EP0317935A2 - Method and apparatus for fine grinding - Google Patents

Method and apparatus for fine grinding Download PDF

Info

Publication number
EP0317935A2
EP0317935A2 EP88119353A EP88119353A EP0317935A2 EP 0317935 A2 EP0317935 A2 EP 0317935A2 EP 88119353 A EP88119353 A EP 88119353A EP 88119353 A EP88119353 A EP 88119353A EP 0317935 A2 EP0317935 A2 EP 0317935A2
Authority
EP
European Patent Office
Prior art keywords
mill
ground
cryogen
grinding
vaporized
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
EP88119353A
Other languages
German (de)
French (fr)
Other versions
EP0317935A3 (en
EP0317935B1 (en
Inventor
Andrew Paul Ondush
Richard Donald Ritter
Arthur H. Anderson
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.)
Air Products and Chemicals Inc
Original Assignee
Air Products and Chemicals 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
Family has litigation
Priority to US12563887A priority Critical
Priority to US125638 priority
Application filed by Air Products and Chemicals Inc filed Critical Air Products and Chemicals Inc
Publication of EP0317935A2 publication Critical patent/EP0317935A2/en
Publication of EP0317935A3 publication Critical patent/EP0317935A3/en
Application granted granted Critical
Publication of EP0317935B1 publication Critical patent/EP0317935B1/en
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=22420699&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0317935(A2) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • B02C23/18Adding fluid, other than for crushing or disintegrating by fluid energy
    • 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
    • B02C13/14Disintegrating by mills having rotary beater elements ; Hammer mills with vertical rotor shaft, e.g. combined with sifting devices
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B02CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02CCRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C19/00Other disintegrating devices or methods
    • B02C19/18Use of auxiliary physical effects, e.g. ultrasonics, irradiation, for disintegrating
    • B02C19/186Use of cold or heat for disintegrating

Abstract

A method and apparatus for fine grinding materials normally difficult to grind at ambient temperature, e.g. plastic and elastomeric materials and foodstuffs in a fluid classification type impact mill utilizing liq­uid cryogen to pre-cool the material to be ground, to cool the material and the mill during grinding and to recycle vaporized cryogen from the mill back into the mill as the medium for conveying material to be ground into the mill.

Description

    TECHNICAL FIELD
  • The present invention pertains to fine grinding and especially to fine grinding of plastic and elastomeric materials and foodstuffs.
  • BACKGROUND OF THE PRIOR ART
  • Fine grinding, pulverizing or size reduction all terms used to denote comminution of relatively soft or resilient materials such as rubbers and plastics has been the subject of a great deal of interest and research for many years. In particular the rubber and plastics industry has been interested in fine grinding scrap or reject material in order to recycle the material for reuse. However, in order to make effective use of recycle material the recycle material must be ground to a particle size finer than 80 mesh in order to be mixed with virgin material for reuse.
  • An effective and economically cost justifiable fine grinding system would be an asset to the rubber and plastics industry because of the various states and the federal government making it more and more difficult to dis­pose of scrap rubber and plastic material. Currently there is no economical process for producing powdered rubber or plastic or a particle size finer than 80 mesh. Thus large amounts of scrap and reject material are being stockpiled for recycle or disposition in accordance with current environ­mental laws.
  • In the past several attempts have been made to solve the problem of fine grinding by utilizing different types of grinding (pulverizing, size reducing or comminution) mills which incorporate a liquid cryogen such as liquid nitrogen either before or inside the mill.
  • For example conventional hammer mills have utilized liquid nitrogen both inside the mill and before the mill in a pre-cooler. However over the past decade within which these devices have been used it has been found that the hammer mill cannot grind the tough rubber and plastics economically be­cause of the excessive amount of liquid nitrogen required.
  • Attrition mills have also been modified to use liquid nitrogen both inside and before the mill in a pre-cooler. This also has been done for about 10 years and it is known that the attrition mill cannot grind the tough rubber and plastics economically due to excessive plate wear inside the mill.
  • Lastly air-swept impact mills (fluid classification mills) have been utilized with nitrogen to pre-cool the material to be ground. Although a fine ground material was obtained the economics of the process were un­favorable due to the excessive amounts of liquid nitrogen required.
  • The art is replete with various types of schemes to utilize liquid nitrogen in combination with a grinding mill to effect the grinding of normally resilient or soft materials. U.S. Patents 2,609,150, 2,735,624, 2,919,862, 3,614,001, 3,771,729 and 3,273,294 illustrate the use of a liquid cryogen (liquid nitrogen) to pre-cool and/or cool the grinding mill to achieve a ground product.
  • U.S. Patent 3,771,729 shows a particularly effective pre-cooling ap­paratus for conditioning the material for grinding.
  • Other techniques for grinding materials that are normally soft, vis­cous, plastic or elastomeric in nature at room temperature are illustrated in U.S. Patents 441,951, 637,465, 2,467,318, 3,314,802, 2,347,464, 2,435,503, 2,583,697, 3,647,149, 3,658,259, 2,665,850, 3,734,412, 2,836,368, 2,893,216, 2,974,883, 3,319,895.
  • SUMMARY OF THE INVENTION
  • The present invention pertains to a method and apparatus for fine grinding (e.g. to a -40 mesh particle size) of plastic and elastomeric materials utilizing a fluid classification impact grinding mill combined with a liquid cryogen system to pre-cool the material to be ground, utilizing liquid cryogen inside the mill to cool the material during grinding which also cools the mill and recycle vaporized liquid cryogen for use as the classifying fluid or the sweep fluid for the mill.
  • BRIEF DESCRIPTION OF THE DRAWING
    • FIG. 1 is a schematic elevational view of the system and method ac­cording to the present invention.
    • FIG. 2 is a front elevational view, partially in section, of a fluid classification mill modified in accordance with the present invention.
    • FIG. 3 is a view taken along line 3-3 of FIG. 2.
    • FIG. 4 is a bottom plan view of the manifold according to the present invention.
    DETAILED DESCRIPTION OF THE INVENTION
  • Referring to FIG. 1 the overall system according to the invention is designated generally by the numeral 10. System 10 includes as the central apparatus a fluid classification impact mill 12 such as offered for sale by Mikropul Division of Hosakawa Micron International Inc., Summit, New Jersey, 07910, under the product designation ACM Micro Pulverizer.
  • Material is conveyed to the mill 12 for grinding by means of a transi­tion chute 14 which is connected to an air lock 16 which in turn is con­nected to a cooling conveyor 18. Cooling conveyor 18 is preferably of the type shown and described in U.S. Patent 3,771,729 and offered for sale by Air Products and Chemicals, Inc., Trexlertown, Pennsylvania under the Cryo-­Grind trademark. Cooling conveyor 18 has a feed hopper 22 as well as a conduit 24 for admitting liquid cryogen to the conveyor as shown in the '729 patent. Conveyor 18 can be of any type that will provide means for pre-cooling the material to be ground to its embrittlement temperature. Cooling conveyor 18 can be conveniently disposed on a portable carriage or table 26 and includes dive mechanism 23. Downstream of mill 12 and con­nected to mill 12 via suitable piping 30 is a separator 32 such as a cyclone separator. Cyclone separator 32 has disposed at its discharge opening an air lock 34 to permit discharge of the product into a receptacle or drum 36 without opening the system to ambient atmosphere.
  • A recycle blower 38 receives the vaporized cryogen exiting mill 12, after separation of the product 37 through suitable fluid tight connections and piping 40. Recycle blower 38 conveys the separated vaporized cryogen back to the mill 12 by means of conduit assembly 42 which includes a pres­sure relief valve 44.
  • A suitable conduit 46 conveys liquid cryogen to the mill 12 in a manner as will hereinafter be more fully disclosed.
  • The process according to the invention as practiced in the apparatus or system of FIG. 1 takes place by introducing material to be ground to the cooling conveyor 18 by means of the hopper 22 and air lock 20. As the material is conveyed through the cooling conveyor 18 it is pre-cooled by liquid nitrogen introduced to the cooling conveyor through conduit 24 to cool the material to its embrittling temperature. The material after cooling in cooling conveyor 18 is conveyed through a suitable air lock 16 and transition chute 14 to the fluid classification impact mill 12. As is well known in the art mill 12 can be adjusted to provide product of a given fineness. In the case of the present invention the mill is set to grind the starting material to a size that will pass through an 80 mesh (U.S. Standard) screen. The fine ground material entrained in vaporized cryogen exits the mill 12 in the direction shown by arrow 48 and enters the classifier or cyclone 32 where the particles shown by arrow 50 are separated from the vaporized cryogen and collected as product 37 in product drum 36. The vaporized cryogen exiting the cyclone 32 is conveyed by circuit 40 to the inlet or suction side of blower 38 whereby it is recycled to the fluid classification mill 12 to be used as the classification fluid as will here­inafter be more fully explained. Thus material processed according to the invention can be finely ground very effectively. The process is economical because the vaporized cryogen is recycled to be used as a classification fluid but more importantly the low temperature of the vaporized cryogen is utilized as an aid in cooling of the incoming product and the mill.
  • The process according to the present invention can be operated effec­tively with the following process conditions: Table 1
    Piece of Equipment Process Variable Operating Limits
    Cooling Conveyor Temperature 0°F to -320°F
    Cooling Conveyor Speed 0 to 100 volts
    Fluid Classification Mill Temperature +70°F to -320°F
    Fluid Classification Mill Classifier Speed 0 to 5000 rpm
    Blower Speed 100 to 3500 rpm
    Most common materials can be ground to size utilizing the parameters set out above. Experimentation has shown if the process is operated significantly outside the above limits the particle size required cannot be produced economically.
  • Scrap or recycle tire tread has been ground successfully utilizing the process of the present invention which material has been incorporated into virgin material for remolding.
  • FIG. 2 shows a fluid classification grinding mill such as the ACM Mikro pulverizer identified above which has been modified in accord with the pres­ent invention. Mill 12 includes an inlet chamber 60 containing an inlet conduit 64 which in turn is connected to the transition chute 14 of FIG. 1 by suitable fittings (not shown). Chamber 60 contains means for supporting a central rotor 64 which in turn is connected to the pin rotor 66 which sup­ports a plurality of hammers 68. Chamber 60 has mounted thereon a housing 70 which in turn supports a second housing 72 which contains an outlet con­duit 74 which in turn is connected to the piping 30 as shown in FIG. 1. Disposed within housings 70 and 72 is a separator shaft and bearing hous­ing 4 which in turn supports the rotatable classifier 76. Disposed within housing 70 and surrounding a portion of the rotating classifier 76 is a shroud and baffle ring 78. Material to be ground is introduced to the mill 12 via a feed hopper and auger device 14 as is well known in the art. This basically is the conventional fluid classification impact grinding mill. In normal operation the material to be ground enters the mill and is contacted by hammers 68. A classification fluid (e.g. nitrogen) enters the mill through inlet conduit 64 as shown by arrows 80 and flows through the mill to drive the particles in the direction shown by the arrows. The ground particles pass through the classifier 76 in accordance with the speed of rotation of the classifier and the selected particles are removed with the nitrogen via the arrows as shown. According to the present invention a spray header or manifold 82 is disposed inside of the shroud and baffle ring 78. Spray header 82 is adapted to direct liquid cryogen, e.g. liquid nitro­gen in the direction shown by the hollow arrows 84. Spray header 82 is in turn connected through a suitable fitting 86 to a source of liquid cryogen (not shown). Spray header 82 can be disposed at the top of the shroud and baffle ring, at the bottom thereof as shown by the ghost lines or at any position intermediate thereof depending upon the mill and the degree of cooling and liquid cryogen consumption required. Tests have shown most economical use of liquid cryogen is effected when spray header 82 is dis­posed at the bottom of shroud and baffle ring 78. Liquid cryogen injected into the mill cools not only the mill, but the product as it is being ground. As the cryogen contacts the particles to be ground, it warms up and it vaporizes the vapors forming part of the product arrows 85 which leave the mill 12 and are conducted towards the cycle 32 for separation and recycled to the mill as hereinafter described.
  • Figure 3 shows the shroud and baffle 78 and the housing 70 as well as the spray header 82. Spray header 82 as shown in figure 4 is basically a circular tube containing a plurality of orifices or holes 90 for directing the liquid nitrogen towards the product being ground. Spray header 82 is constructed with a suitable manifold 94 so that the liquid cryogen entering the inlet conduit 96 passes to the orifices 90 without diminution.
  • Utilizing the method and apparatus according to the present invention of the total volume of liquid cryogen (e.g. liquid nitrogen) used, 10-20% is used in the precooler with the balance being used for direct injection into the mill.
  • Having thus described our invention, what is desired to be secured by Letters Patent of the United States is set forth in the appended claims.

Claims (12)

1. A method for utilizing a fluid classification impact grinding mill for fine grinding comprising the steps of:
pre-cooling the material to be ground to a temperature below its embrittlement temperature;
injecting said pre-cooled material into said mill while simultane­ously injecting a liquid cryogen into said mill;
recovering said ground material and cryogen vaporized in said mill;
separating said vaporized cryogen from said ground material and recycling said vaporized cryogen to said mill as a classifying medium.
2. A method according to Claim 1 wherein said liquid cryogen is ni­trogen.
3. A method according to Claim 1 wherein said pre-cooling is accom­plished by utilizing liquid cryogen.
4. A method according to Claim 1 wherein said ground material is re­covered as a product.
5. A method according to Claim 1 wherein the ground material has a particle size that will pass a 40 mesh screen.
6. A closed system for fine grinding rubber and plastic material com­prising in combination
means for collecting and conveying said material to a fluid classification grinding mill said means including means to pre-cool said material to below its embrittlement temperature;
a fluid classification grinding mill connected in fluid tight relation to said collecting and conveying means said mill including means to inject a liquid cryogen onto said material during grinding;
removal means to conduct ground material and cryogen vaporized in said mill to separator means;
separator means to separate such ground material from said vaporized cryogen;
recirculation means to convey such vaporized cryogen from said separator means to said mill; and
collection means to recover said ground material as a product.
7. A system according to Claim 6 wherein said collecting and con­veying means includes a feed hopper and a cooling conveyor with an air lock therebetween.
8. A system according to Claim 6 wherein an air lock is disposed between said collecting and conveying means and said fluid classification grinding mill.
9. A system according to Claim 6 wherein said separator means in­cludes a cyclone type separator.
10. A system according to Claim 6 wherein said recirculation means includes a blower the suction side connected to said mill through said cyclone and said output connected to said fluid classification mill.
11. In a fluid classification type grinding mill of the type wherein a normal gaseous fluid is used to convey particles to be ground into the mill and ground particles out of such mill, the improvement comprising:
means to inject a liquid cryogen into the particles during grind­ing to cool said particles and said mill.
12. An apparatus according to Claim 11 wherein said means includes a spray header disposed in said mill above active grinding devices with means to direct said cryogen toward said active grinding devices.
EP88119353A 1987-11-25 1988-11-21 Method and apparatus for fine grinding Expired - Lifetime EP0317935B1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US12563887A true 1987-11-25 1987-11-25
US125638 1987-11-25

Publications (3)

Publication Number Publication Date
EP0317935A2 true EP0317935A2 (en) 1989-05-31
EP0317935A3 EP0317935A3 (en) 1990-01-03
EP0317935B1 EP0317935B1 (en) 1992-04-29

Family

ID=22420699

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88119353A Expired - Lifetime EP0317935B1 (en) 1987-11-25 1988-11-21 Method and apparatus for fine grinding

Country Status (8)

Country Link
EP (1) EP0317935B1 (en)
JP (1) JPH01168361A (en)
KR (1) KR910006231B1 (en)
BR (1) BR8806087A (en)
CA (1) CA1328862C (en)
DE (1) DE3870587D1 (en)
PT (1) PT89070A (en)
ZA (1) ZA888809B (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0507205A2 (en) * 1991-04-05 1992-10-07 Air Products And Chemicals, Inc. Process for the production of ultra-fine polymeric fibers
EP0584712A1 (en) * 1992-08-21 1994-03-02 Debio Recherche Pharmaceutique S.A. Ultra-centrifugal mill and its implementation for cryogenically milling heat-sensitive material
EP0610162A2 (en) * 1993-01-28 1994-08-10 PRO.CO.GEN. PROGETTAZIONI E COSTRUZIONI GENERALI S.p.A. Installation for the cryogenic transformation and sorting of solid municipal waste
US5887803A (en) * 1995-09-07 1999-03-30 Messer Griesheim Gmbh Process and apparatus for grinding and sifting a product
ES2188329A1 (en) * 2000-09-15 2003-06-16 Consejo Superior Investigacion Cryogenic controlled grinding of aromatic polyester mixtures consists of controlled transesterification of polycondensation polymers by hot moulding
WO2008109637A1 (en) * 2007-03-06 2008-09-12 Archer-Daniels-Midland Company Method and apparatus for producing cocoa products
CN103272674A (en) * 2013-05-22 2013-09-04 张家港市华丰油脂有限公司 Airflow vortex pulverizing machine for extracting cotton proteins from cottonseed meal
EP3764030A1 (en) * 2019-07-11 2021-01-13 Air Liquide Deutschland GmbH Method and device for cooling products

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100842300B1 (en) * 2007-05-21 2008-06-30 한국기계연구원 Powder classification and separation apparatus media mill system
CN110026283B (en) * 2019-04-09 2020-08-11 凤台县农盼水稻机插服务专业合作社 Low-temperature crop straw smashing device and operation method thereof

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3771729A (en) * 1971-06-17 1973-11-13 Air Prod & Chem Cryogenic comminution system
US4222527A (en) * 1979-02-22 1980-09-16 Union Carbide Corporation Cryopulverizing packed bed control system
DE2952363A1 (en) * 1979-12-24 1981-07-02 Linde Ag, 6200 Wiesbaden METHOD AND DEVICE FOR CRUSHING SUBSTANCES AT LOW TEMPERATURES

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5472563A (en) * 1977-11-21 1979-06-11 Nippon Oxygen Co Ltd Method of low temperature crushing

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3771729A (en) * 1971-06-17 1973-11-13 Air Prod & Chem Cryogenic comminution system
US4222527A (en) * 1979-02-22 1980-09-16 Union Carbide Corporation Cryopulverizing packed bed control system
DE2952363A1 (en) * 1979-12-24 1981-07-02 Linde Ag, 6200 Wiesbaden METHOD AND DEVICE FOR CRUSHING SUBSTANCES AT LOW TEMPERATURES

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0507205A2 (en) * 1991-04-05 1992-10-07 Air Products And Chemicals, Inc. Process for the production of ultra-fine polymeric fibers
EP0507205A3 (en) * 1991-04-05 1993-06-23 Air Products And Chemicals, Inc. Process for the production of ultra-fine polymeric fibers
EP0584712A1 (en) * 1992-08-21 1994-03-02 Debio Recherche Pharmaceutique S.A. Ultra-centrifugal mill and its implementation for cryogenically milling heat-sensitive material
US5431348A (en) * 1992-08-21 1995-07-11 Debio Recherche Pharmaceutique Sa Ultracentrifugal disintegrator and its use for the cryocomminution of heat sensitive material
EP0610162A2 (en) * 1993-01-28 1994-08-10 PRO.CO.GEN. PROGETTAZIONI E COSTRUZIONI GENERALI S.p.A. Installation for the cryogenic transformation and sorting of solid municipal waste
EP0610162A3 (en) * 1993-01-28 1995-02-01 Pro Co Gen Progettazioni E Cos Installation for the cryogenic transformation and sorting of solid municipal waste.
US5887803A (en) * 1995-09-07 1999-03-30 Messer Griesheim Gmbh Process and apparatus for grinding and sifting a product
ES2188329A1 (en) * 2000-09-15 2003-06-16 Consejo Superior Investigacion Cryogenic controlled grinding of aromatic polyester mixtures consists of controlled transesterification of polycondensation polymers by hot moulding
WO2008109637A1 (en) * 2007-03-06 2008-09-12 Archer-Daniels-Midland Company Method and apparatus for producing cocoa products
CN103272674A (en) * 2013-05-22 2013-09-04 张家港市华丰油脂有限公司 Airflow vortex pulverizing machine for extracting cotton proteins from cottonseed meal
CN103272674B (en) * 2013-05-22 2015-12-02 张家港市华丰油脂有限公司 A kind of air-flow vortex pulverizing mill for extracting cotton protein from cotton dregs
EP3764030A1 (en) * 2019-07-11 2021-01-13 Air Liquide Deutschland GmbH Method and device for cooling products

Also Published As

Publication number Publication date
PT89070A (en) 1989-09-14
EP0317935A3 (en) 1990-01-03
KR890007796A (en) 1989-07-05
KR910006231B1 (en) 1991-08-17
BR8806087A (en) 1989-08-08
CA1328862C (en) 1994-04-26
ZA888809B (en) 1990-07-25
JPH01168361A (en) 1989-07-03
DE3870587D1 (en) 1992-06-04
EP0317935B1 (en) 1992-04-29

Similar Documents

Publication Publication Date Title
US5203511A (en) Method for fine grinding
US4863106A (en) Process for low temperature comminution of scrap tires
CA2546298C (en) Process and apparatus for manufacturing crumb and powder rubber
US5588600A (en) Process and apparatus for making crumb rubber from vehicle tires
US4025990A (en) Process for reclaiming rubber, metal and fabric from whole tires
EP0317935B1 (en) Method and apparatus for fine grinding
US5524838A (en) Method and apparatus for processing tires to reclaim rubber, metal, and fabric
US5597123A (en) Ultra-high energy cryogenic impact system
US4251034A (en) System for reclaiming plastic from metal plated plastic scrap
EP0068502A2 (en) Method and apparatus for recovering thermoplastic from coated fabric scrap
US5195695A (en) Apparatus for fine grinding
US5887803A (en) Process and apparatus for grinding and sifting a product
EP0222760B1 (en) Comminution of coal, ores and industrial minerals and rocks
CN107511392A (en) A kind of electron wastes harmless disassembly and resource classification reclaimer and method
CN105618235A (en) Continuous producing and preparing device for carbon graphite
EP0014289A1 (en) Method for separating plastics and metal from metallized plastic
US5002232A (en) Apparatus for shredding cans
JPH0739780A (en) Grinding equipment
JPH06170272A (en) Method for pulverizing frp waste and device for the same
KR960016585B1 (en) Method for recycling waste polystyrene foam
LT5314B (en) Device for recycling rubber-containing waste
HU211770B (en) Arrangement and apparatus for handling grinding, recycling of rubber-wastes
JPS6443353A (en) Dry finely grinding apparatus
JPH0747295A (en) Method for pulverizing method and device
JP2000297304A (en) Alloy powder manufacturing equipment

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): BE CH DE ES FR GB IT LI NL

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): BE CH DE ES FR GB IT LI NL

17P Request for examination filed

Effective date: 19900223

17Q First examination report despatched

Effective date: 19900727

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): BE CH DE ES FR GB IT LI NL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19920429

Ref country code: LI

Effective date: 19920429

Ref country code: ES

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19920429

Ref country code: CH

Effective date: 19920429

Ref country code: BE

Effective date: 19920429

REF Corresponds to:

Ref document number: 3870587

Country of ref document: DE

Date of ref document: 19920604

ITF It: translation for a ep patent filed

Owner name: DR. ING. A. RACHELI & C.

ET Fr: translation filed
REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19921121

26 Opposition filed

Opponent name: LINDE AKTIENGESELLSCHAFT, WIESBADEN

Effective date: 19930129

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19921121

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19930730

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19930803

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: OPPOSITION REJECTED

27O Opposition rejected

Effective date: 19940325

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20051121