CA2257267A1 - High turbulence mixer - Google Patents

High turbulence mixer Download PDF

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Publication number
CA2257267A1
CA2257267A1 CA002257267A CA2257267A CA2257267A1 CA 2257267 A1 CA2257267 A1 CA 2257267A1 CA 002257267 A CA002257267 A CA 002257267A CA 2257267 A CA2257267 A CA 2257267A CA 2257267 A1 CA2257267 A1 CA 2257267A1
Authority
CA
Canada
Prior art keywords
stator
mixer
rotor
tongue
boss
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.)
Abandoned
Application number
CA002257267A
Other languages
French (fr)
Inventor
John L. Rogers
Brian J. Gallagher
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.)
Beloit Technologies Inc
Original Assignee
Individual
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 Individual filed Critical Individual
Publication of CA2257267A1 publication Critical patent/CA2257267A1/en
Abandoned legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F25/00Flow mixers; Mixers for falling materials, e.g. solid particles
    • B01F25/30Injector mixers
    • B01F25/31Injector mixers in conduits or tubes through which the main component flows
    • B01F25/313Injector mixers in conduits or tubes through which the main component flows wherein additional components are introduced in the centre of the conduit
    • B01F25/3132Injector mixers in conduits or tubes through which the main component flows wherein additional components are introduced in the centre of the conduit by using two or more injector devices
    • 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
    • B01F27/112Stirrers characterised by the configuration of the stirrers with arms, paddles, vanes or blades
    • B01F27/1125Stirrers characterised by the configuration of the stirrers with arms, paddles, vanes or blades with vanes or blades extending parallel or oblique to the stirrer axis
    • 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
    • B01F27/50Pipe mixers, i.e. mixers wherein the materials to be mixed flow continuously through pipes, e.g. column mixers
    • 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
    • B01F27/84Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis with two or more stirrers rotating at different speeds or in opposite directions about the same axis

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Mixers Of The Rotary Stirring Type (AREA)
  • Accessories For Mixers (AREA)

Abstract

This invention describes a mixer which includes a rotatable hollow cage vaned rotor in combination with an offset stator having at least one foil on the stator. Also described is an apparatus for medium pulp mixing which includes an essentially cylindrical entry section, a mixing zone adjacent to the entry section, the mixing zone utilizing the rotatable hollow cage vaned rotor in combination with an offset stator having at least one foil on the stator and an exit section adjacent to the mixing section. The apparatus may include a chemical addition component, the location of which can either be within the entry section or an orifice on the stator tongue.

Description

.CA 022~7267 l998-l2-02 High Turbulence Mixer Technical Fie/d The invention described herein pertains to pulp processing equipment, and more particularly to an apparatus and method for mixing low or medium consistency pulp with at least one chemical reagent.

Background of the /nvention In a bleach plant, pulp is subjected to the addition of chemical reagents, some gaseous form and others already in solution. For a general discussion of an ozone bleaching method and equipment used in such a method, refer to International Publication No. WO 94/29514. Low consistency mixing is normally carried out at 3-5% consistency and medium consistency is carried out at 9-18% consistency.
Consistency is defined as the percentage by weight of cellulose fiber in a mixture of fiber and liquor. For economic considerations, it is important to perform the bleaching process at as high a consistency as feasible. However, when bleaching cellulose and other materials at high pulp concentration, it is difficult to achieve a rapid and homogeneous mixing of the chemicals into the material being treated. Difficulty is usually encountered when consistencies of 10% or greater are used and in practice, it has been shown to be almost impossible to mix chemicals effectively at concentrations above 18%.

The prior art teaches that effective chemical mixing is difficult to achieve economically. Thus, there exists a need for a more efficient configuration for the addition and mixing of chemicals into a pulp bleaching process streams.

Summary of the /nvenfion In accordance with the present invention, there is provided a simpie, inexpensive mixer for pulp plant bleaching operations which promotes uniform distribution of the bleaching chemicals so that the residence time in the bleaching tower is maximized.

AMi-NDE~ S~EET

CA 022~7267 1998-12-02 WO 97146310 PCTrUS96/085~1 It is an object of this invention to provide a high turbulence mixer which uses a vaned hollow cage rotor in combination with a tongued stator.
It is another object of this invention to provide a high turbulence mixer in which a vaned hollow cage rotor and a ton~e~ stator both rotate to m~lrimi7e 5 mixing.
It is still another object of this invention to provide a unit which is an in-line device which can be retrofftted without major piping modifications to the ting plant.
It is yet another object of this invention to provide a unit which is an in-10 line device which con~-~m~s as little power as necess~-y and operates over a wide range of con~ictPnry and tonnages.
These and other objects of this invention will be evident when viewed in light ofthe dl~willgs, det~ilPd description, and appended claims.

Brief D~ ,.~lion of the Drawings The invention may take physical form in certain parts and arr~ng~mPnt~ of parts, a preferred embodiment of which will be described in detail in the specific~tion and illustrated in the accol"p&"ying drawings which form a part hereof, and wherein:
Fig. 1 is a perspective view of a hollow cage rotor showing four vanes;
Fig. 2 is a perspective view of a ton~led adjustable stator;
Fig. 3 is a side view in partial cross-section showing the hollow cage rotor and stator inline of a mixer wherein the inlet and exit sections are in es~ç~ y linear ~lignmPnt;
Fig. 4 is a side view in partial cross-section showing the hollow cage rotor and stator irlline of a mixer wherein the inlet and exit sections are not in linear ~lignm~nt; and .

CA 022~7267 1998-12-02 W O 97/46310 PCTrUS96/08551 Fig. 5 is a cross-sectional view shown in partial cross-section along line 4-4 of Fig. 4.

Defailed D.;..~-,.iJlion of the Invent on S Referring now to the drawings wherein the showings are for purposes of illustrating the prerel,ed embodiment ofthe invention only and not for purposes Of limiting the same, the Figures show a high turbulence mixer for pulp which uses a hollow cage vaned rotor in combination with a ton~led stator.
The mixer ~0 of the invention coll,plises the combination of a hollow cage rotor 10 in association with a tongued adjustable stator 2û. As shown in Fig. 1,the hollow cage rotor col-l~lises a variable number of vanes 6 (ranging from at least 2 to 12 in number), the vanes physically connected to a rotor base 8 and arotor boss 4 at opposed ends of the vanes. A rotating shaft 2 is typically af~lxed to rotor boss 4 centered about the axis of rotation of the rotor. The rotor may be pulley or direct-driven depending upon the application. The number of vanes is generally dependent upon mixer size, piping capacity and pulp coniictency. The vanes serve to .,.~;..l;~;l. the coaxial relationship ofthe rotor boss and rotor base and can have many di~rerelll geometries. The vanes can be perp~nrlic~ r to the bottom surface of the rotor boss with the lQngitu~lin~l axis of any one vane in parallel ~lignm~?nt with the longitll-lin~l axis of the rotating shaft, or skewed or even spiraled wherein the vanes are usually equally spaced about the ~,h~iull~,t;nce ofthe rotor boss but for which an axis drawn between the ~tt~rhm~nt points of the vane to the rotor boss and rotor base would not result in a parallel ~lignm~nt with the longitu(lin~l axis ofthe rotating shaft.
In general, the ~ m~,ter ofthe rotor base 8 is e~e~nti~lly the same as that of the rotor boss 4. However, in certain speci~li7ed in~t~nt~es~ the ~ m~t~r of the rotor base may be larger or smaller than the rotor boss. VVhen in this confi~lration, the vanes may once again, either be in e~nti~lly a straight line W O 97/46310 PCT~US~6/085',1 confi~-ration ~m~n~ting from the bottom surface of the rotor boss and lc~ ing at the rotor base, or in a skewed or even spiral configuration.
As seen in Fig. 2, the stator 20 comprises a tongue 14, which fits inside the rotor cage. The stator can be concentric or off-set depending upon the 5 appliç~tion The tongue ofthe stator in a p,eft;l.ed embodiment, has at least one tongue foil 16 about the periphery of the tongue. The al~ gf~ .nt of the foils can be normal to the surface of the tongue as shown, or the tongue foils can be in a spiral configuration about the stator tongue. While not shown in Fig. 2, it ispossible for the stator to also have a rotation shaft in a marmer similar to that 10 shown in Fig. 1 for the rotor.
As best shown in Fig. 3, in one embodiment, the high turbulence mixer is positioned in a ll~nsvel~e direction to the inline pulp/liquor stream 22. The flanged piping 26 has an entry section 40, a mixing zone 42 and an exit section 44. Pulp/liquor 22 is received into the entry section 40 and ble?~-.hing çhPmic~l~
15 are added through ch~miç~l entry nozzle 28, optionally fitted with a direr,tiQn~l flap 52 for use in ~h~nn~ling the flow o~the chemicals into the pulp stream.
Subsec~nt to the entry section 40 is mixing zone 42 wherein a ton~-ecl stator 20 is positioned inside of rolaLi.~, hollow cage rotor 10. The ~ u~e of pulp and liquor is subjected to intense turbulence and shear forces in mixing zone 20 42. In a pre~lled embodiment, the stator tongue 14 is con~entric or off-set of the lon itllrlin~l axis 34 of the hollow cage rotor shaft 2. As shown in Fig. 3,hollow cage rotor rotates about the ton~led stator creating two mixing int~n~iti~
in the same device, i.e., on the outlet side, higher shear forces will be generated due to the smaller gap between the rotor and the stator, while on the inlet side, a 25 milder turbulence will be generated due to the wider gap. It is imperative that the çhemic~l be well mixed with the pulp prior to discharge stream 46 in exit section 44.

CA 022~7267 1998-12-02 While the stator has been described as non-rotating, there is no need to limit it to such. In an alternative embodiment, both the hollow cage rotor and tongued stator rotate. In one aspect of this embodiment, the rotation of the hollow cage rotor is opposite to that of the tongued stator.
Alternative configurations for the mixer 50 are also envisioned. As shown in Fig. 4, the exit section 44 need not be oriented in longitudinal alignment with the entry section 40. It is also within the scope of this invention to have the chemical addition occur at a point other than that identified previously as chemical entry nozzle 28. In some instances, it may be desirable to add the chemicals into the turbulence created at the rotor/stator interface. This type of configuration is shown in Fig. 3 where the chemical addition occurs through orifices 48 positioned either along the longitudinal axis of stator tongue 14 or through orifices 18, as shown in Fig. 2, on the tongue.
Fig. 5 shows a cross-section of Fig. 4 taken along line A-A. The offset 36 of the tongue 14 in comparison to the longitudinal axis 34 of the stator is evident. The distance between the tongue of the stator and the inside of the rotor vanes 6 can be adjusted to suite the target application.
The invention has been described with reference to preferred and alternate embodiments. Obviously, modifications and alterations will occur to others upon the reading and understanding of the specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

AM~ S,tE'~T

Claims (25)

What is claimed is:
1. A high turbulence mixer (50) for pulp, comprising: a rotatable hollow cage rotor (10), the rotor having an essentially cylindrical rotor boss (4) having opposed surfaces, a rotor shaft (2) attached along a longitudinal axis of the rotor on one surface of the boss and at least two vanes (6) having opposed ends, one vane end of each vane communicating with the second surface of the boss, the other vane end of each vane communicating with a rotor base (8); and a stator (20) having an essentially cylindrical stator boss (12) having opposed surfaces and a tongue (14) attached to one surface of the stator boss characterized in that:
the tongue of the stator is positioned inside the hollow rotor cage such that the rotor boss of the cage rotor is in opposed directional relationship with the stator boss of the stator.
2. The mixer of claim 1 wherein the stator further comprises at least one foil (16) about a periphery of at least a portion of a length of the tongue.
3. The mixer of claim 2 wherein the stator further comprises at least two foils about a periphery of at least a portion of the length of the tongue.
4. The mixer of claim 2 wherein a longitudinal axis of the foil is parallel with a longitudinal axis of the tongue.
5. The mixer of claim 2 wherein the foil spirals about at least a portion of thelength of the tongue.
6. The mixer of claim 2 wherein the stator further comprises a stator shaft attached along the longitudinal axis of the stator boss.
7. The mixer of claim 6 wherein the stator rotates within the hollow cage rotor.
8. The mixer of claim 7 wherein the stator rotates in an opposite direction to arotation of the hollow cage rotor.
9. The mixer of claim 1 wherein the stator has at least one orifice (48) on the tongue whereby at least one chemical reagent is added through the orifice.
10. The mixer of claim 1 wherein a longitudinal axis of the vane is collinear with and parallel to the longitudinal axis of the rotor.
11. The mixer of claim 1 further characterized in that it comprises:
(a) an essentially cylindrical entry section (40);
(b) a mixing zone (42) adjacent to the entry section; and (c) an exit section (44) adjacent to the mixing section.
12. The mixer of claim 11 wherein the entry section further comprises a chemicaladdition means.
13. The mixer of claim 11 wherein the mixing section further comprises a chemical addition means.
14. The mixer of claim 13 wherein the chemical addition means is at least one orifice (48) on the stator tongue.
15. The mixer of claim 11 wherein the exit and entry sections are essentially collinear.
16. The mixer of claim 11 wherein the exit and entry sections are in a nonlineararrangement.
17. The mixer of claim 11 wherein the stator further comprises at least one foilabout a periphery of at least a portion of a length of the tongue.
18. The mixer of claim 17 wherein the stator further comprises a stator shaft attached along the longitudinal axis of the stator boss.
19. The mixer of claim 18 wherein the stator rotates within the hollow cage rotor.
20. The mixer of claim 19 wherein the stator rotates in an opposite direction to a rotation of the hollow cage rotor.
21. The mixer of claim 11 wherein a longitudinal axis of the vane is collinear with and parallel to the longitudinal axis of the rotor.
22. The mixer of claim 1 wherein the stator axis is concentric with respect to the axis of the cage rotor.
23. The mixer of claim 1 where the stator axis is off-set with respect to the axis of the cage rotor.
24. The mixer of claim 11 wherein the stator axis is concentric with respect to the axis of the cage rotor.
25. The mixer of claim 11 where the stator axis is off-set with respect to the axis of the cage rotor.
CA002257267A 1996-06-03 1996-06-03 High turbulence mixer Abandoned CA2257267A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US1996/008551 WO1997046310A1 (en) 1996-06-03 1996-06-03 High turbulence mixer

Publications (1)

Publication Number Publication Date
CA2257267A1 true CA2257267A1 (en) 1997-12-11

Family

ID=22255208

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002257267A Abandoned CA2257267A1 (en) 1996-06-03 1996-06-03 High turbulence mixer

Country Status (5)

Country Link
EP (1) EP0912236A1 (en)
JP (1) JPH11511694A (en)
CA (1) CA2257267A1 (en)
ID (1) ID17739A (en)
WO (1) WO1997046310A1 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5863120A (en) * 1997-01-31 1999-01-26 Beloit Technologies, Inc. Medium consistency liquid mixture
AT413017B (en) * 2002-03-21 2005-10-15 Andritz Ag Maschf METHOD AND DEVICE FOR MIXING FLUIDS INTO FLOWABLE MEDIA
AT413018B (en) * 2002-03-21 2005-10-15 Andritz Ag Maschf METHOD AND DEVICE FOR PROMOTING FLOWABLE MEDIA
JP5569671B2 (en) * 2009-05-20 2014-08-13 極東産機株式会社 Glue melting device
FR2997635A1 (en) * 2012-11-05 2014-05-09 Spcm Sa DEVICE FOR INJECTION THEN MIXING POLYMER IN A CANALIZATION TRANSPORTING SUSPENSION OF SOLID PARTICLES AND METHOD IMPLEMENTING THE DEVICE

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US221260A (en) * 1879-11-04 Improvement in blacking-box holders
US2212260A (en) * 1938-02-12 1940-08-20 Brothman Abraham Dispersion device and the like
GB729609A (en) * 1953-03-16 1955-05-11 Carsten Mohler Sorensen Device for use in the manufacture of margarine and other semi-solid edible fats
US3033540A (en) * 1959-09-23 1962-05-08 Rosin Ira Mixing apparatus
JPS5947695B2 (en) * 1975-07-25 1984-11-21 帝人株式会社 Pulp particle manufacturing equipment
JPS597497B2 (en) * 1980-07-25 1984-02-18 不二パウダル株式会社 mixer
DE3446741A1 (en) * 1984-12-21 1986-07-03 GVA mbH, 4020 Mettmann Method and device for generating horizontal flow motion in liquids
JPS61227826A (en) * 1985-04-01 1986-10-09 Imamura Seisakusho:Kk Stirring device
JPH04176333A (en) * 1990-11-09 1992-06-24 Mitsui Petrochem Ind Ltd Method for supplying reaction component and solution reactor
SE502665C2 (en) * 1993-06-11 1995-12-04 Kvaerner Pulping Tech Methods and reactor for ozone bleaching

Also Published As

Publication number Publication date
EP0912236A1 (en) 1999-05-06
ID17739A (en) 1998-01-22
JPH11511694A (en) 1999-10-12
WO1997046310A1 (en) 1997-12-11

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Legal Events

Date Code Title Description
EEER Examination request
FZDE Discontinued