WO1996006683A1 - Separator - Google Patents

Separator Download PDF

Info

Publication number
WO1996006683A1
WO1996006683A1 PCT/NO1995/000144 NO9500144W WO9606683A1 WO 1996006683 A1 WO1996006683 A1 WO 1996006683A1 NO 9500144 W NO9500144 W NO 9500144W WO 9606683 A1 WO9606683 A1 WO 9606683A1
Authority
WO
WIPO (PCT)
Prior art keywords
section
hydrocyclone
flow modifier
tapered
cyclone
Prior art date
Application number
PCT/NO1995/000144
Other languages
French (fr)
Inventor
Bjørn CHRISTIANSEN
Karl Petter LØKEN
Original Assignee
Kværner Process Systems A.S
Den Norske Stats Oljeselskap A.S
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 Kværner Process Systems A.S, Den Norske Stats Oljeselskap A.S filed Critical Kværner Process Systems A.S
Priority to EP95930742A priority Critical patent/EP0777531A1/en
Priority to AU34007/95A priority patent/AU3400795A/en
Publication of WO1996006683A1 publication Critical patent/WO1996006683A1/en

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B04CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04CAPPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
    • B04C5/00Apparatus in which the axial direction of the vortex is reversed
    • B04C5/08Vortex chamber constructions
    • B04C5/107Cores; Devices for inducing an air-core in hydrocyclones
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D17/00Separation of liquids, not provided for elsewhere, e.g. by thermal diffusion
    • B01D17/02Separation of non-miscible liquids
    • B01D17/0217Separation of non-miscible liquids by centrifugal force
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D19/00Degasification of liquids
    • B01D19/0042Degasification of liquids modifying the liquid flow
    • B01D19/0052Degasification of liquids modifying the liquid flow in rotating vessels, vessels containing movable parts or in which centrifugal movement is caused
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B04CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04CAPPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
    • B04C5/00Apparatus in which the axial direction of the vortex is reversed
    • B04C5/14Construction of the underflow ducting; Apex constructions; Discharge arrangements ; discharge through sidewall provided with a few slits or perforations
    • B04C5/181Bulkheads or central bodies in the discharge opening

Definitions

  • the invention concerns a separator device comprising a preferably hollow section having decreasing diameter from the preferably open top towards a closed bottom, or preferably attached to a straight cylindrical tube, which may be closed at the bottom and which is arranged concentrically inside a tapered section of a hydrocyclone, having preferably the same shape as the invention, for separating gas or vapour from a liquid, or alternatively two other fluids with differing densities, i.e. oil/water.
  • the invention can either be attached to the hydrocyclone walls using fixed connections such as stay rods and the like, or the device can be allowed to rotate, either by means of a motor or by arranging turbine blades at the outlet of the invention's tube section.
  • classifiers which have the objective to separate solid particles of different diameters, or different densities, from a continuous liquid- or gas fluid.
  • Classifiers represent actually an integrated two stage cyclone separator.
  • the second stage separation chamber, removing the small/light particles, might at first hand look similar to the invention described in this patent application, i.e. US patent 2,706,045, but it has a completely different function.
  • the main object of the invention is to prevent gas from being entrained in the liquid phase in cases where it is desirable to separate gas and liquid.
  • a secondary object of the device is the ability to impart the gas-free liquid phase a substantial centrifugal field in order to achieve liquid/liquid (e.g. oil/water), or liquid/particle separation.
  • fig. 1 shows a side view of a conventional hydrocyclone containing a device which is according to the invention
  • fig. 2 shows a top view example of how the upper tapered part of the device may be affixed to the hydrocyclone's outer wall
  • fig. 3 illustrates an example how the lower part of the device's tube section may be affixed to the cyclone's tapered outlet section.
  • fig. 4 shows as an example a "cup" formed shape of the device.
  • fig. 5 illustrates a practical arrangement of the invention inside a hydrocyclone for gas/liquid separation when the cyclone liquid outlet is submerged beyond a free liquid surface, i.e. cyclone used as an inlet device inside gravity separators.
  • fig. 6 illustrates another practical arrangement of the invention inside a hydrocyclone for gas/liquid- or liquid/liquid separation where the cyclone body diameter is reduced in two or more sections.
  • the invention is used inside the last tapered section of the cyclone.
  • a "tapered" section means a section decreasing from a large diameter towards a smaller diameter.
  • the shape of the tapered section can be conically, as shown in Fig. 1, or any suitable shape, e.g. as illustrated in Fig. 4.
  • the preferably conically shaped annulus in Fig. 1 (can also have other shapes such as shown in fig. 4) which is formed by the tapered cyclone inner wall 5 and the tapered section of the device 6 will create a back pressure in the flow and thus build up a pressure in the center of the separation chamber 1 allowing the lighter phase (i.e. the gas) to be forced through the vortex finder 4.
  • This backpressure is developed according to the nature law of maintaing rotational momentum.
  • the tangential component of the flow will increase substantially due to the decrease in cross-sectional diameter.
  • the pressure from cross sections A-A to B-B will then decrease proportionally in order to maintain the total energy of the separated denser phase.
  • Fig. 1 shows the highest reccomended axial location of the device 6 where the inlet of the device 6 is at the same axial height as the start of the cyclone's tapered section 5.
  • the lowest reccomended location is determined by the cross- sectional inlet area of the formed annulus, which should preferably be larger than the cross-sectional area of the lower outlet pipe 10 of the cyclone.
  • the tapered inlet section 6 of the device should have a diameter greater than 0.9X the diameter of the cyclone's lower outlet pipe 10, and smaller than 0.99X the diameter of the cylindrical section 1 of the cyclone.
  • a conical section 6 is a preferred geometry of the device, it should be noted that it might have any shape when it is decreased from a large diameter to a smaller diameter.
  • Fig. 5 shows a cup shaped geometry as an example.
  • the preferred attached tube 7 shown in fig. 1 can be removed.
  • Fig. 1 illustrates a hydrocyclone consisting of a cylindrical section 1, a tangential inlet 2, a circular top plate 3 with a through-going pipe 4 for extraction of the gas phase, a section 5 where the cyclone body diameter is decreased from a large diameter to a smaller diameter and preferably a discharge pipe 10 for extraction of the liquid phase.
  • the invention comprises a device which is attached inside the cyclone's tapered section 5 consisting of a tapered section 6, having preferably a conical shape, which might be closed at the bottom or attached to a tube 7.
  • the top of the tapered section 6 should preferably be open, but can be closed with a cylindrical plane plate as well.
  • Fig. 1 illustrates how the invention is attached by stay rods 8 and 9 in a standard hydrocyclone.
  • Fig. 2 illustrates how the invention's tapered section 6 is attached to the hydrocy clone's tapered section 5 with stay rods 8.
  • Fig. 3 illustrates how the invention's tube section 7 is attached to the hydro- cyclone's outlet pipe 10 by stay rods 9.
  • Fig. 4 shows as an example a "cup" formed shape of the device.
  • Fig. 5 illustrates a practical arrangement of the invention inside a hydrocyclone for gas/liquid separation when the cyclone liquid outlet is submerged beyond a free liquid surface 1 1, i.e. the cyclone being used as an inlet device inside gravity separators.
  • Fig. 6 illustrates another practical arrangement of the invention inside a hydrocyclone for gas/liquid- or liquid/liquid separation where the cyclone body diameter is reduced in two or more sections.
  • the invention is used preferably inside the last tapered section of the cyclone.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Cyclones (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
  • Refuse Collection And Transfer (AREA)

Abstract

In order to prevent gas from being involved in the liquid phase in a separator in the form of a hydrocyclone, a device is used with a tapered inlet section (6), which can be hollow or blocked with a cylindrical plain plate, which is attached to a straight, cylindrical tube (7) which can be plugged, or is run out through the cyclone's side walls or bottom.

Description

Separator
The invention concerns a separator device comprising a preferably hollow section having decreasing diameter from the preferably open top towards a closed bottom, or preferably attached to a straight cylindrical tube, which may be closed at the bottom and which is arranged concentrically inside a tapered section of a hydrocyclone, having preferably the same shape as the invention, for separating gas or vapour from a liquid, or alternatively two other fluids with differing densities, i.e. oil/water. The invention can either be attached to the hydrocyclone walls using fixed connections such as stay rods and the like, or the device can be allowed to rotate, either by means of a motor or by arranging turbine blades at the outlet of the invention's tube section.
The device should not be confused with conventional core stabilizors which are placed at the centre of the cyclone's lower outlet cross section, e.g. described in US patent 2,757,581. These usually consist of a solid cylindrical object with a diameter which is much smaller than the diameter of the lower outlet cross section.
Furthermore, the device should not be confused with "classifiers" which have the objective to separate solid particles of different diameters, or different densities, from a continuous liquid- or gas fluid. "Classifiers" represent actually an integrated two stage cyclone separator. The second stage separation chamber, removing the small/light particles, might at first hand look similar to the invention described in this patent application, i.e. US patent 2,706,045, but it has a completely different function.
Finally, the device must not be confused with "dollar plates" which are used for gas scrubber cyclones, utilized to separate small fractions of liquid (< 5 vol%) from a continuous gas phase. These usually consist of a circular plate arranged in the lower end of a cylindrical separator vessel. Their function is to prevent the up-flowing gas vortex from re-entraining already separated liquid from the lϊee liquid surface formed in the bottom of the vessel. A physical analogue situation is the cyclone tornado which is capable of "sucking" large objects like houses up into the air.
The main object of the invention is to prevent gas from being entrained in the liquid phase in cases where it is desirable to separate gas and liquid. A secondary object of the device is the ability to impart the gas-free liquid phase a substantial centrifugal field in order to achieve liquid/liquid (e.g. oil/water), or liquid/particle separation.
The invention is described with reference to the drawings, in which:
fig. 1 shows a side view of a conventional hydrocyclone containing a device which is according to the invention,
fig. 2 shows a top view example of how the upper tapered part of the device may be affixed to the hydrocyclone's outer wall, and
fig. 3 illustrates an example how the lower part of the device's tube section may be affixed to the cyclone's tapered outlet section.
fig. 4 shows as an example a "cup" formed shape of the device.
fig. 5 illustrates a practical arrangement of the invention inside a hydrocyclone for gas/liquid separation when the cyclone liquid outlet is submerged beyond a free liquid surface, i.e. cyclone used as an inlet device inside gravity separators.
fig. 6 illustrates another practical arrangement of the invention inside a hydrocyclone for gas/liquid- or liquid/liquid separation where the cyclone body diameter is reduced in two or more sections. The invention is used inside the last tapered section of the cyclone.
In the following description a "tapered" section means a section decreasing from a large diameter towards a smaller diameter. The shape of the tapered section can be conically, as shown in Fig. 1, or any suitable shape, e.g. as illustrated in Fig. 4.
The working principle for the separator device is described in the following:
The preferably conically shaped annulus in Fig. 1 (can also have other shapes such as shown in fig. 4) which is formed by the tapered cyclone inner wall 5 and the tapered section of the device 6 will create a back pressure in the flow and thus build up a pressure in the center of the separation chamber 1 allowing the lighter phase (i.e. the gas) to be forced through the vortex finder 4. This backpressure is developed according to the nature law of maintaing rotational momentum. When moving from the cross section A-A to B-B in fig 1, the tangential component of the flow will increase substantially due to the decrease in cross-sectional diameter. The pressure from cross sections A-A to B-B will then decrease proportionally in order to maintain the total energy of the separated denser phase.
The tapered inlet section of the device 6 must thus be arranged in the cyclone's tapered section 5 in order to achieve this effect. Fig. 1 shows the highest reccomended axial location of the device 6 where the inlet of the device 6 is at the same axial height as the start of the cyclone's tapered section 5. The lowest reccomended location is determined by the cross- sectional inlet area of the formed annulus, which should preferably be larger than the cross-sectional area of the lower outlet pipe 10 of the cyclone. The tapered inlet section 6 of the device should have a diameter greater than 0.9X the diameter of the cyclone's lower outlet pipe 10, and smaller than 0.99X the diameter of the cylindrical section 1 of the cyclone.
Although a conical section 6 is a preferred geometry of the device, it should be noted that it might have any shape when it is decreased from a large diameter to a smaller diameter. Fig. 5 shows a cup shaped geometry as an example. Furthermore, the preferred attached tube 7 shown in fig. 1 can be removed.
One embodiment of the invention is now described in detail with reference to the drawings:
Fig. 1 illustrates a hydrocyclone consisting of a cylindrical section 1, a tangential inlet 2, a circular top plate 3 with a through-going pipe 4 for extraction of the gas phase, a section 5 where the cyclone body diameter is decreased from a large diameter to a smaller diameter and preferably a discharge pipe 10 for extraction of the liquid phase. These parts are considered to be according to the prior art. The invention comprises a device which is attached inside the cyclone's tapered section 5 consisting of a tapered section 6, having preferably a conical shape, which might be closed at the bottom or attached to a tube 7. The top of the tapered section 6 should preferably be open, but can be closed with a cylindrical plane plate as well. The optional tube 7 can be plugged at the lower end or it can be run out of the hydrocyclone through side walls or the bottom. There are various ways of attaching the device to the hydrocyclone. Fig. 1 illustrates how the invention is attached by stay rods 8 and 9 in a standard hydrocyclone.
Fig. 2 illustrates how the invention's tapered section 6 is attached to the hydrocy clone's tapered section 5 with stay rods 8.
Fig. 3 illustrates how the invention's tube section 7 is attached to the hydro- cyclone's outlet pipe 10 by stay rods 9.
Fig. 4 shows as an example a "cup" formed shape of the device.
Fig. 5 illustrates a practical arrangement of the invention inside a hydrocyclone for gas/liquid separation when the cyclone liquid outlet is submerged beyond a free liquid surface 1 1, i.e. the cyclone being used as an inlet device inside gravity separators.
Fig. 6 illustrates another practical arrangement of the invention inside a hydrocyclone for gas/liquid- or liquid/liquid separation where the cyclone body diameter is reduced in two or more sections. The invention is used preferably inside the last tapered section of the cyclone.

Claims

PATENT CLAIMS
1. A gas-/liquid separator in the form of a hydrocyclone, characterized in that in the tapered section of the hydrocyclone there is placed a device comprising a hollow section with decreasing diameter from the top, which preferably is open, towards the bottom, which preferably is closed.
2. A gas-/liquid separator of claim 1, characterized in that the bottom of the device is open and attached to a straight cylindrical tube, which can be plugged at the bottom, or is run out through the cyclone's side walls or bottom.
3. A gas-/liquid separator of claim 1 , characterized in that the device in the tapered section of the hydrocyclone is closed at the top and closed at the bottom.
4. A gas-/liquid separator of claim 1, characterized in that the device either is attached to the hydrocyclone through fixed connections such as stay rods and the like, or that the device is rotatable by means of bearings which are attached to the cyclone through fixed connections such as stay rods and the like, the rotary energy either being supplied by means of a motor or by arranging turbine blades at the outlet of the device's pipe section.
5. A gas-/liquid separator of claim 1, characterized in that the cyclone body diameter is reduced in two or more sections, and the device is used preferably inside the last tapered section of the cyclone.
AMENDED CLAIMS
[received by the International Bureau on 5 February 1996 (05.02.96); original claims 1-5 replaced by new claims 1-7 (1 page)]
1. A flow modifier for a hydrocyclone for separating a first fluid from a second fluid, the density of the first fluid being greater than the density of the second fluid, the flow modifier having a cross-section arranged, when in use, to increase the rotational momentum of the first fluid within a tapered section of the hydrocyclone so as to increase the pressure within a core of the hydrocyclone, and thereby increase the flow of the core to an overflow.
2. A flow modifier as claimed in claim 1, wherein the hydrocyclone has a cylindrical section and an outlet section, and the flow modifier has a first end having a first diameter less than 99% of the diameter of the cylindrical section and greater than 90% of the minimum diameter of the outlet section
3. A flow modifier as claimed in claim 1, wherein the cross-section of the flow modifier is tapered.
4. A flow modifier as claimed in claim 1, wherein the cross-section of the flow modifier is substantially funnel-shaped.
5. A flow modifier as claimed in claim 1, wherein the second end of the flow modifier is closed so as to form an open cavity.
6. A flow modifier as claimed in claim 3, wherein the flow modifier is axially located substantially between the axial ends of the tapered section of the hydrocyclone.
7. A flow modifier as claimed in claim 4, wherein the tapered portion of the flow modifier is axially located substantially between the axial ends of the tapered section of the hydrocyclone.
PCT/NO1995/000144 1994-08-31 1995-08-30 Separator WO1996006683A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP95930742A EP0777531A1 (en) 1994-08-31 1995-08-30 Separator
AU34007/95A AU3400795A (en) 1994-08-31 1995-08-30 Separator

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NO943226 1994-08-31
NO943226A NO180258C (en) 1994-08-31 1994-08-31 Device by separator

Publications (1)

Publication Number Publication Date
WO1996006683A1 true WO1996006683A1 (en) 1996-03-07

Family

ID=19897359

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/NO1995/000144 WO1996006683A1 (en) 1994-08-31 1995-08-30 Separator

Country Status (5)

Country Link
EP (1) EP0777531A1 (en)
AU (1) AU3400795A (en)
CA (1) CA2198697A1 (en)
NO (1) NO180258C (en)
WO (1) WO1996006683A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012019624A1 (en) * 2010-08-11 2012-02-16 Fmc Technologies C.V. High efficiency phase splitter
CN112691798A (en) * 2019-10-22 2021-04-23 中国石油化工股份有限公司 Cyclone separator, application method thereof and fluidized bed reactor
JP6948742B1 (en) * 2021-05-13 2021-10-13 株式会社Ambitious Technologies Aggregate cyclone device, marine plastic removal system using it, ship equipped with the system, and operation method of the ship

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU2012211392B2 (en) 2011-08-29 2014-11-20 Process Group Pty Ltd Compact Separation Apparatus

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2706045A (en) * 1955-04-12 Liquid separation
EP0346747A2 (en) * 1988-06-15 1989-12-20 Dozent Doppelzyklon- Entstaubungsanlagen Gmbh Cyclone separator
US5045218A (en) * 1986-11-26 1991-09-03 Delawood Pty. Ltd. Method of separating a lighter dispersed fluid from a denser liquid in a hydrocyclone having flow-modifying means
US5071542A (en) * 1989-06-01 1991-12-10 Tuszko Wlodzimierz J Anti-suction cyclone separation method and apparatus
EP0468426A2 (en) * 1990-07-23 1992-01-29 Kubota Corporation Classifier for powdery material

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2706045A (en) * 1955-04-12 Liquid separation
US5045218A (en) * 1986-11-26 1991-09-03 Delawood Pty. Ltd. Method of separating a lighter dispersed fluid from a denser liquid in a hydrocyclone having flow-modifying means
EP0346747A2 (en) * 1988-06-15 1989-12-20 Dozent Doppelzyklon- Entstaubungsanlagen Gmbh Cyclone separator
US5071542A (en) * 1989-06-01 1991-12-10 Tuszko Wlodzimierz J Anti-suction cyclone separation method and apparatus
EP0468426A2 (en) * 1990-07-23 1992-01-29 Kubota Corporation Classifier for powdery material

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
DERWENT'S ABSTRACT, No. 83-787860/41, Week 8341; & SU,A,980 851 (GORKI POLY), 15 December 1982. *

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012019624A1 (en) * 2010-08-11 2012-02-16 Fmc Technologies C.V. High efficiency phase splitter
CN103124587A (en) * 2010-08-11 2013-05-29 Fmc科技有限合伙公司 High efficiency phase splitter
AU2010358909B2 (en) * 2010-08-11 2015-05-07 Fmc Separation Systems, Bv High efficiency phase splitter
CN103124587B (en) * 2010-08-11 2015-09-02 Fmc科技有限合伙公司 High efficiency phase splitter
US9687757B2 (en) 2010-08-11 2017-06-27 Fmc Separation Systems, Bv High efficiency phase splitter
EP3505227A1 (en) * 2010-08-11 2019-07-03 FMC Separation Systems, BV High efficiency phase splitter
CN112691798A (en) * 2019-10-22 2021-04-23 中国石油化工股份有限公司 Cyclone separator, application method thereof and fluidized bed reactor
CN112691798B (en) * 2019-10-22 2022-11-15 中国石油化工股份有限公司 Cyclone separator, application method thereof and fluidized bed reactor
JP6948742B1 (en) * 2021-05-13 2021-10-13 株式会社Ambitious Technologies Aggregate cyclone device, marine plastic removal system using it, ship equipped with the system, and operation method of the ship
WO2022239298A1 (en) * 2021-05-13 2022-11-17 株式会社Ambitious Technologies Flocculation cyclone device, marine plastic removal system using flocculation cyclone device, ship provided with marine plastic removal system using flocculation cyclone device, and operation method for ship provided with marine plastic removal system using flocculation cyclone device

Also Published As

Publication number Publication date
NO180258B (en) 1996-12-09
NO943226L (en) 1996-03-01
AU3400795A (en) 1996-03-22
NO943226D0 (en) 1994-08-31
CA2198697A1 (en) 1996-03-07
NO180258C (en) 1997-03-19
EP0777531A1 (en) 1997-06-11

Similar Documents

Publication Publication Date Title
US3235090A (en) Hydroclones
JP4598060B2 (en) Cyclone separator
CA2687349C (en) Induced vortex particle separator
US3898068A (en) Cyclonic separator
US6596046B2 (en) Cyclone separator having a variable longitudinal profile
US6398973B1 (en) Cyclone separator
JP4359975B2 (en) Solid separation device
US6129775A (en) Terminal insert for a cyclone separator
US6419719B2 (en) Cyclonic vacuum cleaner
JP4955387B2 (en) Cyclone separator
AU2005321254B2 (en) Cyclonic separator and method for degassing a fluid mixture
US6168716B1 (en) Cyclone separator having a variable transverse profile
US6890375B2 (en) Cyclonic air filter with exit baffle
US2672215A (en) Cyclone separator for separating solid particles from gases
WO1997046323A1 (en) Cyclonic separator
US3807142A (en) Method and apparatus for high efficiency removal of gases and particles from paper pulp suspensions and other fluids
JPS6318447Y2 (en)
US3433362A (en) Cyclone purifier
KR101137102B1 (en) Cyclon Separator
WO1996006683A1 (en) Separator
EP1180400A1 (en) Cyclone separation apparatus
JP2009090268A (en) Cyclone type filter device
CN212640032U (en) High-efficient oil removal degritting separator
RU211920U1 (en) SEPARATOR
US9861913B2 (en) Centrifugal separator

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AM AT AU BB BG BR BY CA CH CN CZ DE DK EE ES FI GB GE HU IS JP KE KG KP KR KZ LK LR LT LU LV MD MG MN MW MX NO NZ PL PT RO RU SD SE SG SI SK TJ TM TT UA UG US UZ VN

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): KE MW SD SZ UG AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML MR NE SN TD TG

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 1995930742

Country of ref document: EP

ENP Entry into the national phase

Ref document number: 2198697

Country of ref document: CA

Ref country code: CA

Ref document number: 2198697

Kind code of ref document: A

Format of ref document f/p: F

WWP Wipo information: published in national office

Ref document number: 1995930742

Country of ref document: EP

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

ENP Entry into the national phase

Ref country code: US

Ref document number: 1997 793681

Date of ref document: 19970623

Kind code of ref document: A

Format of ref document f/p: F

WWW Wipo information: withdrawn in national office

Ref document number: 1995930742

Country of ref document: EP