EP0158048B1 - Mixing systems - Google Patents

Mixing systems Download PDF

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Publication number
EP0158048B1
EP0158048B1 EP85101696A EP85101696A EP0158048B1 EP 0158048 B1 EP0158048 B1 EP 0158048B1 EP 85101696 A EP85101696 A EP 85101696A EP 85101696 A EP85101696 A EP 85101696A EP 0158048 B1 EP0158048 B1 EP 0158048B1
Authority
EP
European Patent Office
Prior art keywords
impeller
blades
edges
fact
fibers
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.)
Expired - Lifetime
Application number
EP85101696A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0158048A2 (en
EP0158048A3 (en
Inventor
Ronald J. Weetman
Jerry A. Carpenter
Chandler K. Coyle
Keith T. Mcdermott
Roger N. Voss
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.)
SPX Corp
Original Assignee
General Signal Corp
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 General Signal Corp filed Critical General Signal Corp
Publication of EP0158048A2 publication Critical patent/EP0158048A2/en
Publication of EP0158048A3 publication Critical patent/EP0158048A3/en
Application granted granted Critical
Publication of EP0158048B1 publication Critical patent/EP0158048B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
    • B01F27/80—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis
    • B01F27/91—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis with propellers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
    • B01F27/05—Stirrers
    • B01F27/11—Stirrers characterised by the configuration of the stirrers
    • B01F27/113—Propeller-shaped stirrers for producing an axial flow, e.g. shaped like a ship or aircraft propeller
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F33/00—Other mixers; Mixing plants; Combinations of mixers
    • B01F33/86—Mixing heads comprising a driven stirrer
    • B01F33/862—Mixing heads comprising a driven stirrer the stirrer being provided with a surrounding stator

Definitions

  • the present invention relates to mixing and circulating liquids having fibers suspended therein.
  • the present invention is especially suitable for use in mixing systems designed to treat waste water by the circulation of the water in tanks with an axial flow impeller in a draft tube.
  • the invention is also suitable for use in other mixing applications liquid is circulated with an axial flow impeller.
  • the apparatus used in the invention is of the general type disclosed in our U.S. Patent 4,378,165, namely apparatus for circulating liquids having fibers suspended therein in a tank which comprises a draft tube disposed in said tank, a shaft an axial flow impeller on said shaft having a plurality of blades, said impeller being disposed in the draft tube and the shaft and impeller being coaxial with the draft tube, said blades having opposite edges one of which leads the other as the impeller rotates.
  • a system for mixing liquids in a tank in accordance with the invention utilizes an impeller which has opposite edges which respectively lead and trail each other as the impeller rotates.
  • This system is operative to circulate the liquids through the tank along a flow path which extends axially of the impeller.
  • the adhesion of fibers suspended in the liquid along the leading edge of the impeller is decreased, thereby preventing increased drag on the impeller due to the accumulation of the fibers on the leading edge as the impeller rotates.
  • the adhesion is decreased by inclining the leading edge with respect to a radial line from the axis of the impeller sufficiently to be greater than the angle of repose of the fibers on the impeller.
  • the angle of repose is that angle where the forces normal to the leading edge are sufficient to hold the fibers against the leading edge, considering the coefficient of friction of the surface of the impeller at the leading edge with respect to the fibers.
  • the leading edge presents an inclined plane with an inclination larger than the angle of repose. Accordingly, the fibers are not held with sufficient force to maintain them on the leading edge, and they continue to circulate with the liquid. This is in spite of the absence of any significant radial component of flow; the flow being essentially axial, particularly where the impeller is an axial flow impeller in a draft tube.
  • the adhesion of the fibers along the leading edge may also be further decreased by providing the portion of the impeller adjacent the leading edge with a surface of low coefficient of friction material, such a low coefficient of friction may be provided by polishing.
  • Low coefficient of friction material is preferably provided by utilizing a plastic material presenting a low coefficient of friction to the fibers.
  • a tank 10 which may be used for the mixing of liquids, such as waste water, having fibers in suspension.
  • a draft tube 12 having a conical upper section 14 and a cylindrical lower section 16, is suspended from a beam 18 by posts 20. The lower section may also be diverging.
  • the beam 18 also carries a drive assembly 22 including an electric motor 24 and gearing 26. Suitable bearings in the gearing section 26 rotatably support a drive shaft 28.
  • An impeller 30 having a plurality of blade 32 is connected to a hub 34 which is connected to and driven by the drive shaft 28.
  • the draft tube sections 14 and 16 define an impeller way 36.
  • each blade 32 has an airfoil profile.
  • the chord of the blade (CL) is measured beween its leading edge 38 and its trailing edge 40.
  • the blade has camber as measured between its midline 42 and chord.
  • the blade also has twist, as shown in FIG. 3, in that the angle between the chord and the lower surface of the blade is greater at the base 35 of the blade than at the tip 44 thereof, and may be 10-18 0 greater.
  • the camber may have a maximum length or value of from about 4 to 8 percent of the chord length. The location of the maximum camber length may be from about 20% to about 60% of the chord length away from the leading edge 38 towards the trailing edge 40.
  • the blade also has thickness between its upper and lower surfaces preferably from about 6 to 14 percent of the chord length.
  • the width of the blade at the hub may be 22-28% of the chord length.
  • the width of the blade at the tip may be 14-20% of the chord length.
  • the tip chord angle between the chord at the tip and the horizontal may be 5-25°.
  • the blade may be constructed from a pair of plates 46 and 48, as shown in FIG. 4 which may be welded together near the leading and trailing edges.
  • An insert 50 is provided in a portion extending approximately 10 percent of the length of each of the upper and lower surfaces from the leading to the trailing edge 38 and 40 of each blade 32. This insert is preferably a body of plastic materials which presents a surface having a low coefficient of friction.
  • Ultra high molecular weight polyethylene (“UHMW”).
  • UHMW ultra high molecular weight polyethylene
  • the molecular weight of-this material is approximately 5 million.
  • Suitable material is available from Poly-Hi/Menasha Corp. Under the trade name TIVAR O.
  • Other material presenting a low coefficient of friction is suitable, for example a flouropolymer (such as known by the trade name Teflon°). Ultra high molecular weight polyethylene is preferred.
  • the tips 44 .of the blades 32 have the shape of a sector of a circle and conform to the cylindrical inner periphery of the draft tube; extending to the inner periphery of the lower section 16, and separated therefrom only the necessary clearance to maintain manufacturing tolerances.
  • the leading edge 38 is also longer than the trailing edge 40.
  • the leading edge has an arcuate section 52 near the base end 35 and extends to a straight section 54.
  • the trailing edge 40 is entirely straight.
  • the arcuate section 52 is provided in order that the inclination of the leading edge can be sufficient so that the angle of repose of fibers which tend to accumulate on the leading edge is not reached.
  • This angle of repose may be measured between the leading edge and radial lines extending from the axis 56 of the impeller (the center line of the shaft 28 and hub 34).
  • the angle indicated as, 8, in FIG. 2 between a radial line 60 in a plane perpendicular to the axis 56 which intersects the leading edge 38 at a point 62, where the radial line has a length RL, equal to 70 percent of the radius of the blade from the ti p 44 to the axis 56 is 40°.
  • This angle of inclination, 6, may be in a range from 20° to 60° depending upon the nature of the fibers which are suspended in the liquid being mixed and the coefficient of friction of the surface provided by the insert 50.
  • a sufficient inclination angle 8 will suffice.
  • the portion of the surface at the leading edge with a low coefficient of friction may be polished.
  • the low coefficient of friction material may be coated or otherwise bonded onto the surface.
  • the impeller 30 may be provided with blades 64 of a design shown in FIG. 5. These blades may be of airfoil profile their leading edges 66 are sectors of a circle.
  • the angle of inclination, ⁇ is measured at the intersection 62 of the radial line 60 of length 70% of the radius to the top 70 of the blade with the leading edge 66.
  • the center of the sector is shown at 68 along a line perpendicular to tangent line 72.
  • the trailing edge 74 of the blade is made up of two arcs, one of which 76 is a sector of a circle having its center at 68 and the other of which 78 is also a sector of a circle having its center 80 within the blade 64.
  • the portion 81 of the blade adjacent the leading edge 66 may be provided by an insert of low coefficient of friction material, similar to the insert 50.
  • the other techniques mentioned above, for providing low coefficient of friction in the surfaces of the portion 81, may alternatively be used.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Mixers Of The Rotary Stirring Type (AREA)
  • Aeration Devices For Treatment Of Activated Polluted Sludge (AREA)
  • Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
EP85101696A 1984-04-11 1985-02-15 Mixing systems Expired - Lifetime EP0158048B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US59910984A 1984-04-11 1984-04-11
US599109 1984-04-11

Publications (3)

Publication Number Publication Date
EP0158048A2 EP0158048A2 (en) 1985-10-16
EP0158048A3 EP0158048A3 (en) 1986-10-08
EP0158048B1 true EP0158048B1 (en) 1990-10-31

Family

ID=24398251

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85101696A Expired - Lifetime EP0158048B1 (en) 1984-04-11 1985-02-15 Mixing systems

Country Status (10)

Country Link
EP (1) EP0158048B1 (ko)
JP (1) JPH0644981B2 (ko)
KR (1) KR920000538B1 (ko)
AU (1) AU569364B2 (ko)
CA (1) CA1249809A (ko)
DE (1) DE3580294D1 (ko)
GB (1) GB2157185A (ko)
NZ (1) NZ210861A (ko)
PH (1) PH22693A (ko)
SG (1) SG15392G (ko)

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB8617569D0 (en) * 1986-07-18 1986-08-28 Davidson J F Impellers
US5112192A (en) * 1990-07-26 1992-05-12 General Signal Corporation Mixing impellers and impeller systems for mixing and blending liquids and liquid suspensions having a wide range of viscosities
US5344235A (en) * 1993-01-21 1994-09-06 General Signal Corp. Erosion resistant mixing impeller
BE1010118A3 (fr) * 1996-04-05 1998-01-06 Magotteaux Int Helice de malaxeur.
FR2784311B1 (fr) * 1998-10-09 2000-12-08 Air Liquide Dispositif d'agitation d'un liquide dans un reacteur et d'injection d'un gaz dans ce liquide
KR100462245B1 (ko) * 2002-07-15 2004-12-17 김승희 약품 용해장치
AU2006202877B2 (en) * 2005-06-30 2010-12-02 Spx Flow, Inc. Mixing impeller and method with weld locations
US20070002686A1 (en) * 2005-06-30 2007-01-04 Spx Corporation Mixing impeller and method with top and bottom skin elements
US7481573B2 (en) 2005-06-30 2009-01-27 Spx Corporation Mixing impeller with pre-shaped tip elements
US20070003415A1 (en) * 2005-06-30 2007-01-04 Spx Corporation Mixing impeller and method with weld locations
KR100852551B1 (ko) 2007-02-07 2008-08-18 대우조선해양 주식회사 선박 탱크의 침전방지장치
JP2011240230A (ja) * 2010-05-17 2011-12-01 Hitachi Plant Technologies Ltd 攪拌機の運転方法
JP2015205250A (ja) * 2014-04-22 2015-11-19 日立造船株式会社 攪拌装置
CN104959066B (zh) * 2015-06-12 2019-01-18 中国核电工程有限公司 一种用于核废物处理的搅拌桨及搅拌装置
CN106422866B (zh) * 2016-09-27 2018-09-28 嘉兴晟源工业设计有限公司 一种具有搅拌和罐装功能的一体式药粉搅拌机
KR20200066282A (ko) * 2017-10-12 2020-06-09 도레이 카부시키가이샤 미디어형 분산기 및 액상 분산물의 제조 방법
CN111998757B (zh) * 2020-08-28 2022-06-14 河海大学常州校区 一种粘性土水下休止角的测量装置及其方法
KR102527653B1 (ko) * 2021-01-13 2023-05-02 오브맘코리아컴퍼니 주식회사 천연 5종 컴플렉스 항균 원료 조성물 및 그 제조 장치

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB296247A (en) * 1928-01-09 1928-08-30 Pfaudler Co Inc Improvements in or relating to rotary agitators
GB1026384A (en) * 1962-06-05 1966-04-20 Activated Sludge Ltd Improvements in or relating to aerators
US3367423A (en) * 1966-06-13 1968-02-06 Cornelius W. Van Ranst Propeller
SE385819B (sv) * 1972-11-13 1976-07-26 S Hjorth Propeller
US3870195A (en) * 1973-04-26 1975-03-11 Saco Lowell Corp Apparatus for and method of feeding bobbin tubes
FR2315001A1 (fr) * 1975-06-18 1977-01-14 Entat Marcel Procede de realisation de pales d'helices et pales d'helices perfectionnees obtenues par la mise en oeuvre de ce procede
JPS556081U (ko) * 1978-06-29 1980-01-16
US4231974A (en) * 1979-01-29 1980-11-04 General Signal Corporation Fluids mixing apparatus
JPS5639196U (ko) * 1979-09-04 1981-04-13
US4378165A (en) * 1980-12-30 1983-03-29 General Signal Corporation Draft tube apparatus
US4468130A (en) * 1981-11-04 1984-08-28 General Signal Corp. Mixing apparatus
EP0079396A1 (de) * 1981-11-12 1983-05-25 Hans Kimmel Flügel für ein rotierendes Misch- und Rührwerkzeug
US4480796A (en) * 1982-01-25 1984-11-06 Beloit Corporation Pulping apparatus including improved rotor
GB2143440A (en) * 1983-07-21 1985-02-13 Morton Robert Dg Ltd Mixers
JPS6119794U (ja) * 1984-07-10 1986-02-05 石川島播磨重工業株式会社 高速増殖炉

Also Published As

Publication number Publication date
AU3760685A (en) 1985-10-17
PH22693A (en) 1988-11-14
GB2157185A (en) 1985-10-23
EP0158048A2 (en) 1985-10-16
DE3580294D1 (en) 1990-12-06
AU569364B2 (en) 1988-01-28
KR920000538B1 (ko) 1992-01-16
CA1249809A (en) 1989-02-07
SG15392G (en) 1992-04-16
JPH0644981B2 (ja) 1994-06-15
NZ210861A (en) 1986-09-10
KR850007219A (ko) 1985-12-02
GB8504508D0 (en) 1985-03-27
EP0158048A3 (en) 1986-10-08
JPS60227821A (ja) 1985-11-13

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