EP0140613A2 - Appareil et méthode permettant d'obtenir un produit broyé à partir d'un matériau d'alimentation solide - Google Patents

Appareil et méthode permettant d'obtenir un produit broyé à partir d'un matériau d'alimentation solide Download PDF

Info

Publication number
EP0140613A2
EP0140613A2 EP84306892A EP84306892A EP0140613A2 EP 0140613 A2 EP0140613 A2 EP 0140613A2 EP 84306892 A EP84306892 A EP 84306892A EP 84306892 A EP84306892 A EP 84306892A EP 0140613 A2 EP0140613 A2 EP 0140613A2
Authority
EP
European Patent Office
Prior art keywords
comminuted
feed material
housing
crusher
product
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.)
Withdrawn
Application number
EP84306892A
Other languages
German (de)
English (en)
Other versions
EP0140613A3 (fr
Inventor
Henry Edward Hill
Alistair Scott Murray
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.)
CROFT IMPRESA Ltd
Original Assignee
CROFT IMPRESA Ltd
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 CROFT IMPRESA Ltd filed Critical CROFT IMPRESA Ltd
Publication of EP0140613A2 publication Critical patent/EP0140613A2/fr
Publication of EP0140613A3 publication Critical patent/EP0140613A3/fr
Withdrawn legal-status Critical Current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
    • B02C13/00—Disintegrating by mills having rotary beater elements ; Hammer mills
    • B02C13/14—Disintegrating by mills having rotary beater elements ; Hammer mills with vertical rotor shaft, e.g. combined with sifting devices
    • B02C13/18—Disintegrating by mills having rotary beater elements ; Hammer mills with vertical rotor shaft, e.g. combined with sifting devices with beaters rigidly connected to the rotor
    • B02C13/1807—Disintegrating by mills having rotary beater elements ; Hammer mills with vertical rotor shaft, e.g. combined with sifting devices with beaters rigidly connected to the rotor the material to be crushed being thrown against an anvil or impact plate
    • B02C13/1835—Disintegrating by mills having rotary beater elements ; Hammer mills with vertical rotor shaft, e.g. combined with sifting devices with beaters rigidly connected to the rotor the material to be crushed being thrown against an anvil or impact plate by means of beater or impeller elements fixed in between an upper and lower rotor disc
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C13/00—Disintegrating by mills having rotary beater elements ; Hammer mills
    • B02C13/14—Disintegrating by mills having rotary beater elements ; Hammer mills with vertical rotor shaft, e.g. combined with sifting devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C23/00—Auxiliary 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
    • B02C23/18—Adding fluid, other than for crushing or disintegrating by fluid energy
    • B02C23/24—Passing gas through crushing or disintegrating zone
    • B02C23/32—Passing gas through crushing or disintegrating zone with return of oversize material to crushing or disintegrating zone
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C13/00—Disintegrating by mills having rotary beater elements ; Hammer mills
    • B02C13/14—Disintegrating by mills having rotary beater elements ; Hammer mills with vertical rotor shaft, e.g. combined with sifting devices
    • B02C13/18—Disintegrating by mills having rotary beater elements ; Hammer mills with vertical rotor shaft, e.g. combined with sifting devices with beaters rigidly connected to the rotor
    • B02C13/1807—Disintegrating by mills having rotary beater elements ; Hammer mills with vertical rotor shaft, e.g. combined with sifting devices with beaters rigidly connected to the rotor the material to be crushed being thrown against an anvil or impact plate
    • B02C2013/1885—Disintegrating by mills having rotary beater elements ; Hammer mills with vertical rotor shaft, e.g. combined with sifting devices with beaters rigidly connected to the rotor the material to be crushed being thrown against an anvil or impact plate of dead bed type

Definitions

  • This invention relates to an apparatus for and a method of obtaining a comminuted product from a solid feed material.
  • British Patent SpecificationsNos. 645,673, 522,339 and 386,698 disclose examples of methods and apparatus for fine grinding where a feed material with a generally small particle size, usually considerably less than 1cm, is ground down to produce a fines output.
  • the apparatus of these three specifications grinds the material by causing it to come into contact with components of the apparatus, for example beaters, grinding rings or grinding bodies.
  • the construction of these grinding apparatus is such that they cannot grind large particles (for example, greater than about 1cm) nor can they operate economically with highly abrasive materials due to the wear and tear which would result from contact with the grinding components.
  • British Patent Specifications Nos. 1,579,295 and 1,531,254 disclose examples of crushing apparatus which use two counter-rotating components to crush material by contact of the material with these components. Problems often arise where counter-rotating components are used due to gyroscopic effects. In addition, the components are subject to a considerable amount of erosion and need continual attention and maintenance. One way of attempting to reduce such erosion is disclosed in United States Patent Specifications Nos. 3,180,852 and 3,162,382 where centrifugal pulverisers are provided for reducing the wear on moving parts by incorporating angle members to trap matter centrifugally flung from a rotor whereby a protective surface is built up. However, the problems involved in using two counter-rotating parts are not overcome.
  • a method of obtaining a comminuted product at least a major proportion of which is smaller than 150um from a solid feed material at least a major proportion of which is larger than lcm which method comprises centrifugally flinging the feed material towards an impact surface which is composed partially or wholly of such material whereby the feed material is comminuted; and entraining in a predominantly upward airflow a portion of the comminuted material comprising particles of less than a given size, to classify the particles to produce the product.
  • an apparatus suitable for carrying out the method according to the one aspect of the present invention comprises a housing having a lower region forming a crusher, an upper region forming a classifier, an inlet for a solid feed material, and an outlet for a product
  • the crusher comprises: means which, in use, cause the feed material to be flung towards an impact surface in said lower region of the housing, said means and the disposition of the lower region of the housing being such that some of the feed material is retained, by gravity and friction forces, in said lower region of the housing so that the impact surface is composed partially or wholly of the material so retained, whereby the material is comminuted; and means for causing during use of the apparatus a predominantly upward airflow from the lower region to the upper region of the housing which airflow entrains a portion of the comminuted material and conveys it to the upper region of the housing for classifying said portion of the comminuted material according to particle size to produce said product.
  • equipment comprising:
  • the crusher comprises a rotor which is adapted to rotate about a vertical or substantially vertical axis and which, in use, causes the feed material to be flung centrifugally towards the impact surface.
  • the given size will vary according to the desired requirements for the characteristics of the product and is dependent on the velocity of material leaving the rotor, the velocity of the airflow and the type and density of the feed material.
  • the apparatus of the invention can be constructed by modifying a crusher of the kind which utilise stonebeds or crushing beds derived from the same material as that which is to be comminuted, either by impact or attrition or interparticle comminution.
  • a crusher of this type is described in British Patent Specification No. 1439639, the matter contained therein being herein incorporated by reference.
  • the crusher of British Patent Specification No. 1439639, and the method of crushing described therein give rise to a certain amount of a "fine product" which heretofore has merely been a byproduct of the crushing process.
  • fine product is used to describe particles having a size of less than 150 ⁇ m.
  • the lower region of the housing is provided with a lid portion having one or more aperture through which said predominantly upward airflow can pass for conveying said portion of comminuted material to the upper region of the housing.
  • the classifier comprises a double cone separator having an outer cone for receiving said predominantly upward airflow and an inner cone through which comminuted material comprising particles greater than a given size can be returned to the crusher.
  • Figure 1 shows a portion of a crusher such as that described in British Patent Specification No. 1439639 which has been modified to provide an apparatus in accordance with the present invention and which is generally designated by reference numeral 10.
  • Large amounts of a "fine product" are internally circulating, within the confines of a housing 12 of the crusher, on an air current caused by the fan effect of the rotor 13.
  • the airflow is caused to circulate in an upwards direction, i.e. vertically upwards from the horizontal plane of the rotor 13.
  • One important modification is the construction of a lid 1 of the housing 12 as a removable portion, rather than as an integral part of the housing.
  • Arrow A indicates the direction of the predominant air flow within the housing; arrow F 1 indicates the incoming feed; and reference numeral 16 indicates a dust flap.
  • a "double cone separator”, generally designated by reference numeral 11, is attached over the portion of the crusher shown in Figure 1, thereby making it possible to extract the "fine airborne material into this double cone separator.
  • the double cone separator is constructed as follows:
  • vanes 21 which can be mechanically adjusted from the outside of the encapsulating outer cone 19.
  • a duct 17 is led from the inner cone 18 to the outside upper end of the larger, outer cone 19.
  • This duct 17 is attached to a suction fan which in turn is in series with a cyclone.
  • the lower end of the smaller, inner cone 18 is led back into a feed hopper 22 of the crusher where it is sealed to the feed hopper structure.
  • the "fine" fraction of material exits via a fan duct and ultimately discharges the required fines into a cyclone for future reclamation, while the coarse material falls down the inner cone 18 and is discharged back into the crusher 10 via a sealed joint into the crusher feed system.
  • the arrows F indicate the "fine" material which is to be classified, and the arrow O represents the tailings which are returned to the crushing chamber 23 of the crusher 10.
  • the particles in the comminuted material which are not entrained in the upwards airflow fall through a discharge chute 24 and may be returned to the feed hopper of the crusher 10 by means of conveyor belts 25, 26.
  • FIG. 3 shows an alternative arrangement for using a crusher in accordance with another embodiment of the present invention (and shown in Figure 4).
  • a feed hopper 30 is arranged to supply a feed material fed into the hopper 30 to a table feeder 32.
  • a first feed conveyor 34 is arranged to transport material from the table feeder 32 to an inlet of the crusher, generally designated by reference 10' in Figure 3.
  • coarse material is discharged at an outlet of the crusher 10' to be returned by means of a second conveyor 36 to the first conveyor 34 for recycling to the inlet of the crusher 10'.
  • a screen 38 may be used for screening material discharged from the crusher 10' on conveyor 36 before it is returned to conveyor 34.
  • the fines output from the crusher 10' is fed via ducting 40 to a cyclone 42 which has an output to a bagging plant for reclamation of the "fines".
  • An extraction fan and motor 44 is disposed in ducting 46 leading from the cyclone 42 for the extraction of air from the cyclone. It has been found in use of the apparatus that the air outputted from duct 46 contains a high portion of extremely fine material so for the purposes of reclaiming this material and so that it is not dispersed into the atmosphere, ducting 46 leads to one or more bag filter for collection of the extremely fine material.
  • the crusher 10' shown in Figure 3 will now be described in more detail with reference to Figures 4 to 8, primed reference numerals designating the same parts as reference numerals in Figures 1 and 2.
  • the standard details of the crusher are shown in British Patent Specification No. 1439639 and are not described in detail herein.
  • the crusher shown in Figure 4 has an input duct 48 into which feed material is fed from conveyor 34 in the direction of arrow F2'. The feed material enters the crusher and is flung outwards by rotor 13' to be crushed against a bed of material built up against the walls of the housing 12' in a crushing chamber 23'.
  • the apparatus shown in Figure 4 differs from that shown in Figure 1 in that the removable portion or lid 1' of the housing 12' is provided, as shown in Figure 5, with twelve circumferentially spaced openings 50 ( three only being shown in Figure 5). With twelve such openings 50, the angle ⁇ is 30°.
  • the larger cone 19' instead of being constructed along the dotted line in Figure 4 (as it is in Figure 1) is constructed as a cone in its upper region with upwardly extending walls 52 in its lower region which meet the lid 1' of the housing 12' at a region which is further away from the centre line of the crusher 10' than in the apparatus of Figure 1.
  • the air In the embodiment shown in Figure 1, the air must flow around a corner between the rotor 13 and the housing 12 which can create a restriction in the air flow / and turbulence. In contrast, in the embodiment shown in Figure 4, the air can flow directly upwardly from the crushing chamber 23' without such restriction.
  • This disposition of the walls 52 of the larger cone 19' of the separator in combination with the openings 50 in the lid 1' remarkably increases the upward flow of air from the crusher through the separator, and consequently the percentage output of "fines".
  • Twelve air inlets 54 are disposed in the upwardly extending wall 52 of the larger cone 19', which enable a further adjustment of the air flow to be made.
  • the flow of air through the crusher can also be controlled by adjustment of the spacing of vanes (not shown in Figure 4) in the upper region of the separator and of a thimble 56, which can move up and down between the lines x-x and y-y: with the thimble pushed down, the product becomes coarser. In this way, the particle size in the output material can be finely controlled since it is dependent on the upward air flow which varies with the volume available in the separator.
  • an inspection door 58 is provided whereby the crushing chamber 23' can be inspected.
  • the motor being used was generating 150 horse power; and the volume of air used was 14,000 cubic ft per minute (0.025 cubic metres per second), although this could be reduced to about 11,000 cubic ft per minute for a similar output.
  • Material Calcined Phosphate from West Africa.
  • Feed Size All minus 30 mm.
  • the rise in temperature of the material after one hour was 15°C, the temperature remaining stable thereafter. This rise in temperature can be an advantage, particularly where hygroscopic materials are being used.
  • the apparatus is capable of handling raw feed material which has not been previously dried. About 10% of the net output was carried forward as extremely fine material to the bag filters via ducting 46.
  • the feed material inputted to the crusher may have a bulk density of about 811b per cubic ft (0.35 kg per cubic centimetre).
  • test results are illustrative of the extremely high percentage of "fines" in the output which can be achieved from the apparatus of the present invention.
  • the apparatus accordingly has applications for use with a wide variety of materials, and is particularly useful with very abrasive materials which cannot be used economically in existing fine grinding mills.
  • an apparatus and a method in accordance with the present invention may be used to produce a "fine product" for a variety of applications.
  • the product material may comprise phosphate, potash or talc.
  • the apparatus may further be used in the field of metalliferous mining to extract a metal, such as copper, tin, silver, gold, iron, lead or zinc, from its ore.
  • the apparatus is capable of handling material of a higher moisture content than most existing equipment since the material is not forced through a gap of a predetermined size as occurs, for example, in roller path type grinding mills. In such mills, material with a high moisture content can become compacted and thus affect operation of the mill.

Landscapes

  • Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Crushing And Pulverization Processes (AREA)
  • Combined Means For Separation Of Solids (AREA)
EP84306892A 1983-10-11 1984-10-10 Appareil et méthode permettant d'obtenir un produit broyé à partir d'un matériau d'alimentation solide Withdrawn EP0140613A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB838327201A GB8327201D0 (en) 1983-10-11 1983-10-11 Obtaining comminuted product from solid feed material
GB8327201 1983-10-11

Publications (2)

Publication Number Publication Date
EP0140613A2 true EP0140613A2 (fr) 1985-05-08
EP0140613A3 EP0140613A3 (fr) 1986-04-30

Family

ID=10550022

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84306892A Withdrawn EP0140613A3 (fr) 1983-10-11 1984-10-10 Appareil et méthode permettant d'obtenir un produit broyé à partir d'un matériau d'alimentation solide

Country Status (2)

Country Link
EP (1) EP0140613A3 (fr)
GB (2) GB8327201D0 (fr)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3609229A1 (de) * 1986-03-19 1987-09-24 Krupp Polysius Ag Verfahren und anlage zur zerkleinerung von sproedem mahlgut
AU594367B2 (en) * 1985-09-17 1990-03-08 Bryan Allen Bartley Improvements in or relating to methods of mineral breaking and/or apparatus used therefor
WO1990007379A1 (fr) * 1988-12-29 1990-07-12 O&K Orenstein & Koppel Ag Procede et dispositif pour la fragmentation de materiaux en vrac
EP0426651A2 (fr) * 1989-10-30 1991-05-08 Maschinenfabrik Liezen Gesellschaft m.b.H. Procédé de broyage de matériaux en morceaux et dispositif pour sa mise en oeuvre
WO1998016316A1 (fr) * 1996-10-16 1998-04-23 Spectrasonic Disintegration Equipment Corp. Dispositif et procede de broyage
FR2936431A1 (fr) * 2008-09-26 2010-04-02 Broyeur Poittemill Ingenerie Broyeur a flux d'air comportant un systeme de guidage des particules
CN103433105A (zh) * 2013-09-04 2013-12-11 福建南方路面机械有限公司 一种冲击式破碎机及其破碎方法
CN115254310A (zh) * 2022-07-29 2022-11-01 时秀芳 一种药剂科用颗粒物碾碎装置
CN116213080A (zh) * 2023-03-06 2023-06-06 江苏大学流体机械温岭研究院 一种应用于固液两相流中固体颗粒多级破碎分离装置

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117548186B (zh) * 2024-01-12 2024-04-05 潍坊精华装备科技有限公司 一种防合格物料回流的高效分选机

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB376760A (en) * 1931-03-05 1932-07-05 Ernest Feuerheerd Improvements in or relating to apparatus for pulverising or grinding coal and other materials
US3162382A (en) * 1962-03-22 1964-12-22 Bath Iron Works Corp Centrifugal pulverizer
FR2201928A1 (fr) * 1972-10-05 1974-05-03 Mac Donald George
US3995784A (en) * 1975-03-21 1976-12-07 Consejo Nacional De Ciencia Y Tecnologia Rotary mill for micronic grinding
EP0102742A2 (fr) * 1982-07-28 1984-03-14 Barmac Associates Limited Concasseurs de minerai

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1051020A (fr) *
GB645673A (en) * 1948-10-14 1950-11-08 Ostravske Chemicke Zd Y Narodn Improvements in or relating to mills or grinders
ZA755513B (en) * 1974-08-29 1976-07-28 Pennsylvania Crusher Corp Improvements in high speed rotating crushing machinery and crushing methods

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB376760A (en) * 1931-03-05 1932-07-05 Ernest Feuerheerd Improvements in or relating to apparatus for pulverising or grinding coal and other materials
US3162382A (en) * 1962-03-22 1964-12-22 Bath Iron Works Corp Centrifugal pulverizer
FR2201928A1 (fr) * 1972-10-05 1974-05-03 Mac Donald George
US3995784A (en) * 1975-03-21 1976-12-07 Consejo Nacional De Ciencia Y Tecnologia Rotary mill for micronic grinding
EP0102742A2 (fr) * 1982-07-28 1984-03-14 Barmac Associates Limited Concasseurs de minerai

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU594367B2 (en) * 1985-09-17 1990-03-08 Bryan Allen Bartley Improvements in or relating to methods of mineral breaking and/or apparatus used therefor
US4921173A (en) * 1985-09-17 1990-05-01 Bartley Bryan A Methods of mineral breaking and apparatus used therefor
DE3609229A1 (de) * 1986-03-19 1987-09-24 Krupp Polysius Ag Verfahren und anlage zur zerkleinerung von sproedem mahlgut
WO1990007379A1 (fr) * 1988-12-29 1990-07-12 O&K Orenstein & Koppel Ag Procede et dispositif pour la fragmentation de materiaux en vrac
EP0426651A2 (fr) * 1989-10-30 1991-05-08 Maschinenfabrik Liezen Gesellschaft m.b.H. Procédé de broyage de matériaux en morceaux et dispositif pour sa mise en oeuvre
EP0426651A3 (en) * 1989-10-30 1991-11-06 Maschinenfabrik Liezen Gesellschaft M.B.H. Method for crushing lump material and device for carrying out said method
WO1998016316A1 (fr) * 1996-10-16 1998-04-23 Spectrasonic Disintegration Equipment Corp. Dispositif et procede de broyage
FR2936431A1 (fr) * 2008-09-26 2010-04-02 Broyeur Poittemill Ingenerie Broyeur a flux d'air comportant un systeme de guidage des particules
CN103433105A (zh) * 2013-09-04 2013-12-11 福建南方路面机械有限公司 一种冲击式破碎机及其破碎方法
CN103433105B (zh) * 2013-09-04 2015-09-16 福建南方路面机械有限公司 一种冲击式破碎机及其破碎方法
CN115254310A (zh) * 2022-07-29 2022-11-01 时秀芳 一种药剂科用颗粒物碾碎装置
CN116213080A (zh) * 2023-03-06 2023-06-06 江苏大学流体机械温岭研究院 一种应用于固液两相流中固体颗粒多级破碎分离装置
CN116213080B (zh) * 2023-03-06 2024-07-05 江苏大学流体机械温岭研究院 一种应用于固液两相流中固体颗粒多级破碎分离装置

Also Published As

Publication number Publication date
GB8425540D0 (en) 1984-11-14
GB8327201D0 (en) 1983-11-09
EP0140613A3 (fr) 1986-04-30
GB2147824A (en) 1985-05-22

Similar Documents

Publication Publication Date Title
US9212404B2 (en) Preparation method for stainless steel slags and steelworks slags for recovery of metal
JPH07163895A (ja) 異なる粒度の材料を破砕するための方法および装置
MX2007009130A (es) Molino de rodillos.
EP0140613A2 (fr) Appareil et méthode permettant d'obtenir un produit broyé à partir d'un matériau d'alimentation solide
JPH0538464A (ja) スラグ粉砕設備
US6042032A (en) Method and apparatus for simultaneously and continuously producing a plurality of size fractions of a mineral material
US5215262A (en) Method and apparatus for comminuting bulk materials
CN105903582A (zh) 一种保护大鳞片石墨的气流选矿装置和方法
MXPA97002608A (en) Efficient production of gypsum calcinated by collection and classification of fine and
KR100206609B1 (ko) 입자이중분리기
JP3570265B2 (ja) 粉砕装置
JPH041660B2 (fr)
US5058813A (en) Method for comminuting brittle material to be ground
JP3216677B2 (ja) 粉砕設備
Van der Meer et al. Case study of dry HPGR grinding and classification in ore processing
JP2755338B2 (ja) 粉砕設備
Giblett Grinding technologies
CN112222414A (zh) 稀散金属细粉生产设备及生产方法
JP3036669B2 (ja) 粉砕設備
JP2955389B2 (ja) 粉砕装置
CN205701118U (zh) 一种保护大鳞片石墨的气流选矿装置
JPH04281858A (ja) 粉砕装置
JPH04210257A (ja) 粉砕システム
JP2506796Y2 (ja) 予備粉砕装置
CN110869131A (zh) 两级研磨回路和借助于两级研磨工艺来生产研磨产品的方法

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

Designated state(s): AT BE CH DE FR IT LI LU NL SE

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT BE CH DE FR IT LI LU NL SE

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

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19870102

RIN1 Information on inventor provided before grant (corrected)

Inventor name: MURRAY, ALISTAIR SCOTT

Inventor name: HILL, HENRY EDWARD