US2890869A

US2890869A - Mixing device

Info

Publication number: US2890869A
Application number: US546681A
Authority: US
Inventors: Sohn Hermann
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-11-14
Filing date: 1955-11-14
Publication date: 1959-06-16
Anticipated expiration: 1976-06-16

Description

June 16, I959 I H. SQHN 2,890,869

MIXING DEVICE Filed Nov. 14,1955 4 Sheets-Sheet 1 I v a 20 19 72" L 27 lnren/or:

H. SQHN MIXING DEVICE June 16, 1959 4 Sheets-Sheet 2 Filed NOV- 14. 1955 H. SOHN MIXING DEVICE June 16, 1959 4 Sheets-Sheet 3 Filed Nov. 14.11955 I I II IIIM W HH I nWIII I I I I I IV. I I III II IIIII 1!! g R m an. IE I 1 I. Q Q I we 7 m m H. SOHN MIXING DEVICE June 16, 1959 Filed NOV. 14. 1955 4 Sheets-Sheet 4 United, States Patent 2,890,869 MIXING DEVICE Hermann Sohn, Dusseldorf, Germany Application November 14, 1955, Serial No. 546,681

4 Claims. (Cl. 259-85) This invention relates to a rapid mixing device consistmg of a rotatable mixing drum and one or a plurality of 'ice Depending upon the nature of the material to be mixed and upon the purpose for which it is to be used, particu- I 9 larly when a triturating elfect is to be produced, it is mixing tools or the like arranged within the mixing drum ,In known devices of this kind the mixing tools are an ranged eccentrically with respect to one or a plurality of main-shafts of the mixing drum and usually consist of rods, flat bars, plates, shovels, or baskets formed from wires arranged at a suitable distance fromthe shaft of the mixing tool.

Although machines of this known kind are usually thought to work satisfactorily, there frequently is the drawback. that devices of this type are suited only for certain purposes, for example the mixing of coloring v matter, artificial materials or the like, but can be used for other purposes, for example the compressing, granulating, polishing and clipping of surfaces, etc. of one. or

necessary to reduce the width of the gap (distance) between the periphery of the mixing or stirring tools and the inner surface of the mixing drum; The width of the gap will then preferably be between 1 to 0.2 mm.

The alteration of the width of the gap will then simultaneously result in an alteration of the angle of engagement, wherein by the angle of engagement is to be understood the angle formed between the tangent drawn atthe I point of shortest distance of the drum from the'mixing 11:00]. and the tangent extending from the same point to the periphery of that mixing tool.

This angle is of particular importance for the How of the material to be treated into the gap formed between the drum and the mixing tool and in whose (the gap) immediate proximity the material is subjected to the highest effect of the mixing tool or mixing tools.

According to the invention the mixing tools are so I devised and arranged within the drum that they can easily I be exchanged either through removal of a flange, or.

. through separation into several parts and be replaced 'bY aplurality of materials only at a considerable loss of.

time.

The inventionhas for its object to devise a machine by means of which also different kinds of work ing operations can be performed, such as the mixing and shaking up of materials, the trituration of coloring matter or the like, or the compressing or granulation of substances or mixtures. At the sametime the mixing device is so constructed, that the time or energy required for the performance of certain working operations can be reduced.

Another .object ofthe invention is to achieve with the device. animproved distribution or ,trituration than has been possible hitherto by means of known devices, so

that vastly improved products as well asnovel types of products can be obtained. I I

According to the invention the mixing device is pro vided with a rotating dnum dimentioned in such a waythat its largest diameter is considerably, larger than that, of the mixing tool, but at least twice as large. as the latter, whereby the shortest distance from thefperiphery of the mixing tool tothe inner surface ofthe mixing drum is equal to or smaller-than diameter of the drum the square root of the largest 3 According to another feature of the invention the mixing deviceis so constructed that the shortest distance from the periphery of the mixing tool to the inner surface of the mixing drum is adjustablewithin the limits from 0 to the aforementioned maximum measure, whereby the adjustment may preferably be effected through an eccentric rotational displacement of the bearingsof the shaftof the mixing tool. I

The first mentioned feature of the invention produces the result thatmomentarily only a small quantity of the material enclosed in themixi ng device is subjected to the mixing treatment, while the bulk of the material is located in non-operative position. This r endersit possible (as was accidentally found out) that the mixing tool arranged in a mixing drum of a capacity of between 20 ential speed of, for'exampl 1 0-5 1 to20,000' liters'can be driven at a"maxim um circumfer other types of tools. An elastic packing ring serves 'as a means to close up thelmixing tool toward the outside in air-proof and dust-proof fashion, whereby a valve or filter serves as a means to regulate the internal pressure with respect to the outside pressure. For gases, liquids and pastes the packing means are of the known type.

The easy exchangeability II is important if the mixing device is to be used for several purposes, for example the shaking up. and, mixing, compression and granulation. I For certain purposesand materials specific tools or coni-, binations of tools are employed, whereby throughj reversal'of thedirection of rotation of the; mixing ,tool or tools or of the drum the function of .the tool or toolsfis changed.

The mixing drum is rotatable in a manner known per se and rotates about an axis which, in dependence upon T the dimensions of the device, does not coincide with the axis ofrotation of the mixing tool, whereby according to the inventionthe speed of rotation of themixing drum 1 h and of the mixing tool are both absolutely as well. as ela- "tively with respect to each other regulatable, reversible and independent, ofeach other.

Because offthese poss1bilities the device is suitedfor many diflerent purposes. It is for instancepossibleito f successively carry out several working operatiohs, for ex- I ample the polishing of the original material, first, at low I rotational speedand, then, at increasing rotational speed of the mixing tool; through admixture of other'substances f:

admixed if, required at timed intervals;yto' compress through reversal ofqthe direction of rotation; or to change 1. the material physically or chemically through therrnic treatment of thematerial. FQr this; purpose theiinner 1 surface of the drum may be coated with a chemically neutral substance. Moreover, for .the construction of. the mixing tool and the other elements such materials may be employed which are indifferent to the substances to be treated, or which produce a catalytic effect upon the substances to be treated.

The' invention further contemplates to feed orinsert into the interior of the drum via a hollow journalof latter spraying means or aerating means, or other means."

Patented June 16, 1959 These means may be of different types and have in each case for their object the treatment of the material and/ or the control of the mixing process.

Additional features and advantages of the invention will be understoodfrom a. consideration of the following detailed description taken in connection with the accompanying drawings, forming a part ofv this specifica tion and inwwhich several embodiments of the invention Fig. 4 is a longitudinal sectional view ofone of the journals of the mixing device as well as of the bearing for the journal, and of the means for feeding cooling and heating means via the journal into the drum and for discharging them fromthe drum;

Fig. is a fractional view, partly in section, of the mixing tool and of the bearing means for the latter;

Fig. 6-is a view of a modified form of construction of the mixing tool;

Fig. 7 is a view of another modified form of construction of the mixing tool in which the effect produced by the tool is changed through reversal of its direction of rotation;

Fig. 8 is a view of still another modified form of construction of the mixing tool operating with a plurality of different mixing and treating means;

Figs. 9 and 9a are a side-view and fractional front-view, respectively, of a mixing tool consisting of two halves;

Fig. is a view of a mixing tool having a plurality of stirringplates or pins tangentially secured to a shaft.

Referring now to the drawings in detail, the reference numeral 1, in the form of constructionrof Fig. 1 designates the mixing drum having the mixing tool 2 rotatablysupported in the flanges 3. The shaft 4 carrying the mixing ;tool is-provided with packing means 5 and carries on one side of the drum a driving pulley 6 driven in this embodiment from a loose V-belt sleeve 7 loosely mounted on the journal 8. The journal 8 is rigidly secured to the wall 9 of the mixing drum 1 and rotatably supported in a bearing 11 mounted on a support 10. Fastened on or at the .support 10 is a motor 12, whereby the V-belt pulley 14 of the motor 12 drives the sleeve 7 and consequently also the mixing tool 2.

In addition to the journal 8 the mixing drum 1 is provided with a journal 16 rigidly secured to the side-wall vofthe drum and rotatably supported in a bearing 17 mounted on a support 18 on the right side of the device.

On the side of the bearing 17 extending away fromgthe mixing drum 1 the journal 16 is provided with a coupling 19 connecting the journal 16 with a gearing, for example a .worm gear 20 driven from a motor 21.

A counter weight 23 for the mixing tool 2, as well as a valve 23' for the regulation of a desired'internal pressure, for example a partial vacuum, or a pressure above atmospheric, or for the leveling of the internal, pressure p with respect to the external pressure, are provided at the side-

walls

9 and 15 of the drum 1, although these means Z'the mixing tool 2 as well as the mixing drum 1. are drivenonly from one side ofthedevice, whilefrom the iotherside of the machinerthe heating or cooling means are admitted into the drum. For purpose the device is provided with double walls, ie the

inner walls

9, 15 and the

outer walls

24, 25.

The rotatable journal 26 is at one end rigidly secured to the drum 1. On the journal 26 is loosely mounted the sleeve 7 which is driven in the same way as already described for the form of construction of Fig. 1. The rotation of the drum is effected via the journal 26, whereby in this case the gearing 19 to 22 is fastened on or at '1 the support 10 on the left side of the device.

of differently sized diameters.

In this form of construction the mixing tool 2 is regulatable and adjustable regarding its direction as well as speed of rotation by means of the gearing 13, while the drum is regulatable and adjustable by means of the gearing 22.

In a special form of construction the drum 1 is provided with a filling funnel 1a shown in Fig. 2 merely in dotted lines.

The feeding of the cooling means into the drum and the discharge of the cooling means from the drum is effected in the embodiment of Fig. 2 via the journal 27 7 (see Fig. 4) which at 28 is supported on the support 18 in a slide bearing 29. The journal 27 is provided with a bore 30 which is closed up at the end facing'the Wall of the drum by a plate 31. A central pipe 32 axially positioned in the bore 30 extends at 33 at a right angle through a radial bore 34 in the journal 27 and the flange 35. A bore 36 radially extending with respect to the bore 34 but offset from the latter receives a branch pipe 37 which is tightly secured in the journal 27 through screw connection. It will be seen, therefore, that both of the pipes 32 and 37 rotate together with the journal 27. Fastened on the support 18 beside the bearing 28 is a supporting member 38 which projects beyond the end 39 of the journal 27. Provided in the hollow annular chamber of the supporting member 38 surrounding the end of the journal 27 are packing means 41 which with the aid of a sleeve 42 and screws 43 are secured in packing position. The sleeve 42 is further provided with a, passage 40 through which projects the end of the central pipe 32 which at 44 is likewise surrounded by packing In Fig. 3 the reference character d designates the diameter of the mixing tool or the like, while D denotes the inner Width of the mixing drum. According to the invention the ratio of the diameter D of the drum to the diameter d of the mixing tool is at least 2:1, whereby the shortest distance h from the circumference of the mixing tool to the inner wall of the drum should not be longer than Denoted by e is the radius of the eccentric circle having its center located in the axis of rotation of the drum. K and K are two mixing tools point of'shortest distance from the drum to the mixing tool, extending from the inner surface of the drum and touching the peripheries of the differently sized mixing.

a specific value, as otherwise the possibility exists-that 1 the engagement of the material will either be. seriouslyreduced or completely annulled.

In the same way there existsa best value for theqangle of engagement for a specific material.

The tangents from the It is possible, for example, to maintain, when the distance h decreases, the same angle of engagement, when the diameter d of the mixing tool likewise decreases, or vice versa.

The drum 1 rotates in the illustration of Fig. 3 about an axis extending through P, so that the material to be mixed is subjected in the area of the mixer to a relative speed a, which amounts to whereby n designates the number of revolutions of the mixing tool, while n designates the number of rotations of the drum. The plus and minussigns have to be regarded as signs of the direction of revolutions. In case of large numbers of revolutions of the mixing tool the relative speed is of secondary importance. The rotation of the drum is chiefly intended to produce a large whirling action in the material. The number of revolutions of the drum may be adapted to special conditions, whereby the accelerations caused by the peripheral speed are usually not bigger than the accelerations caused by the force of gravity.

According to what has heretofore been explained there result for a mixer as disclosed in the present invention, departing from a diameter D=800 mm. for the mixing drum, the following peak values:

airare tang 0.55 -29 Furthermore, the peripheral speed of the mixing tool is 10 m./s. and the number of revolutions of the drum 12 r.p.m., there result n 12 r.p.m. e h= 0.372 m. and, therefore, for the relative speed 7 H for rotation in the same direction u (dn F2en 9.6 rn./s., for rotation in opposite d1reet1on-10.5 m./s. Within the limits given in the example the influence of the relative speed, therefore, amounts to 10%.

The mixing tool is particularly devised for the mixing and trituration of various types of pulverized materials, and for that reason provided with bar-shaped or flat mixing members. Figs. 5 and 6 show a mixing tool consisting of a shaft 49 having mounted thereon at least two supporting members, for example plates 50. Arranged between and supported by the two plates 50 are a plurality of bars 51, which in the embodiment shown in the drawings are of circular cross-section, and which for special purposes rotatably support roller-like members 52.

It is further possible to employ instead of the plates 50 radially extending pins 50 adapted to carry the bars 51. The plates or pins 50 are directly fastened to the sleeve 53 which may be secured in its position on the shaft 49 by means of a wedge against displacement in axial direction. The sleeve 53 is provided with a collar 54 adapted to bear against packing means 55, whereby the necessary compressive pressure is exerted by a sleeve 58 shiftably positioned in the flange 56 and acted on by a spring 57. A nose 59 provided on the sleeve 58 is guided in a groove 61 provided in the flange-collar 60, safeguarding in this way the sleeve 58 against rotational displacement. The sleeve 58 is surrounded by packing means 62 arranged in an annular recess of the flangecollar 60. The pressure exerted by the spring 57 is adjustable by means of a tension ring 64. The shaft 49 has both of its ends (only one end having been shown in 6 the drawings) supported in a self-aligning roller bearing 65 accommodated in a cap 66, whereby the cap 66 is secured to the flange 56 in known manner by means of screws 67. By means of an annular collar 69 provided with packing means 68 the shaft 49 is tightly closed up, so that the lubricating grease introduced via the bore 70 cannot run out.

On one ofthe ends of the shaft, for example at 71, is fastened by means of a wedge 72 and a plate 73 a driving pulley 6.

As shown particularly in Fig. 5 the shaft 49 is eccentrically supported with respect to the flange-collar 74 of the flange 56, whereby the radial distance from the central axis of the shaft to the flange-collar is m or n, respectively. This makes it possible to adjust, through rotation of the flange 56, the distance h within the limits of the eccentricity n-m.

According to Fig. 6 the mixing tool may be provided with a plurality of roller-like members 52 which are rotatably supported on supporting bars 51. The rollerlike members 52 are then provided at their ends with bearings 55 preventing the material to be mixedfrom entering into the enlarged inner space of the roller-like members 52. Through proper selection of the diameter d of the roller-like members 52 it is possible to adapt the gap or distance it (see Fig. 3) to requirements. The construction is then devised in such manner that an easy exchange of the roller-like members 52 for various purposes'of use is thereby enabled.

According to Fig. 7 the mixing tool-p-which in this case changes its function through reversal of its direction of rotation-consists of wings or plates 75 and 78 having their free ends curved in a possible direction of rotation and which may be radially secured to the shaft 49.

If the mixing tool of Fig. 7 rotates in the direction indicated by the arrow 79 the tool will whirl up the material and shake it up. If, on the other hand, the tool rotates in the direction of the arrow 80, then a friction effect or grinding effect is produced between the bottom 81 and the material to be mixed.

According to the embodiment illustrated in Fig. 8 the mixing tool consists of a plurality of different groups of tools, i.e. the. groups 83, 8'4 and 85, whereby the groups 83 and 85 consist each of a knife-carrying shaft 86 and of a perforated plate 87, while the tool 74 consists of a pair of turning shovels.

In Figs. 9 and 9a the tool consists of two

halves

90 and 91, whereby the two halves are secured to each other by means of screws 92 traversing projecting portions of the

lateral plates

90 and 91. Tightening of the screws 92 causes the walls of the opening 93 to rest snugly against the shaft 49. The walls of the opening 93 may be provided with means for example key-ways 94 and wedges) securing the tool in non-shiftahle position on the shaft.

In Fig. 10 the tool consists of two plates 95 tangentially secured to the shaft 49. It is understood that instead of the two plates also a larger number of plates may be employed.

However, the invention is not confined to the use of mixing tool as hereinbefore described. It is also possible to employ other types of tools, for example stirring or agitating tools, fork-shaped prongs, plates of screw like formation, and other tools adapted for the adjustment of its diameter with respect to the distance h.

In the embodiment shown in Fig. 2 the journal 26 is provided with a hollow inner passage. This passage is chiefly intended for the introduction therethrough into the interior of the drum of a shovel-like tool 96 fastened at the end of a rod for the purpose of taking out of the drum, while the latter is in operation, samples of the material in the process of treatment. But the passage may also be used as a means for the aeration of or for the removal of the air from the drum, or for the feeding or insertion into the drum or into the space between to be.adrnixed,..a liquid, .a chemical reagent or the v like.

The invention also provides the mixing device withinthe mixing .chamber with stationary or movable scraping means for the material. Furthermore, themixing device is provided at all important places with measuring tools, indicating the temperature and the interna1pres-- sure within the mixing drum, within itsjacket or at otherplaces.

What I claim as new and. desireto secure by Letters Patent of the United States is:

1. A-rapid mixing device for thehomogeneous mixing and-trituration of'various types vof pulverized materials, comprising a rotary mixing .drurn provided for its rotation with a pair of journals rigidly secured to and axially-.extendingfrom opposite side-Walls of said. drum; a pair of supporting members oppositely positioned on the sides of said drum and provided with bearings adapted for the rotatable support ther'einof the free ends of. said journals; rotary mixing means positioned within said drum and supportedin the side-walls of thedrum eccentricallyto the axis of the. drum; regulatable I driving means for said drum coupled to one of said pair. of journals and adapted'to rotate said drum according to requirements; and additional regulatable driving means for said mixing means likewise coupled to oneof said pair of journals and adapted to rotate said rotary mixing means :at high speed. independentlyof the rotation ofisaid drum, saiddriving means of said drumandsaid additional driving means of said mixingmeansbeing adapted for theadjustment :ofthe directionof rotation as vwell as for theadjustment of the absolute speed .and relative. speed of said rotary drum-and of said rotary mixingmeans.

2. A rapid-mixing device for thehomogeneous mixing andtrituration of variousntypes of pulverized materials, comprising a rotary mixing drumprovided forits rotation with a pair ofjournals rigidly secured tosand. axially extending from opposite-sidewalls of saiddrum; a. pair of supporting members oppositely: positioned on the sides of the drum. and providedwith bearings. adapted. for the rotatablesupport therein of. the free ends of said journals; rotary'rnixing means positioned within said drum and supportedin the sidewalls of the drum eccentricallywto the. axis of theidrum, said rotary .mixingumeans being provided with :adjustable supporting means adaptedfor adjustment without alteration of the diameter..of,..the..mixing means. of a suitable distance of .theperipherytof.said mixing means from the inner surface ofatheidrurmreg ulatable drivingvmeansfor said Tdrum coupled .tosone ot said pair of journals and adapted..to .rotate. said drum according to requirements; and addition al regulable driv ing means for said mixing. means likewise coupled to one of said pair of journals and adapted to rotate said rotating mixing means-at high speed.independentlyeofsthe rotation of-said drum, said driving means of :said. and said additional driving means of said mixing means being adapted for the adjustment, of the. direction ofprotation as well as for.thevadjustmentrof 'the absolute speed and relative-speed of'said rotary.'dr;um -and oft-said rotary mixing means.

3, Arapid mixing device as-speei=fied rinaclaim 2,

whichthe adjustment of thesangleformedbet-weencthe tangent extending from the .point of shortestdistance of the inneri surfaceof the-drum from :the, periphery of-the mixing means to the periphery of the mixinglmea-ns a-nd the horizontal line is effected through rotation -of-said eccentric supporti-nglmeansl of the. mixing means.

-4 A rapid" mixing device as -ispecified in claim 2,-=in which said mixing means consist of a rotatable shaft-wand of a plurality of rectangular plates having one of their long sides tangentially secured tosaid'shaft.

References Citedinthe file of this patent UNITED'STATES PATENTS :Howden Dec. V6, 1955