US2840358A - Mixing device - Google Patents

Description

June 24, 1958 l o 2,840,358

MIXING DEVICE Filed May 24, 1957 unnm n INVENTOR. ANTHONY Aer/N0 F54 /M4%MJ4 This invention relates to agitating devices and particu larly to a rotating stirrer" for viscous or semi-solid materials.

Condu'cive to a better understanding of theinvention it may be well to point out that it is' common practice to use motor driven stirring devices, having a plurality of spaced parallel discs secured to a rotary shaft. The spinning discs are supposed to suck the liquid to be mixed inward and then throw it outward due to the action of the spinning edges of the discs. 9

However in the mixing of viscous liquid such as heavy petroleum products, greases, tars, soaps, etc., a great A collar"13.i s welded to the shaft 11 immediately above its thre'adejd end' .29. And a lower bar 14 is swivelly motiuitedbn"the shaft 11, againstthe lower face of the 'collar l3. The bar 14 is held in place by a nut 30. The bar 14 also has two holes 17 and 18, similarly countersunk as those of the upper-bar 12, and similarly spaced. The two bars 12 and 14 act as a yoke to support two, headed impeller shafts 19 and 20 which are mounted in the holes 15, 17 and116, 18, respectively. Each shaft 19 and has a threaded lower end and a semi-spherical head'21, and 22, respectively, adapted to seat in theholes 4 and 16,.respectively, of the upper bar 12. The shafts frictional drag is exerted by the viscous materials on the their center of revolution, whereby intersecting fluid flow.

lines are created which act to reduce all vortex forming forces to a minimum. a

Another object is to provide a device of the type stated whose discs are free to rotate on their axes, so as to afford minimal frictional opposition to the movement of fluid passing therebetween.

A further object is to provide a device of the type stated that is capable of functioning effectively in liquids of any viscosity, and even in semi-solids.

These and other objects of the invention will become Furthermore, with such viscous liquids the inter-,

apparent from a reading of the following specification v and claims, together with the accompanying drawing, wherein:

Figure lis a perspective view of a mixing device made in accordance with my invention;

Figure 2 is a side elevation of the same;

Figure 3 is an exploded view of the device;

Figure 4 is a side elevation of an alternate form of the device having conically shaped discs: and

Figure 5 is a top plan view of one of the conical'discs.

Referring more particularly to the drawing there is seen the mixer head that is the subject of this invention broadly indicated by reference numeral 10.

The device comprises a driver shaft 11, adapted to be connected directly at its upper end to a driving motor, not illustrated, or to a flexible motor driven shaft.

The bottom end 29 of the shaft 11 is threaded, as seen in Figure 3. 1 V

A flat bar 12 is welded to the shaft 11. The bar 12 has two spaced holes 15 and 16, at the ends thereof. Each hole is countersunk at the top and bottom to form a semicircular seat.

19 and 20 are held in place by means of nuts 25 and 26 which bear against semi-spherical washers 23 and- 24 which are seated in holes 17 and 18,-respectively, of the lower bar 14.

Reference numerals 27 indicate a plurality of flat discs which are co-axially mounted on .the impeller shafts 19 and are-spaced apart in parallel relation by collars 28;. 'Boththe discs 27 and the collars 28 are free to rotate on impeller shafts 19 and 20.

In assembling the mixer head 10, the lower yoke bar 14 is swivelled with relation to the upper yoke bar 12 until the two impeller shafts 19 and 20 assume the angular inclination to each other and the shaft 11, as illustrated in Figures 1 and 2. The nut 30 is then tightened, as are the nuts 25 and 26, thus locking the various elements together into a rigid structure. 7

In operation, it will be evident that upon rotation of the shaft 11, the two impeller shafts 19 and 20 together with their co-axially supported discs 27 will revolve about the shaft 11 in a plane angularly inclined to its center of rotation. At the same time the several discs 27 are free to rotate on their own axes, that is the longitudinal axes of the impeller shafts 19 and 20, upon which they are mounted. a 1

When the device 10 is immersed in a viscous fluid it will be evident that the spaced and parallel discs 27 on each impeller shaft 19 and 20 will cut angularly opposed paths through the mixture, whereby all flow lines of the mixture created by one set of discs will run counter to those created by the other set of discs. These opposing flow lines effectively counteract any tendency for a vortex to be formed, thereby rendering the mixing action more efficient than that attainable with any prior art devices.

Furthermore it will be apparent that any frictional drag between the disc surfaces and the fluid being mixed will cause the discs to rotate freely on their axes, thus facilitating the break-up and mixing action of the discs, since their rotation acts to facilitate the flow of the fluid into and out of the spaces between them.

The diameter and spacing of the discs 27 may be varied to suit fluids of varied viscosity. The greater theviscosity thegreater the spacing and diameter of the discs.

Similarly the angular inclination of the impeller shafts 19 and 20 may be adjusted by swiveling the lower yoke bar 14 in relation to the upper yoke bar 12.

An alternate form of the device is illustrated in Figures 4 and 5 wherein the discs 31 are conical in shape. Each disc 31 has a flat seat portion 32 at its apex which bears against the spacer collars 28. The conical surfaces are set at an angle of between 15 and 20. These collars and discs are also mounted free on the impeller shafts as are the flat discs 27. It has been found that in some applications, such conically shaped, freely rotating discs will effect a better mixing action.

The device as described provides a mixing head having an eccentric effect, while at the same time being perfectly balanced with relation to its center of rotation. Furtherand tacky compounds.

It willfnow be clean-thatthere is provided a 'devicr which accomplishes the objectives heretofore set forth While'the invention hasbeen disclosed in its preferred form; it is to be understood that the specific embodiment of fiuid materials to be'mixed, comprising in comb iiia tion, a drive shaft having a' yoke mounted thereon including two spaced impeller shafts mounted laterally, each side of the drive shaft,. at an angle liter te and ash other, and a plurality of coaxiaL paiallel.fahdzfumformly spaced conical disc impeller.lefnents mounted on each of said impeller shaftsgeach ofisaid cohicaldisc eleinents being independently free to'rotateion its ir'npelle'r" shaft.

2. Mixing apparatus adaptedto be immersedLin-a body of fluid materials to be mixed, comprising' in'combination, a drive shaft having a yoke mounted thereori'including two spaced impeller shafts mounted laterallyo'f each side of the drive shaft, at'an angle theretoand tofeach other, and means for varying the angular disposition of the impeller shafts between adjusted positions, and a pluralityof' coaxial parallel and uniformly spaced fiat disc impeller elements mounted on each of said impeller shafts; each of said disc elements being independently free to rotate on its impeller shaft. v

3. Mixing apparatus adapted to -be immersed in a body of fluid materials to be miq ed cgmprising in combination a drive shaft having a yoke-mounted thereon including two spaced impeller shafts mounted laterally of each side of the drive shaft,,at an angle thereto and to each other, and means for varying the angular disposition of the impeller shafts between adjusted 'positions and. a plurality of coaxial, parallel and uniformly spaced conical disc impeller elements mounted on each of said impeller shafts; each of said conical, disc elements being independently free to rotate on its impeller shaft. 1

References Cited in the file of this patent 5- UNITED STATES PATENTS"

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