US 2734728 A
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Description (OCR text may contain errors)
c. K. MYERS 2,734,728
MIXING MILL Filed Feb. 9. 1955 Feb. 14, 1956 Zhwentor (M005 K MYERS (Ittorneg United States Patent MIXING MILL Claude K. Myers, Bell, Calif.
Application February 9, 1953, Serial No. 335,689
Claims. (Cl. 259107) This invention relates to a mill for mixing viscous materials such as used, for instance, in the paint industry, and has particular adaptability for mixing ingredients that are difiicult to put into solution, for example, resins.
An object of the present invention is to provide a mill structure that obviates the use of bearings submerged in the material being mixed to, thereby, eliminate a source of trouble and materially increase the life of the structure.
The present mill, being of the rotary type, and such mills usually creating centrifugal displacement of the materials being mixed therein, it is another object of the invention to provide a mill construction that counteracts centrifugal force and, thereby, insures improved mixing of the materials by more efficient retention of physical contact of the materials with the mixing elements of the mill.
A further object of the invention is to provide a mill that produces a strong and eflicient downward thrust on the materials being mixed while, at the same time, re stricting the outlet fiow from the mill to provide improved admixing of the materials by the mechanical pressure resulting from the counteracting opposed forces resulting from such downward thrust and restriction.
The invention also has for its objects to provide such means that are positive in operation, convenient in use, easily installed in a working position and easily disconnected therefrom, economical of manufacture, relatively simple, and of general superiority and serviceability.
The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description. However, the drawing merely shows and the following description merely describes, one embodiment of the present invention, which is given by way of illustration or example only.
In the drawing, like reference characters designate similar parts in the several views.
Fig. 1 is a vertical sectional view of a mill according to the present invention.
Fig. 2 is a top plan view of a rotor plate as used in said mill.
Fig. 3 is a top plan view of a stator plate operatively associated with the rotor plate of Fig. 2.
Fig. 4 is an enlarged fragmentary plan view of a rotor and stator plate assembly, the plates varying from those shown in Figs. 2 and 3 only in that more material-passing slots are provided therein.
Fig. 5 is a similar view of a rotor and stator plate assembly that is arranged alternately with the assembly of Fig. 4.
The mill that is illustrated comprises, generally, a housing 10, a hopper 11 to feed material to said housing, an outlet 12 from the housing, a regulatable restriction 13 in said outlet, mixing means 14 within the housing to intermix materials fed thereinto by the hopper and discharge the same into the outlet, a rotor shaft 15 to drive means 14, and means 16 to adjust said shaft and the mixing means, as desired.
Patented Feb. 14, 1956 The housing 10 is provided with a cylindrical wall 17 and with upper and lower walls 18 and 19, respectively. A jacket 20 for a cooling medium is provided for wall 17 to effect heat exchange with the materials being acted on by mixing means 14.
The hopper 11, by means of inlet 21, opens into the top of housing 10 and gravitationaly feeds materials to said housing.
The outlet 12 is shown as a simple discharge pipe, and the restriction 13 is shown as a gate valve 22 in which the gate 23 extends in the path of materials moving in said outlet and is adapted to be regulated, as by handle 24, to vary the effective size of the outlet. The restriction thus provided creates back pressure on the material being discharged, said pressure manifesting itself in the interior of housing 10.
The mixing means 14 comprises a plurality of stator plates 25 fixedly mounted in housing 10 and mutually spaced from each other by peripheral flanges 26, the lowermost stator plate being located by an annular shoulder 27 provided in wall 17 and a spacing collar 28 being interposed between the uppermost stator plate and housing wall 18. In this manner, a chamber 29 is provided in the housing below the mixing means 14 and opening into outlet 12, and a chamber 30 is provided above said mixing means and receptive of material from hopper 11. Accordingly, the flanges 26 of the stator plates serve to space the plate parts 31 from each other substantially as shown. Also, said stator plates are each provided with a central hole 32 in clearance relation to shaft 15 which extends through said holes.
The mixing means 14 also comprises a plurality of rotor plates or vanes 33 that are fixedly mounted on shaft 15 by means of a key 34 and the same are spaced from each other by collars 35, the spacing being the same as that between plate parts 31 of the stators. 'A shoulder 36 on the shaft locates the uppermost rotor vane, and a retainer washer 37, held in place by a bolt 38, engages the lowermost rotor vane and locks the assembly of the vanes and spacing collars 35.
The stator plates 25 and the rotor vanes 33 are alternately arranged, the latter occupying the spaces 39 that are defined circumferentially by flanges 26 and, above and below, by stator plate parts 31. It will be understood that there will be at least one rotor vane for each stator plate, although, as shown, an additional rotor vane may be provided beneath the lowermost stator plate.
Each stator plate part 31 is provided with a set of slots 40 that are angularly rather than radially directed, being tangent to a circle generated about the center of said plate part. Each rotor vane 33 is provided with a similar set of slots 41 except that the angle at which the latter slots are directed is opposite to that of slots 40 of the stator plate part. It will be seen, therefore, from Figs. 4 and 5, that the slots of each rotor 33 and stator 25 intersect.
Assuming clockwise rotation of the rotor, as indicated by arrow 42, if the slots 41 are at a tangent angle in one direction, as in Fig. 4, said slots, as vane 33 rotates, wipe inwardly toward the center and from the outer ends toward the inner ends of slots 40 in the stator. In other words, the outer ends of slots 4t) and 41 meet first and, thereafter, the transversely angled slots intersect at points successively nearer the center of rotation. It follows, then, that any material passing through rotor slots 41 is pressed into stator slots 40 and, at the same time, is forced toward the center of rotation of the rotor vanes. If the slots 41 are at a tangent angle in the opposite direction, as in Fig. 5, said slots, as vane 33 rotates, wipe outwardly away from the center and from the inner ends toward the outer ends of slots 40 in the stator. Consequently, any material passing through rotor slots 41 is pressed into the gaged with the shaft.
--inFig.'4,"the materialpassing'throughsaid vanes and -the*'s'tators operatively 'associated therewith is thrust in an'inward direction. By having-the angular direction of the slots in the second and fourth rotor vanes, as shown in Fig. 5, the material is thrust in an outward direction. By means of this alternate arrangement, regardlessof the number of rotors and stators used, the material passing through themeans 14' is' alternately pressed inwardly and outwardlyrelative to the center of rotation. In the above manner, centrifugal force resulting from high speed rotation'of the rotor is largely overcome and the alternate reversal of movement of the'material improves the admixing engagement of the rotor and stator with the material.
While the slots 40 and 41 may extend directly through the respective stators-and rotors and yet move the material back and forth as above, the pressure on the material will be-as great upward as downward. In order to create a downward pressure on the material so that the same is forced toward the outlet 12, the slots 41 in the rotor 33 are made to be on a transverse angle, as seen best in Fig. 1 and shown also by the dotted lines of Fig. 2. However, with respect to'a clockwise rotation of the rotor vanes, said transverse angle from the top down is in a direction opposite to the direction of rotation. Therefore, lip 43 of each slot 41 leads or bites into the material thereabove and the angular face 44 of each said slot presses the material in a downward direction.
-The transverse-angle of slots 40 is "made-to be opposite to that of slots 41, as shown in Figs. land 3. Consequently, the material delivered by slots 41 is bitten into by leading edges 45 and forced in a downward direction by angular faces 46.
Thus, by having the slots on tangential angles in the rplanes of the rotors'and stators but in opposite directions, and having theslots on opposite transverse angles and with those in the'rotors angled oppositely to the direction of rotation, the material is not only alternately moved outward and inward, but also thrust downwardly toward the outlet.
While considerable pressure will be built up in the housing and particularly in chamber 29, at times it may be desired-to further retard the flow toward the outlet to increase such pressure on the material and improve the admixing resulting therefrom. The restriction 13 can be regulated accordingly.
It will be noted that spaces 39 between stator plates -31 are 'substantially greater than the thickness of rotor vanes 33, enabling moving of said vanes relative to the stators 25 by means of means 16 to vary, as desired, the degree of attrition between the rotors and stators. The
means 16 is shown as a spider or bridge 47 extending across the top of hopper 11 and through which shaft-15 extends, a thrust bearing supported by spider 47, and a collar 48 supported by said bearing and threadedly en- It will beseen that said collar can be adjusted on said threads to shift shaft 15 endwise and, thereby, shift the'rotor vanes on said shaft relative to the stators. A nut'49- serves to lock the adjustment.
7 -It will be understood that-shaft 15 is driven at a desired speed.
While I have-illustrated and described What I now contemplate to be the best mode of carrying out my invention, the construction is, of course, subject to modification'without departing from the spirit and scope of the It" is, therefore, not desired to restrict the *4 invention to the particular form of construction illustrated and described, but to cover all modifications'that may fall within the scope of the appended claims.
Having thus described the invention, what I claim and desire to be secured by Letters Patent is:
l. in a mixing mill, a plurality of spaced stator plates each having a set of through slots tangent to a circle generated around the common center of said plates, the slots in alternate plates being tangent at an angle opposite to the angle of tangent in the plates between the alternate plates, a plurality of rotor varies" on an axis on said common center"and-inalternate arrangement with'the stator plates and eachrespectively operatively associated with one of the stator plates, each rotor vane having a set of through slots tangent to a circle generated around said axis, the slots in each rotor vane being tangent at an angle opposite to the angle of tangent of the stator plate with which the same is associated.
2. In a mixing mill-accordingto claim 1: theslots in the rotor vanes'extending through said vanes at an angle opposite to the direction'of rotationof the rotor plates.
3. In a mixing mill'according to claim 1: the slots in the rotor vanes extending-through said vanes at an angle opposite to the direction of rotation of the rotor'plates and-the slots in the-stator plates extending through said plates at an angle in the-direction of rotation of the rotor vanes.
4. In a mixingmill, a housing, a stator plate carried -by its peripheral edge by said housing, said plate having a set of through slots tangent to acircle generated around a the center of said plate, a driven shaft-having its axis of rotation on-said center, a rotor vane carried by saidshaft adjacent to the stator plate, said rotor vane having a set of through slots tangent to a circle generated around said axis, the latter slots being at a tangenta'ngle that is opporotation on said center, a rotor vanecarried by said shaft adjacent to the stator-plate, said rotor vane having a set of through slots'tangent to a circle'generated around said axis, the latter slots being at a-tangent angle that is opposite to the angle of tangent of the slots in the stator plate, a second stator plate carried by the housing and spaced from the first plate, a secondrotorvane carried by the shaft in the space between the' stator plates, said plate and vane each having'through angularly tangent slots therein, the slots in the-second stator plate being at a tangent angle in the same direction as the tangent angle ofthe first rotor vane, and the slots in the secondrotor vane being at a tangent angle in the same direction as the tangentangle of the first stator plate.
References Citedin the file'of this patent -UNITED STATES PATENTS 989,126 Currie Apr. 11, '1911 1,308,250 Mortensen July 1, 1919 1,794,214 Thurm et'al. Feb. 24, 1931 1,874,079 Black Aug.'30, 1932 1,987,944 Rafton Jan. 15, 1935 2,169,338 Ditto Aug. 15, 1939 2,240,841 Flynn May 6, 1941