecting chamber located beneath said stator casing and communicating therewith through said selecting grating.
11. A grating mill substantially as hereinbefore described comprising a selecting grating substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.
GB8040467A 1980-01-30 1980-12-17 Selecting grating for granulating mill Expired GB2068260B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT2062880U IT8020628V0 (en) 1980-01-30 1980-01-30 SELECTOR GRID FOR GRANULATOR MILL.

Publications (2)

Publication Number Publication Date
GB2068260A true GB2068260A (en) 1981-08-12
GB2068260B GB2068260B (en) 1983-05-25

Family

ID=11169756

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8040467A Expired GB2068260B (en) 1980-01-30 1980-12-17 Selecting grating for granulating mill

Country Status (8)

Country Link
JP (1) JPS615954Y2 (en)
AT (1) AT378131B (en)
BE (1) BE887288A (en)
DE (1) DE3100097A1 (en)
ES (1) ES255240Y (en)
FR (1) FR2474352B1 (en)
GB (1) GB2068260B (en)
IT (1) IT8020628V0 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0795352A1 (en) * 1996-03-11 1997-09-17 Albert Hoffmann GmbH Plate or similar material shredding device
CN108421609A (en) * 2018-05-18 2018-08-21 贵州杉海沿环保科技有限责任公司 Refuse landfill rubbish apparatus for crushing and treating
CN110433923A (en) * 2019-08-13 2019-11-12 湖北力帝机床股份有限公司 Nonferrous metal crusher lattice structure

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT8453419V0 (en) * 1984-05-22 1984-05-22 Morando S P A Off PERFORATED CYLINDER FOR CLAY SELECTOR MACHINES
ES2154149B1 (en) * 1998-05-27 2001-12-01 Serveis De Produccio Empresari IMPROVEMENTS IN FIBER BOARD FLOOR TRANSPORTER SYSTEMS.
CN102814210A (en) * 2012-08-23 2012-12-12 何一标 Sieve plate of hammerhead crusher

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB226888A (en) * 1923-10-03 1925-01-05 Jeffrey Mfg Co Improvements in pulverizing, shredding and like machines
GB729938A (en) * 1952-09-03 1955-05-11 Samuel Royston Griffin Improvements in and relating to screen plates more particularly for the treatment ofmetallic ores
FR1351665A (en) * 1963-02-07 1964-02-07 Ferdinand Mohr Hole screen
US3900393A (en) * 1973-11-05 1975-08-19 Randtron Rubber grommet array for sizing screens
DE2532379C3 (en) * 1975-07-19 1981-09-10 Gustav Schade Maschinenfabrik Gmbh & Co, 4600 Dortmund Sieve plate

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0795352A1 (en) * 1996-03-11 1997-09-17 Albert Hoffmann GmbH Plate or similar material shredding device
US5950940A (en) * 1996-03-11 1999-09-14 Albert Hoffmann Gmbh Apparatus for comminuting sheet metal or similar material
CN108421609A (en) * 2018-05-18 2018-08-21 贵州杉海沿环保科技有限责任公司 Refuse landfill rubbish apparatus for crushing and treating
CN108421609B (en) * 2018-05-18 2023-09-12 贵州杉海沿环保科技有限责任公司 Garbage crushing treatment device for garbage landfill
CN110433923A (en) * 2019-08-13 2019-11-12 湖北力帝机床股份有限公司 Nonferrous metal crusher lattice structure

Also Published As

Publication number Publication date
FR2474352A1 (en) 1981-07-31
GB2068260B (en) 1983-05-25
JPS615954Y2 (en) 1986-02-22
JPS56159141U (en) 1981-11-27
ES255240Y (en) 1981-10-01
IT8020628V0 (en) 1980-01-30
AT378131B (en) 1985-06-25
ATA6381A (en) 1984-11-15
ES255240U (en) 1981-03-16
DE3100097A1 (en) 1981-11-26
FR2474352B1 (en) 1985-09-13
BE887288A (en) 1981-05-14

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PCNP Patent ceased through non-payment of renewal fee