HK27686A - Stirring equipment for the dispersion of gas during the treatment of metal baths - Google Patents

Stirring equipment for the dispersion of gas during the treatment of metal baths

Info

Publication number
HK27686A
HK27686A HK276/86A HK27686A HK27686A HK 27686 A HK27686 A HK 27686A HK 276/86 A HK276/86 A HK 276/86A HK 27686 A HK27686 A HK 27686A HK 27686 A HK27686 A HK 27686A
Authority
HK
Hong Kong
Prior art keywords
bath
treatment
dispersion
gas during
stirring equipment
Prior art date
Application number
HK276/86A
Other languages
English (en)
Inventor
Jacques Gimond
Richard Gonda
Jean-Marie Hicter
Pierre Laty
Original Assignee
Pechiney Aluminium
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 Pechiney Aluminium filed Critical Pechiney Aluminium
Publication of HK27686A publication Critical patent/HK27686A/xx

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22DCASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D1/00Treatment of fused masses in the ladle or the supply runners before casting
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22BPRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B9/00General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
    • C22B9/05Refining by treating with gases, e.g. gas flushing also refining by means of a material generating gas in situ
    • C22B9/055Refining by treating with gases, e.g. gas flushing also refining by means of a material generating gas in situ while the metal is circulating, e.g. combined with filtration
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/20Mixing gases with liquids
    • B01F23/23Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
    • B01F23/233Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using driven stirrers with completely immersed stirring elements
    • B01F23/2331Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using driven stirrers with completely immersed stirring elements characterised by the introduction of the gas along the axis of the stirrer or along the stirrer elements
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/20Mixing gases with liquids
    • B01F23/23Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
    • B01F23/233Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using driven stirrers with completely immersed stirring elements
    • B01F23/2331Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using driven stirrers with completely immersed stirring elements characterised by the introduction of the gas along the axis of the stirrer or along the stirrer elements
    • B01F23/23314Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using driven stirrers with completely immersed stirring elements characterised by the introduction of the gas along the axis of the stirrer or along the stirrer elements through a hollow stirrer element
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F27/00Mixers with rotary stirring devices in fixed receptacles; Kneaders
    • B01F27/05Stirrers
    • B01F27/11Stirrers characterised by the configuration of the stirrers
    • B01F27/111Centrifugal stirrers, i.e. stirrers with radial outlets; Stirrers of the turbine type, e.g. with means to guide the flow
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F27/00Mixers with rotary stirring devices in fixed receptacles; Kneaders
    • B01F27/80Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis
    • B01F27/81Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis the stirrers having central axial inflow and substantially radial outflow
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22BPRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B21/00Obtaining aluminium
    • C22B21/06Obtaining aluminium refining
    • C22B21/066Treatment of circulating aluminium, e.g. by filtration
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22BPRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B9/00General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27FURNACES; KILNS; OVENS; RETORTS
    • F27DDETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D27/00Stirring devices for molten material
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/20Mixing gases with liquids
    • B01F23/23Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
    • B01F23/233Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using driven stirrers with completely immersed stirring elements
    • B01F23/2331Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using driven stirrers with completely immersed stirring elements characterised by the introduction of the gas along the axis of the stirrer or along the stirrer elements
    • B01F23/23311Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using driven stirrers with completely immersed stirring elements characterised by the introduction of the gas along the axis of the stirrer or along the stirrer elements through a hollow stirrer axis
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/20Mixing gases with liquids
    • B01F23/23Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
    • B01F23/233Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using driven stirrers with completely immersed stirring elements
    • B01F23/2335Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using driven stirrers with completely immersed stirring elements characterised by the direction of introduction of the gas relative to the stirrer
    • B01F23/23352Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using driven stirrers with completely immersed stirring elements characterised by the direction of introduction of the gas relative to the stirrer the gas moving perpendicular to the axis of rotation
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F27/00Mixers with rotary stirring devices in fixed receptacles; Kneaders
    • B01F27/05Stirrers
    • B01F27/11Stirrers characterised by the configuration of the stirrers
    • B01F27/115Stirrers characterised by the configuration of the stirrers comprising discs or disc-like elements essentially perpendicular to the stirrer shaft axis

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • General Engineering & Computer Science (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Treating Waste Gases (AREA)
  • Mixers Of The Rotary Stirring Type (AREA)
  • Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)
  • Treatment Of Steel In Its Molten State (AREA)
  • Coating Apparatus (AREA)
  • Devices And Processes Conducted In The Presence Of Fluids And Solid Particles (AREA)
  • Radiation-Therapy Devices (AREA)
  • Respiratory Apparatuses And Protective Means (AREA)
  • Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
  • Chemically Coating (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)
  • Silicates, Zeolites, And Molecular Sieves (AREA)
  • Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)
HK276/86A 1981-08-28 1986-04-17 Stirring equipment for the dispersion of gas during the treatment of metal baths HK27686A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR8116735A FR2512067B1 (fr) 1981-08-28 1981-08-28 Dispositif rotatif de dispersion de gaz pour le traitement d'un bain de metal liquide

Publications (1)

Publication Number Publication Date
HK27686A true HK27686A (en) 1986-04-25

Family

ID=9261862

Family Applications (1)

Application Number Title Priority Date Filing Date
HK276/86A HK27686A (en) 1981-08-28 1986-04-17 Stirring equipment for the dispersion of gas during the treatment of metal baths

Country Status (28)

Country Link
US (1) US4426068A (ja)
EP (1) EP0073729B1 (ja)
JP (1) JPS6049700B2 (ja)
KR (1) KR870000508B1 (ja)
AT (1) ATE12311T1 (ja)
AU (1) AU546831B2 (ja)
BG (1) BG41825A3 (ja)
BR (1) BR8205026A (ja)
CA (1) CA1184381A (ja)
CS (1) CS229943B2 (ja)
DD (1) DD202453A5 (ja)
DE (1) DE3262681D1 (ja)
DK (1) DK158325C (ja)
EG (1) EG15395A (ja)
ES (1) ES515297A0 (ja)
FR (1) FR2512067B1 (ja)
GR (1) GR77611B (ja)
HK (1) HK27686A (ja)
HU (1) HU186110B (ja)
IE (1) IE53805B1 (ja)
IN (1) IN156351B (ja)
NO (1) NO160527C (ja)
PL (1) PL131793B1 (ja)
RO (1) RO85137B (ja)
SU (1) SU1233807A3 (ja)
TR (1) TR21856A (ja)
YU (1) YU42045B (ja)
ZA (1) ZA826254B (ja)

Families Citing this family (49)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NO155447C (no) * 1984-01-25 1987-04-01 Ardal Og Sunndal Verk Anordning ved anlegg for behandling av en vaeske, f.eks. en aluminiumssmelte.
FR2562449B1 (fr) * 1984-04-06 1986-11-14 Servimetal Dispositif de traitement de l'acier, avant coulee continue, par injection de gaz
FR2568267B1 (fr) * 1984-07-27 1987-01-23 Pechiney Aluminium Poche de chloruration d'alliages d'aluminium destinee a eliminer le magnesium
DE3564449D1 (en) * 1984-11-29 1988-09-22 Foseco Int Rotary device, apparatus and method for treating molten metal
JPS62205235A (ja) * 1986-03-05 1987-09-09 Showa Alum Corp 溶融金属の処理装置
FR2604099B1 (fr) * 1986-09-22 1989-09-15 Pechiney Aluminium Dispositif rotatif a pels de mise en solution d'elements d'alliage et de dispersion de gaz dans un bain d'aluminium
JPH01271059A (ja) * 1988-04-21 1989-10-30 Honda Kinzoku Gijutsu Kk 金属連続溶解保持炉
CA1305609C (en) * 1988-06-14 1992-07-28 Peter D. Waite Treatment of molten light metals
US4954167A (en) * 1988-07-22 1990-09-04 Cooper Paul V Dispersing gas into molten metal
DE3827659A1 (de) * 1988-08-16 1990-03-15 Gabor Klaus Dieter Dipl Ing Verfahren zur physikalischen aufbereitung von medien - fluessiger bis duennbreiiger konsistenz - zur veraenderung physikalischer grundeigenschaften und aufbereitungsgeraet zur durchfuehrung des verfahrens
US5013490A (en) * 1988-10-21 1991-05-07 Showa Aluminum Corporation Device for releasing and diffusing bubbles into liquid
FR2645456B1 (fr) * 1989-04-11 1994-02-11 Air Liquide Procede et installation de traitement d'un liquide avec un gaz
FR2656001A1 (fr) * 1989-12-18 1991-06-21 Pechiney Recherche Procede et dispositif d'elaboration de produits composites a matrice metallique.
US5160693A (en) * 1991-09-26 1992-11-03 Eckert Charles E Impeller for treating molten metals
GB2294209B (en) * 1991-09-26 1996-07-03 Charles Edward Eckert Method for treating a molten metal with a gas
JPH07122106B2 (ja) * 1991-12-02 1995-12-25 福岡アルミ工業株式会社 溶融軽金属の精製処理方法及び軽金属鋳塊または鋳物の製造方法
US5634770A (en) * 1992-06-12 1997-06-03 Metaullics Systems Co., L.P. Molten metal pump with vaned impeller
CA2097648C (en) * 1992-06-12 1998-04-28 Ronald E. Gilbert Molton metal pump with vaned impeller and flow directing pumping chamber
FR2702159B1 (fr) * 1993-03-05 1995-04-28 Raymond Berchotteau Appareil pour introduire et diffuser de l'air ou un gaz dans un liquide.
NO950173L (no) * 1994-01-27 1995-07-28 Praxair Technology Inc Slagresistent oksydasjonsbeskyttelse for grafittdeler
US5527381A (en) * 1994-02-04 1996-06-18 Alcan International Limited Gas treatment of molten metals
US5660614A (en) * 1994-02-04 1997-08-26 Alcan International Limited Gas treatment of molten metals
US5597289A (en) * 1995-03-07 1997-01-28 Thut; Bruno H. Dynamically balanced pump impeller
US5660766A (en) * 1995-09-22 1997-08-26 Van Dyek; Bernhard Aerator
DE19539621C1 (de) * 1995-10-16 1997-06-05 Bayer Ag Begasungsrührer für Leichtmetallschmelzen
CA2251230C (fr) * 1996-08-02 2002-07-09 Pierre Le Brun Dispositif rotatif de dispersion de gaz pour le traitement d'un bain d'aluminium liquide
US6254340B1 (en) * 1997-04-23 2001-07-03 Metaullics Systems Co., L.P. Molten metal impeller
FR2763079B1 (fr) * 1997-05-07 1999-07-30 Graphitech Rotor et installation pour le traitement d'un bain de metal liquide
US6019576A (en) * 1997-09-22 2000-02-01 Thut; Bruno H. Pumps for pumping molten metal with a stirring action
US6056803A (en) * 1997-12-24 2000-05-02 Alcan International Limited Injector for gas treatment of molten metals
US6109449A (en) * 1998-11-04 2000-08-29 General Signal Corporation Mixing system for separation of materials by flotation
US6199836B1 (en) 1998-11-24 2001-03-13 Blasch Precision Ceramics, Inc. Monolithic ceramic gas diffuser for injecting gas into a molten metal bath
US6457940B1 (en) 1999-07-23 2002-10-01 Dale T. Lehman Molten metal pump
CA2717264C (en) * 2000-02-01 2014-04-29 Pyrotek, Inc. Pump for molten materials with suspended solids
GB2365513A (en) * 2000-08-04 2002-02-20 Pyrotek Engineering Materials Refractory components for use in metal producing processes
US6524066B2 (en) * 2001-01-31 2003-02-25 Bruno H. Thut Impeller for molten metal pump with reduced clogging
CN100409931C (zh) * 2003-11-11 2008-08-13 福州华镁新技术开发有限公司 镁合金液搅拌精炼器
BRMU8402794U8 (pt) * 2004-08-27 2021-10-26 Magnesita Insider Refratarios Ltda Configuração aplicada a dispositivo para injeção de gás e/ou gás e pós em metais líquidos através de lança refratária rotativa
CA2528757A1 (en) * 2004-12-02 2006-06-02 Bruno H. Thut Gas mixing and dispersement in pumps for pumping molten metal
US7497988B2 (en) * 2005-01-27 2009-03-03 Thut Bruno H Vortexer apparatus
US7507365B2 (en) * 2005-03-07 2009-03-24 Thut Bruno H Multi functional pump for pumping molten metal
US7534284B2 (en) * 2007-03-27 2009-05-19 Bruno Thut Flux injection with pump for pumping molten metal
KR101036321B1 (ko) * 2008-12-26 2011-05-23 주식회사 포스코 페로망간 탈린 장치 및 탈린 방법
US9259780B2 (en) 2013-03-15 2016-02-16 Esm Group Inc. Rotational lance drive and rotational lance injection method
JP6317604B2 (ja) * 2014-03-20 2018-04-25 東京窯業株式会社 気泡の放出分散装置
CA2928650C (en) 2015-05-01 2023-09-26 Opta Minerals Inc. Lance drive system
US11066713B2 (en) * 2015-12-09 2021-07-20 Tenova South Africa (Pty) Ltd Method of operating a top submerged lance furnace
CN109351141A (zh) * 2018-10-25 2019-02-19 南京安伦化工科技有限公司 一种旋转式废气净化处理装置
CN111102850B (zh) * 2019-12-26 2021-07-30 河北工业职业技术学院 金属冶炼用自动匀料器

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3227547A (en) * 1961-11-24 1966-01-04 Union Carbide Corp Degassing molten metals
SE307627B (ja) * 1967-02-09 1969-01-13 J Oestberg
DE1758186A1 (de) * 1968-04-19 1971-01-14 Dr Heinrich Willter Verfahren und Vorrichtung zur Herstellung dispersionsgeharteter Legierungen aus der Schmelze
US3743263A (en) * 1971-12-27 1973-07-03 Union Carbide Corp Apparatus for refining molten aluminum
LU64926A1 (ja) * 1972-03-08 1973-09-12
GB1428146A (en) * 1972-09-18 1976-03-17 Aluminum Co Of America Purification of aluminium
CH583781A5 (ja) * 1972-12-07 1977-01-14 Feichtinger Heinrich Sen
DE2329807C2 (de) * 1973-06-12 1975-05-15 Kobe Steel, Ltd., Kobe (Japan) Verfahren zur Bewegung einer Metallschmelze und Vorrichtung dazu
DE7622931U1 (de) * 1976-07-21 1976-12-02 Oestberg, Jan-Erik, Bettna (Schweden) Rotierender ruehrer fuer metallurgische zwecke
DE2728173A1 (de) * 1977-06-23 1979-01-04 Rudolf Koppatz Ruehrwerk fuer metallschmelzen

Also Published As

Publication number Publication date
GR77611B (ja) 1984-09-25
AU8779382A (en) 1983-03-03
FR2512067A1 (fr) 1983-03-04
CS229943B2 (en) 1984-07-16
ZA826254B (en) 1983-10-26
AU546831B2 (en) 1985-09-19
PL131793B1 (en) 1985-01-31
DK384082A (da) 1983-03-01
TR21856A (tr) 1985-10-01
ES8307914A1 (es) 1983-07-01
DD202453A5 (de) 1983-09-14
BR8205026A (pt) 1983-08-09
EG15395A (en) 1989-01-30
NO160527B (no) 1989-01-16
PL238022A1 (en) 1983-04-11
JPS6049700B2 (ja) 1985-11-05
US4426068A (en) 1984-01-17
ES515297A0 (es) 1983-07-01
IN156351B (ja) 1985-06-29
RO85137A (ro) 1984-11-25
JPS5842734A (ja) 1983-03-12
HU186110B (en) 1985-06-28
KR870000508B1 (ko) 1987-03-13
RO85137B (ro) 1984-11-30
DE3262681D1 (en) 1985-04-25
NO822913L (no) 1983-03-01
BG41825A3 (en) 1987-08-14
EP0073729A1 (fr) 1983-03-09
NO160527C (no) 1989-04-26
FR2512067B1 (fr) 1986-02-07
DK158325C (da) 1990-10-01
YU42045B (en) 1988-04-30
DK158325B (da) 1990-04-30
ATE12311T1 (de) 1985-04-15
CA1184381A (fr) 1985-03-26
IE53805B1 (en) 1989-03-01
KR840000920A (ko) 1984-03-26
EP0073729B1 (fr) 1985-03-20
YU192982A (en) 1985-03-20
SU1233807A3 (ru) 1986-05-23
IE822077L (en) 1983-02-28

Similar Documents

Publication Publication Date Title
DE3262681D1 (en) Stirring equipment for the dispersion of gas during the treatment of metal baths
EP0218989A3 (en) Method for suspending solid lubricants
JPS5583560A (en) Abrasion method
DE69007921D1 (de) Begasungsvorrichtung für ein stationäres Aluminium-Schmelzbad mit grosser Oberfläche.
DE3500573A1 (de) Verfahren und vorrichtung zum entgiften oxidierbarer stoffe, insbesondere zur mineralisierung von rueckstaenden aus der produktion von herbiziden oder insektiziden, wie dioxin o.dgl.
JPS57200759A (en) Wiper motor shaft with thread type double worm and the production method
GB1515103A (en) Process and apparatus for intermixing liquids
JPS5233288A (en) Propeller propulsion apparatus with rudder
GB907063A (en) Improvements in or relating to liquid mixing apparatus
JPS5449655A (en) Cooling apparatus
SU1473170A1 (ru) Смеситель
GB905610A (en) Improvements in or relating to rotary apparatus
JPS5413468A (en) Gas/liquid contacting method
JPS6438104A (en) Deemulsification of oil in water type emulsion
HUT38557A (en) Mixing method and mixer for intensifying the effectiveness of technological processes
JPS5698500A (en) Surface treatment equipment
JPS5562178A (en) Coloring method for surface of iron or iron alloy
JPS5250341A (en) Method and apparatus for thick coating of inner surfaces of pipes
Liu Influence of Widmanstatten Structure on the Mechanical Properties of Hypoeutectoid Steels
JPS5430236A (en) Coating device for electrodeposition
JPS5410575A (en) Apparatus for feeding finishing agent or the like
JPS6484803A (en) Paste state fluid filling method and equipment
GB1016129A (en) Improvements in and relating to apparatus for intimately mixing materials
JPS5229093A (en) Method of preventing corrosion of propeller shaft system
JPS5567530A (en) Glass tube strengthening method

Legal Events

Date Code Title Description
PE Patent expired