US3207488A - Dispersing device - Google Patents

Description

Sept. 21, 1965 E. 'r. BRASINGTON 3,207,488

DISPERSING DEVICE Filed April 19, 1961 5 Sheets-Sheet 1 I NVE N TOR. Euqgyi IBRAs/A/q TON. DES JRDINS RO/NSON.

H15 ATTORNEYS Sept. 21, 1965 E. T. BRASINGTGN DISPERSING DEVICE 3 Sheets-Sheet 2 Filed April 19, 1961 AME //////// ///////J) EUENE EBRQS/NGTON- Sept. 21, 1965 E. T. BRASINGTON 3,207,488

DISPERSING' DEVICE Filed April 19, 1961 3 Sheets-Sheet s i I I 31 l 3c 37 5 34 41 4s Hg? INVENTOR.

Euqgys TI BRASINGTON.

DES (MEDIA/@ 81 ROBINSON.

HIS ATTORNEYS United States Patent 3,207,488 DISPERSING DEVICE Eugene T. Brasington, Fairview, Pa., assignor to Patterson Industries, Inc., East Liverpool, Ohio, a corporation of Ohio Filed Apr. 19, 1961, Ser. No. 107,010 Claims. (Cl. 25984) This is a continuation-in-part of my copending application Serial No. 660,848, filed May 22, 1957, now abandoned.

This invention relates to a dispersing device for intermixing two or more components into a homogenous mass, and it particularly pertains to a disperser for intimately commingling the components of an emulsion or for finely divided solid particles which are to be combined with a liquid or semi-liquid to form a homogenous intermixed mass in which all of the individual solid particles are dispersed within the liquid or semi-liquid to be wetted thereby for being intimately commingled therewith.

The dispersing device may be used alone, but it is particularly adapted for use with conventional mixers and especially change can mixers, such as those which are used for mixing paints, inks and like mixtures.

One type of mixer with which the dispersing device is particularly adapted for use is that of the type shown in US. Patent 2,657,911 and which is incorporated herein in full as a part of the disclosure of this invention for showing the general type of angular change can mixers to which the disperser of the present invention may be added. It may, of course, be used with change can mixers of other than the angular type. These mixers move the heavier components, such as the solid particles which tend to gravitate to the bottom and into the bottom corner, to the interior of the container for being intermixed with the liquid component or phase, but there is no mulling action effected upon the components of the mixture in addition to the section of the mixing blades. Moreover, the mixing blades do not have impinging surfaces for creating hydraulic shear adjacent to a mulling zone. In these mixers, only a very small quantity of liquid is first mixed with the solid materials, the amount of the liquid being preferably just enough to thoroughly wet the surface of the solid particles and form a mass of heavy consistency. Then after the solid components have been intimately mixed with the liquid, more liquid is added to bring the consistency of the mixture to that suitable for use. During this primary mixing stage, the mixture is of a heavy paste consistency in the nature of a plastic mass, as more effective intermingling of the components is obtained.

Accordingly, one of the main objects of this invention is a disperser which is of novel and improved construction.

Another object of the invention is a disperser disposed in respect to the mixing container to provide a mulling zone.

Another object of the invention is a disperser provided with improving impinging surfaces adjacent the mulling zone.

Another object of the invention is a disperser which is simple in construction and eflicient in operation.

Still another object of the invention is a disperser which is adapted to be used in combination with any conventional mixer.

A further object of the present invention is a disperser which is adapted to be used in combination with a rotating tank.

Another object of the present invention is to provide the combination of an eccentrically mounted disperser, a rotating tank and an agitator.

In one instance, the objects of the invention have been accomplished by the device and means set forth in the following specification. The invention is clearly defined and pointed out in the appended claims, and a structure constituting one embodiment of the invention is illustrated in the accompanying drawings, in which:

FIG. 1 is a perspective view of an angular change can mixer, with the mixing can removed, equipped with a disperser embodying the invention.

FIG. 2 is a top plan view of the impeller of the disperser.

FIG. 3 is a cross-sectional view of the mounting for the disperser.

FIG. 4 is a detailed view of the impeller of the disperser.

FIG. 5 is a bottom view of the impeller of FIG. 4.

FIG. 6 is a cross-sectional view of the impeller of the disperser.

FIG. 7 is a cross-sectional view of another embodiment of the impeller of the dispenser.

Referring specifically to the drawings in which like numerals designate like parts, there is an angular mixer (FIG. 1) having a base 1 provided with a turntable 2, rotatably mounted on one end, on which an open top can or container 3 (FIG. 4) may be placed and secured in a conventional manner. A motor 4 is mounted on the opposite end of the base with suitable driving connections (not shown) between it and the turntable 2. The container 3 is seated on the turntable 2 with its top open end in position to be closed by a lid or cover 5 which is fixed to support 6 that is in turn pivoted to the base 1 for being raised or lowered with the mixing unit 7 thereon to withdraw the mixing agitator 8 from the container or to project it therein. The mixing agitator 8 is projected through an opening in the lid or cover 5 and is driven by an electric motor 9 carried on the pivoted support 6. A subcover 10 is hinged to the main cover 5 to give access to the interior of the container without lifting the main cover. The mixing agitator 8 is of such shape to conform to the inside corner of the container 3 for portions 8a to be close to the side Wall of said container and the portions 8b to be close to the bottom wall adjacent the corner when the agitator 8 is revolving. The free end of the agitator 8 is on a line bisecting the corner angle of the container.

The foregoing described construction is substantially as shown and described in said Patent 2,657,911, and it is with such type mixer that the disperser of the present invention may be added and driven by the common motor 9 for the mixer with the suitable driven mechanism, or by a separate motor 11, also preferably supported on support 6.

In general then it will be seen that I have provided a mixer having a rotating tank similar to that formerly used in change can mixers or plain pony mixers, but in combination with a disperser and an agitator 8. The agitator preferably but not necessarily enters at such an angle that its axis bisects the angle between the side and the bottom of the container. It is generally made in the form of a diamond whose forward point reaches down into the corner of the tank with the two adjacent legs at the same angle as the bottom and sides of the tank, in most cases, This permits the agitator to sweep past the bottom and side of the tank and, by its compressive action on the material, to cause it to be displaced from the bottom and side of the tank; at the same time, sweeping the material upward and outward from the bottom and downward and inward from the side thereby having a very good three dimensional mixing action.

Mounted on top of the pivoted support 6 above the container 3 is a housing unit comprising a cylindrical tubular body 12 having a bearing head 13, with an offset peripheral shoulder 14, secured to its top end as by bolts 15. The offset shoulder 14 provides a portion 13' on the bearing head 13 for fitting into the end of the tubular member. The bottom end of the tubular body 12 is welded at 16 to the top side of a plate 17 in registration with a central circular hole 18 formed in said plate 17 for another bearing head 19, of the same construction as hearing head 13, to be bolted against the bottom side of said plate 17 by means of bolts 20. This plate 17 is fastened to a metal ring 21 by bolts 22, said ring 21 being a part of or fixed to the pivoted mounting 6. This bottom plate 17 is in effect a bottom flanged end of the tubular body 12.

Rotatably mounted. within these two bearing heads 13 and 19 is a spindle shaft 23 having a sheave 24 fixed to its top end in alignment with a corresponding sheave 25 on the shaft 11' of motor 11. An antifriction bearing 26 is fitted within a socket in the top and bottom bearing heads 13 and 19 for rotatably mounting the spindle shaft 23. The spindle shaft 23 is mounted within the housing 12 and fitted to the inner raceways 26' of the bearings 26 and held in verticalposition. The bottom end of the spindle shaft 23 extends into the container 3 through a hole 27'which is formed in the container lid or cover 5, and is of such length for an impeller to be mounted on the bottom end thereof near the bottom of the container.

The inner raceways 26 of the antifriction bearings are clamped to the spindle shaft 23, and this spindle shaft is vertically adjusted to the proper elevation for properly positioning it in respect to the bottom of the container.

A disperser head with impeller 31 is fitted to the bot-tom end of the spindle 23, said head comprising a top ring 32, in which the reduced bottom end 33 of the spindle 23 projects and is Secured, and a bottom ring 34. The bottom end of the spindle is reduced in cross-section for fitting into the top ring 32 with the top edge of said ring abutting against a shoulder 35 of the spindle section 23. These two rings 32 and 34 are connected by a plurality of outwardly and downwardly inclined legs 36, and one of the side edges 37 of each of these legs 36 is inclined or beveled. Ordinarily, the spindle is rotated clockwise in the direction of the arrow, and the side edges 37 are those which are forward when the disperser is so rotated. Accordingly, they are preferably the ones which are beveled. The rear edges 38 of these legs 36 may be likewise beveled, or they may be non-beveled as shown in FIG. 2. This beveled conformation of the side edges 37 of the legs 36, particularly the portions adjacent the bottom ring 34, helps to direct the material through the central aperture 41 of said bottom ring 34 to the hereinafter described mulling zone, and it also prevents the material from banking up in the space between the impeller and the spindle. The inclination of these beveled edges 37 is at approximately a 30 angle to the inner and outer sides 39 and 40 of the legs 36.

Theperipheral outer edge 42 of the bottom ring 34 is provided with a plurality of vertical slots or recesses 43 preferably uniformly spaced circumferentially. These slots or recesses are preferably generally rectangular to have their opposite side walls 44 substantially transversely disposed in a general radial direction to the axis of rotation and extending substantially parallel with said axis of the impeller 31 and the axis of its rotation. The side walls 44 are preferably inclined at an angle not exceeding 30 to 60. The forward side walls 44 of the recesses in the direction of rotation provide impinging surfaces for the mixture for effecting hydraulic shear thereupon.

This disperser is disposed closely adjacent the bottom of the container 3 (FIG. 4) so that the bottom side of the bottom ring 34 and its slotted peripheral outer wall is only a fraction of an inch from the bottom of said container. The maximum distance of the bottom face of the bottom ring 34 from the bottom of the container is not substantially greater than one-half inch and preferably spaced in a range from A to A inch. This distance depends on the consistency of the mixture; The greater the consistency, the greater the distance, whereas, with a mixture of less consistency, the distance is less. The distance is such to effect a mulling action on the mixture. This space provides a mulling zone A between the bottom of the .container and the bottom surface of the bottom of the ring 34 in which the components of the container are mulled. There are three dispersing actions taking place simultaneously, these being the mulling, the hydraulic shear and kinetic impinging resulting from the impinging surfaces of the recesses 43 and the legs 36 of the impeller.

The present mixer thoroughly wets out the dry materials placed in a mix, thus overcoming the difficulties with the balling action that had been experienced with the previous stirring type change can mixers and permits a reduction in the number of mixes and mill runs that are required when mixing heavier inks for which use this machine is particularly suited. Since the great majority of expensive printing inks are of the heavier variety which have very poor flow qualities and which, in turn, do require more mixing and more passes over the roller mill for their production, it is extremely desirable from the standpoint of economics, to be able to combine a dispersing action which goes beyond mere" mixing and actually does some of the work formerly done by the roller mill, and, thus, give the manufacturer production advantages that he has been unable heretofore to obtain. It is preferable that the material flow to the disperser and be pumped in a circulatory manner by the disperser to achieve dispersion, so that all the material in the tank is worked on. mentioned, such flow does not exist and the disc impeller tends to dig a hole for itself with little flow of material 1 to maintain the dispersing action. Th'isaction is strictly a function of the flow qualities of the material. A material having poor flow qualities is one where flow cannot take place fast enough to constantly feed the high speed disperser. Since the present type of dispersing action generates a considerable amount of heat, it is desirable to work on a small portion of the material and thoroughly distribute it in the larger batch in order, to dissipate the heat and, therefore, the disperser head is made smaller and a means provided to feed material to it. It was,

thus, conceived that if such a disperser were developed surface for the material moving fromit.

should be located eccentrically within the tank so as to avoid the rotating agitator and make it possible to tilt and placed in the mixing tank, that the function of feeding the disperser would be accomplished by rotating the tank while the agitator would distribute this material, thus creating a homogeneous product and taking care of heat dissipation.

While it is not essential for the impeller to be placed closely adjacent to the side wall of the container 3, it is preferably so placed. The surface speed of the container is greatest adjacent to its side wall, and the corner of the tank on ordinary mixers,,other than non-angular ones as shown herein, ordinarily present a spot for accumulations of unmixed material, more particularly Where the mixing agitator 8 is not of a type to displace the angular type mixer as here shown, there are no spots for these accumulations.

By having the disperser close to the side of the rotating tank itcan also utilize the side of the tank as an impinging The disperser the machine and have it leave the tank without interference.

These elements-a rotating tank, rotating agitator and rotating disperserserve each other in the following manner: the rota-ting tank continually brings a supply of material to both the agitator and the disperser. majority of the material that is brought to the disperser is. supplied by the rotating tank with the corners of the agitator at right angles to its axis, passing very closely to the disperser shaft, butat this point in rotation, mov- With the heavier types of inks previously The ing in such a direction that it carries material downward and away from the disperser itself. At the same time, this material is carried on around by the tank, where it is again acted on by the agitator in the forward position of the tank for distribution, thus supplying the disperser with material that has been distributed through fresh material and has, thus, reduced the temperature. It is probably well to point out that, as the diamond agitator rotates and passes closely by the bottom and side of the container, that it does forcefully remove material at those points. Of course, there is only a line, both at the bottom and side of the agitator, for each half revolution, where the agitator is very closely disposed to the tank surfaces. However, it is customary to operate the agitator at approximately four times the speed of the tank, relative to its revolutions or r.p.m. which causes the agitator to sweep past the inner surfaces of the tank and create some mulling .action. This, of course, helps mull out larger particles and makes the work required of the disperser easier and, therefore, the overall mixing action quicker. This, of course, does not say that the disperser could not be used with another type of agitator Where material is moved radially in the tank and where mixing is accomplished less efiiciently. As mentioned previously, the rotation of the tank feeds material to the disperser. Since, the diameter of the disperser is much smaller than the diameter of the tank, it requires the material to be brought to it in order to be able to perform efficient work upon the material. Also, since the materials with which it is normally used, are such that at least in one phase of their mixing (this is true even in materials which finish up in a soft state), go through a heavy dry state, it is necessary that, in order to go beyond this point, the material be fed to the disperser so that it can break this dry material down and thoroughly incorporate the mixing vehicle.

The present novel combination of elements produces a machine which is not limited to use with materials having good flow qualities but rather may be used with materials with negligible or very poor flow qualities, thus greatly broadening the usefulness of the present mixing device.

The wall 45 of the aperture 41 in the bottom ring 34 is preferably, inclined outwardly and downwardly as shown at 46 in FIGS. 5 and 6 to facilitate passage of the material through said aperture and into the space between the impeller and the bottom wall of 'the container 3 which is the mulling zone A. The embodiment in FIG. 7 does not have the bottom of the wall 45 of the aperture 41 inclined but vertically disposed throughout.

As heretofore described it has been found that in producing ink it is normally required that such material be processed in two steps; the first being mixing, and the second, milling. After the material is mixed, it is normally taken to a roller mill where it is run and re-run. With soft inks a minimum of two runs in a roller mill are usually required, following mixing. With heavier bodied ink, some plants will make four to six runs through a roller mill following mixing. It has been found that the device of the present invention is accomplishing a processing function which herebefore has been a roller mill function rather than a mixer function, in other words, due to the excellent mixing characteristics of the present novel construction which enhances wetting and dispersing of the material a 25 to 50% reduction in the number of mill passes is possible over standard mixing equipment. Since roller mills are expensive and require constant attendance by well paid, skilled personnel, the milling operation itself is the most expensive operation in the processing of printing ink. Overhead rate for mixing operations are usually A to /3 that of the milling rate and with the device of the present invention the reduction in the number of mill passes has proven to be a real saving in both cost and time.

The container in the mixing device shown is rotated,

and its rotation increases the hydraulic shear and impinging force upon the components being mixed. However, while the impeller may be used with non-rotating containers to achieve the results heretofore discussed, a rotating tank is preferred.

It will be understood that there may be various changes in details of construction without departing from the spirit of my invention, and, therefore, I claim my invention broadly as indicated by the appended claims.

Having thus described my invention, what I claim as new and useful and desire to secure by United States Letters Patent is:

1. In combinaton with a container having an inner bottom surface, a dispersing device for intimately commingling components into a homogenous mass, one of which components is a liquid, comprising an impeller eccentrically mounted within said container and having a ring with an open central aperture, means mounted on said impeller causing said components to be mixed to flow through said central aperture, said ring having a bottom surface disposed closely adjacent the inner bottom surface of said container, means for rotating said impeller, said bottom surface of said ring being substantially parallel to said inner bottom surface of said container, said ring having a plurality of projections forming substantially vertical slots substantially uniformly spaced circumferentially in its outer peripheral edge, said projections having their opposite side walls transversely disposed in a generally radial direction to the axis of said ring and extending substantially parallel with said ring axis, whereby said projections produce hydraulic shear in said components.

2. The combination of claim 1 in which the impeller ring is suspended from a spindle engaging member of less diameter than said ring, and said first mentioned means comprises spaced-apart arms which are outwardly and downwardly inclined.

3. The combination of claim 2 in which the edges of the arms are beveled for directing flow of the the materials through the opening of the impeller ring.

4. The combination of claim 1 in which the recesses are generally rectangular in shape to provide two spaced transverse side walls for each recess.

5. The combination of claim 1 in which the bottom edge of the bottom ring opening is beveled.

6. The combination of claim 1 including a spindle fitted thereto by being inserted within an opening in the top ring.

7. In combination with a container, a dispersing device for intimately commingling components into a homogenous mass, one of which components is a liquid, comprising an impeller eccentrically mounted within said container and having circumferentially spaced apart downwardly extending legs, a ring with an open central aperture connected to the lower ends of said legs, said legs being contoured to cause the components to be mixed to be propelled inwardly and downwardly through said open central aperture, said ring having a plurality of projections forming substantially vetrical slots substantially uniformly spaced circumeferentially in its outer peripheral edge, said projections having their opposite side walls transversely disposed in a generally radial direction to the axis of said ring and extending substantially parallel to said ring axis, said ring having sufiicient bottom area adjacent said central opening and being disposed sufficiently close to the inner bottom surface of said container to produce a mulling zone between said ring and said container bottom whereby the aggregates of the components to be mixed are mulled out and said components to be mixed are placed under compression thereby producing a pumping action to move said components downwardly through said central aperture, thereby causing said side walls to impinge and further mull the components to be mixed.

8. The combination of claim 7 including means for rotatably mounting the container.

7 8 9. The combination of claim 7 including a cover for 2,592,334 4/52 Reiffen 259-84 the container through which the dispersing device is 2,651,581 9/53 Courtney 25985 X mounted. 2,657,911 11/53 Nicholls 259-85 10. The combination of claim 9 including a conventional mixer for the container also mounted through the 5 FOREIGN PATENTS 607,392 8/48 England.

container cover.

' 1,151,512 4/56 France.

References Cited by the Examiner UNITED STATES PATENTS CHARLES A. WILLMUTH, Primary Examiner.

2,013,247" 9/35 Nash 259 134 LEO QUACKENBUSH, Examiner.

Claims (1)

1. IN COMBINATION WITH A CONTAINER HAVING AN INNER BOTTOM SURFACE, A DISPENSING DEVICE FOR INTIMATELY COMMINGLING COMPONENTS INTO A HOMOGENOUS MASS, ONE OF WHICH COMPONENTS IS A LIQUID, COMPRISING AN IMPELLER ECCENTRICALLY MOUNTED WITHIN SAID CONTAINER AND HAVING A RING WITH AN OPEN CENTRAL APERTURE, MEANS MOUNTED ON SAID IMPELLER CAUSING SAID COMPONENTS TO BE MIXED TO FLOW THROUGH SAID CENTRAL APERTURE, SAID RING HAVING A BOTTOM SURFACE DISPOSED CLOSELY ADJACENT THE INNER BOTTOM SURFACE OF SAID CONTAINER, MEANS FOR ROTATING SAID IMPELLER, SAID BOTTOM SURFACE OF SAID RING BEING SUBSTANTIALLY PARALLEL TO SAID INNER BOTTOM SURFACE OF SAID CONTAINER, SAID RING HAVING A PLURALITY OF PROJECTIONS FORMING SUBSTANTIALLY VERTICAL SLOTS SUBSTANTIALLY UNIFORMLY

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