US2231421A - Colloid mill - Google Patents

Description

Feb. H, 1941. GlTzENDANNER 2,231,421

COLLOID MILL Filed Jan. 22, 1958 lNVENTOR l A ou/s G/rzsAwA/VIVER K BY i .n

ATTO R N EYS Patented Feb. 11,1941 V 2,231,421

UNITED STATES PATENT OFFICE COLLOID ltIILL Louis Gitzendanner, Richmond Hill, N. Y., as-

signor to Greenwich Machine & Tool Co., Inc., New York, N. Y., a corporation of New York Application January 22, 1938, Serial No. 186,410

15 claims. (c1. iis- 13) The present invention relates to colloid mills therefore, there is provided at the discharge end of both the horizontal and vertical type, and of the rotor, a smooth, continuous arcuate path particularly to the former. which gently` receives the stream of discharged The present application is a continuation in fluid and guides it away from the rotor. The

part of my co-pending application Ser. No. fluid is thus caused to travel along a path which 172,833, filed November 4, 1937. It is the genis very similar to that traversed by it just before 5 eral object of the invention to simplify the conleaving the rotor, and as this curved surface is struction, increase the eiliciency and reduce the free 'from irregularities or obstructions, the liquid cost of this type of apparatus. flows smoothly therealong and is afforded no More particularly, it is an object of the inopportunity to rebound from any part thereof. 10

venton tol eliminate the packing which has it passes over the curved stationary surface, hitherto been necessary for sealing the shaft of 1 in' a more or less spiral stream, its velocity is rethe rotor against the casing of the mill, thereby duced. so that when it meets the edges of the not only simplifying the construction but also OutletA Opening, which, ecccrdingte the inveneliminating a source of frictlonal heat, thus reticrly iS removed from the discharge end of the 15 ducing the power consumption, and avoiding inroter by Such interposed arcuate Path. it does jury to heat-sensitive fluids. other objects and not strike the edges 0f the opening with such advantages of my improved apparatus will be.. violence` as to rebound toward the shaft. The come apparent from the following, more detailed length '0f the guiding Surface Should preferably description thereon Y 4 not beso great that the velocity of the liquid 20 I have found that in prior constructions, a lOWhE Spirally therealcng becomes insuillcieht packing er stumng box about the rotor shaftwas t0 Overcome the forces 0f gravity. for in such made necessary not so much by the normal pres- @Vent the liquid Would drop dOWn from the upf sure of the 'fluid fed to the colloid mill, as by the Der Darts 0f the Surface onto the shaft. peculiar phenomenon of the rebound of the The curved surface upon Which the liquid diS- 25 liquid or paste being treated, upon striking an charges muy take Various fOrmS. It may, for obstruction in its path after being eemrlfuemia` example. represent the inside surface of the projected at the discharge end of the r0t01- The housing of the mill, in which event it is desirable meer of eolleid mills, asis vvell known, is driven that the Shaft be Surrounded by a sleeve exat extremely high speeds and as the liquid or tending from the end Wall 0f the housing, the 30 paste leaves the discharge end of the rotor it discharge Outlet being IOCated at such a dishasa very great momentum due to its high vetance from the rotor, that the free end ofthe locity., The centrifugal force projects the liquid Sleeve lies between it und iShe rctcr, the relatoward the wall of the casing and away from the tionshlp being Such that the rotary Velocity 0f Shaft. However, upon: Striking an obstruction, the liquid does not fall, in the interval between Such as the edge of an'outlef; opening ifi the Wan the rotor and the free end of the sleeve, below of the casing, the stream of liquid rebounds, a that required t0 Overcome thcfclce 0f gravity, considerable part of it apparently striking the 5 that Il@ liquid fallS upon the unprotected Shaft at high speefL This high velocity Stream shaft portion. The curved discharge surface may exerts considerable penetrating pressure against als? tak@ the 'form'.cf u circuler flange arranged 40, the packing, and it is fortlris reason that very adlant t0 the discharge end Of the rotor and tight Stuffmg boxes havemitherto been found spaced from the wall of the housing. In such necessary. l l construction, the discharge opening can be 10 With the object of eliminating the necessity cated behind the flange and the side wall of the for stuffing boxes and similar friction-producing casing `can be disposed Only a Short distance packing, I began a series of investigations on the from the free edge 0f the flange. thereby reducing behavior of the liquid after it leaves the disthe length 0f the apparatus and hence also 0f charge end of the rapidly rotating rotor of the the rOtOr Shaft While ythe Shaft may in this colloicl mill. My observations have led to the construction also be partly protected by a sleeve conclusion that it is important to dispose a comt0 prevent access 0f liquid to the bore in the 50 pletely circular stationary path at the discharge housing wall receiving thel shaft, l have found end of the rotor,` so that the liquid thrown ofi 'such sleeve to be unnecessary, there being no centrifugally by the rotor meets a surface Whose -leakage in spite of the high velocity of disl curvature is approximately that of the discharge charge and the absence of packing. f l end of the rotor. According to the invention, The embodiments of the invention are shown 55 by way of example on the accompanying drawing in which Fig. l is a vertical section through a colloid mill of the horizontal type embodying the features of the present invention;

Fig. 2 represents a transverse vertical section along the line 2.-2 of Fig. l;

,Fig 3 is a partial view illustrating a modified form of the invention; and

Fig. 4 shows in elevation a View of the rotor.

Referring to the drawing, the numeral I0 represents a shaft which is driven at its right-hand end by a motor (not shown) by way of a clutch, shown generally at II, and composed of a metallic disc I2 keyed to the shaft I0 so as to rotate therewith, and ilxcd against longitudinal movement thereon by means of a screw I3. The motor shaft is provided with a similar disc I4 fixed thereto. Coupling pins secured to the discs I2 and I4 pass through aligned openings in the discs and also through an intermediate leather or rubber disc I6. The construction of this clutch forms no part of the present invention and, being known, need not be described in further detail.

The shaft II is supported upon two ball bearings I'I and I8, the inner raceway of the bearing I'I abutting against a shoulder I9, while the inner raceway of the bearing I8 abuts against a shoulder 20 on the shaft. A lock-nut 2| on a threaded reduced portion of the shaftl ID engages the outer face of the inner raceway of the bearing I8 and secures such inner raceway against longitudinal movement relatively to the shaft. The upper raceway is clamped against a shoulder 22 provided in a sleeve 23 by means of a lock-nut 24, which is threaded into the end of sleeve 23. The lock-nut 24 surrounds the nut 2| and the reduced end of the shaft IIJ, but is not in engagement therewith.

The sleeve 23 forms part of or is secured t0 a hand-wheel 25 which is threaded into a circular bore in the supporting frame 26, as shown at 2'I. Upon rotation of the hand-wheel 25 in one or the other direction, the shaft Ill will be moved longitudinallyfor a purpose that will appear hereinafter. "1

The bearing Il is free to move longitudinally within a chamber 28 provided by a casing 29 which may be bolted to the supporting frame 26,

as shown at 36. The casing member 29 is pro vided with a disc-like wall or web 3I which has a central bore 32 through which the shaft passes. The end portion of the shaft is received within a central bore 33 in a rotor 34 of conical shape, as illustrated, the shaft being fixed to the rotor by means of a key 35. The shaft is secured to the rotor also by means of a machine 'screw 36 which enters a tapped hole at the end of the shaft, the head of the screw engaging against a washer 31 which bears against the end of the rotor, the screw and washer effectively closing the end of the bore 33 and preventing passage of fluid through the bore.

The rotor is surrounded by a stator 38 which, as illustrated, may form simultaneously one of the parts of the casing and may be secured to the casing member 23 in any suitable manner, as by means of bolts or screws 36a which enter tapped openings in a radial flange extending from the stator 33, the heads of the bolts or screws engaging against a similar flange on the member 29. The stator casing member 38 is provided with an extension 4l forming' a receiving chamber for the 4m which is arranged in approximately the longitudinal axis of the shaft ID.

The stator is surrounded by a jacket 42 providing a chamber 43 about the stator, the chamber being adapted to receive a cooling or heating agent by way of an inlet pipe 44, the agent being withdrawn through the pipe 45. 'Ihe jacket 42 may be force-fitted upon the outer surfaces of the flange 4U and extension 4I, or it may be secured to the stator member 38 in any other suitable manner.

In the form of the invention illustrated in Fig. l, the larger or discharge end of the rotor 34 is provided with a boss 38a having a plurality of radial grooves 39 running from the bore 33 to the outer surface of the rotor. Surrounding but spaced from the boss 38a is an annular flange 46 forming a horizontal extension of the stator 38. The flange 46 is spaced inwardly of the adjacent horizontal wall of the casing member 29 to provide a channel 41 which leads into an outlet 48 which opens into the channel 41 and is located radially behind the flange 46. The latter terminates a short distance from the end wall 3|.

In the operation of the mill shown in Fig. l, the iluid to be treated is charged into the chamber formed by the extension 4I, whereupon it passes into the space between the rotor and stator, where the mixture composing the fluid is subjected to the desired grinding or homogenizing action. The fluid travels toward the right, at the same time acquiring a gradually increasing velocity. As it reaches the right end of the rotor, it is thrown by centrifugal force and at high velocity against the inside surface of the flange 46. Any fluid tending to spill over the edge of the rotor and move down the right end face of the rotor toward the shaft, is flung by the walls of the grooves 38, which act as impeller 1 blades or vanes, likewise against the inside surface of the flange 46. vAlong this surface the fluid flows in a circular and somewhat spiral stream. When the uid reaches the free edge of the flange, it is still traveling at high rotary bound as it strikes the edges of the outlet opening, such rebounding fluid is prevented by the outer surface of the flange 46 from striking the shaft. The flange 46 thus provides a surface for I receiving the discharged iluid and along which the latter travels before it reaches the outlet opening, and also a surface which prevents the fluid from falling or rebounding into Contact with the shaft.

The flange 46 provides a smooth, continuous and substantially circular surface of approximately the diameter of the discharge end of the rotor. The fluid leaving the rotor thus meets with no obstruction tending to change radically its direction or speed of flow. and accordingly flows smoothly along the inside surface of the flange where its velocity is gradually reduced.

The axial length of the flange 46, or equivalent part. should be sufficiently great to cause reduction in the speed of flow of the fluid so that the fluid will not reach the outlet opening at too high a velocity: on the other hand, the flange should not be so long that the velocity of the fluid is fluid to L-c treated, such fluid being fed by a pipe reduced to the point where it is insuillcient to provided atrthis point. The absence 'of packing,

which in prior constructions had to fit very tight'- ly about` the shaft, reduces considerably the power required to operate the mill.` Whereas in prior constructions, the heat generated at thepacking was often sufficient to cause destruction thereof, in the improved `construction above described, there is practically no temperature rise due to friction at the shaft.

Should some `'leakage occur throughthe bore 32, as in thecase of a mill which is frequently started and stopped, a certain amount of fluid then finding its way to the shaft during the idle periods, such leakage can be caught in the chamber 49 from which it may be withdrawn in any suitable way.

In the form of the invention illustrated in Fig. 3, the casing member 29 is itself shaped upon its inner surface, as indicated at 46a, to provide a smooth and continuous path, free from 'obstructions, for the fluid discharging at high velocity from between the rotor and stator. The fluid travels along the more or less circular surface 46a in a spiral stream until it reaches the outlet 48. This outlet is removed fromthe discharge end of the rotor 34 a sufficient distance to enable the speed of the fluid to bereduced to such an extent that when it strikes the edges of the outlet, it is no longer able to rebound with great violence.` It is, however, desirable notv to position the outlet 48 too far from the rotor, such distance becoming greater with machines operating at higher speeds, as the length of the shaftl is then ,undesirablyincreased `To enable the discharge outlet48 to be locatedl nearer to the rotor, I provide a sleeve or bushing 5| which may be cast integral with the casing member 2S and which surroundsthe shaft in the region of the outlet 48`. Any fluid rebounding toward the shaft thus strikes the outer'surface of the bushing 5I and is prevented from working its way about the shaft i and into the sleeve 5|. In many instances, however, the sleeve is not sufficient to prevent leakage at the shaft, and in such instances, as illustrated in Fig. 3, I provide an annular' deflector 52, which is arranged in the immediate vicinity of the dischargel outlet 48 and causes return, toward the outletof any fluid which lis projected thereagainst. The deflector 52 mayin some cases be used alone without the bushing 5|, but it will generally be best to employ a deflector in combination with the sleeve. The sleeve and defiector should terminate sui'liciently in advance of the discharge outlet 48 to prevent fluid from working its way around the shaft.

The structure shown in Fig. 3 is, in principle,

.substantially the same as `that shown in Fig. 1.

the inner surface 46a in'Fig. 3 corresponds to the inner surface of the flange 46 of Fig. l; While the sleeve 5| and/or deiiector 52 of Fig; 3 correspond to the rear surface of thel flange 46 in Fig.` l.

As can vbe seen from Figs. 1 and 3,7my invention presents a considerable simplification of prior colloid mill constructions, particularly as regards the manner of preventing leakage about the shaft'. Also. by constructing the stator in the manner illustrated in the drawing, a very simple casing construction is secured, the casing and stator'struuture being made of a minimumnumber of'pa'rts, while the fluid to be treated is introduced into the machine in a convenient and eilicient manner.

The rotor and stator are` preferably provided with grooves, as shown in Figs. 3 ande. I prefer tov make the distance between the grooves, i. e. .the teeth, considerably longer than the diameter of the grooves. Thus, the grooves may be about 1,/8 inch in diameter and the teeth there-l between may be from to 1%(2 inches wide at the large end of a tapered roller which is 313 inches long, `isZF-,i inches in diameter at the large end and 121;@ inches in diameter at the small end. Iprefer to'make the number of grooves different in the rotor than in the stator; thus, with a rotor as just described, the stator may havethree grooves more than the rotor. n.

It will be obvious that `the most favorable dimentions for any particular size and -speed of machine will depend upon the capacity of the machine, the nature of` the fluid to be treated,

v the speed of the-rotor, etc., and can be determined by simple experiment. In any case, however, care should be taken that the fluid discharging from the rotor does not meet any obstructions tending to cause rebound. Y

Wear at the surfaces 'of the rotor and stator may be compensated by a suitable operation at the hand wheel 25, such operation causing longitudinal movement of the shaft Ill toward the left. Suitable clearances are provided, as between the bearing I1, I9 and the wall 50 to allow for such movement. If desired, the discharge end -oi the rotor may project slightly beyond the adjacent edge of the workingsurface of the stator, so `that when the rotor has been given its maximum adjustment for wear, the fluid dis charging from the rotor will not strike any overlyinggrooves on the stator surface.

It may be mentioned that one of the advantages of the present invention resides in the fact that by the elimination of the necessity for a special packing about the shaft, there is avoided the necessity for providing special Stellite shaft sections or other wear-resisting` surfaces. The

`shaft l0 can thus be made of ordinary material and the cost of the machine thereby reduced.

Variations from the specic design and proportions shown and described herein may be resorted to within the scope of the appended claims without departing from the spirit of the invention. Thus, in Fig. 3 a leak chamber as shown at 49 in Fig. l, maybe interposed in advance of the bearing or other means may be provided for taking care of any fluid the end wall 3|.

I claim:

l. In a colloid mill, the combination of a casing. an inlet for a fluid to be treated, a stator, a shaft journalled in said casing along the axis of the stator, a rotor fixed to the shaft to rotaie therewith within the stator, an annular flange extending from the stator approximately parallel to the shaft and closely about the discharge ond of the rotor to receive immediately the fluid discharged by the rotor, andan outlet connected to the casingat a point spaced radially from and behind said ange.

2. in a colloid mill, the combination of a casing. an inlet for a fluid to be treated, a stator, a

that may leak Apast shaft journalled in said casing along the axis of the stator. a rotor fixed to the shaft to rotate therewith within the stator, said casing having an end wall facing the discharge end of the rotor and through which the shaft passes, there .being no packing for scaling the shaft at such end wall,

les

an annular flange integral with the stator and extending approximately coaxially with the shaft and arranged to receive the fluid leaving the rotor at high velocity, said flange terminating a short distance from the end wall, and an outlet connected to the casing at a point approximately radially behind said flange, the treated fluid being thus compelled to flow axially beyond the flange before it can reach said outlet.

3. In a colloid mill, the combination of a casing, an inlet for a fluid to be treated, a stator, a shaft journalled in said casing along the axis of the stator, a rotor xed to the shaft to rotate therewith within the stator, a wall extending perpendicularly to the shaft and forming part of the casing, said Wall facing the discharge end of the rotor, the shaft passing loosely through said wall, an outlet leading from said casing, said casing being providedk with a substantially circular-surface extending approximately parallel l to the shaft and arranged to receive the fluid discharged by the rotor and arranged between the discharge end of the rotor an-d the outlet, and

with a surface lying between the discharge opening and shaft and acting to protect the shaft against impingement -by fluid rebounding from the edges of the opening. A

4. In a colloid mill of' the horizontal type, the

' Vcombination of a casing, a stator fixed tothe casing, a horizontal shaft journalled in said casing along the axis of the stator, a rotor fixed to the shaft to rotate therewith within the stator, means at the discharge end of the rotor for projecting fluid flowing from between the rotor and statoroutwardly towardthe casing and away from the rotorsupporting shaft, said casing including an end wall facing the discharge end of the rotor and having an axial opening through which the shaft loosely passes, there being no packing about said opening, an annular flange approximately coaxial with the shaft and fixed to a stationary part at the discharge end of the rotor and radially spaced from the adjacent casing wall to receive the fluid leaving the rotor, at

high velocity, said flange terminating axially a short distance from the end wall, an outlet through the casing at a point behind said flange, and a collecting chamber upon the side of the end wall opposite the rotor for receiving any fluid that may leak through said opening.

5. In a'colloid mill, the combination of a casing, an inlet for a fluid to be treated, a stator in the casing, a shaft journalled in said casing along the axis of the stator, a rotor fixed to the shaft to rotate therewith within the stator, means providing a substantially circular path, free from obstructions and extending substantially parallel to the shaft, immediately at the discharge end of the rotor for receiving directly the treated material as it discharges from between the rotor and stator, and an outlet arranged to receive the treated fluid after the latter has traversed said circular path, and so removed from the shaft that the fluid reaching it is unable to rebound and impinge thev shaft, said means being located between the discharge end of the rotor and said outlet,

6. In a colloid mill of the horizontal type, the combination of a casing, a stator, a horizontal shaft journalled for rotation within the stator, a rotor xed to the shaft to rotate therewith within the stator, said casing including an end wall facing the discharge end of the rotor and having an axial opening through which the shaft loosely passes, there being no stuffing box about through the casing at a point behind said flange,

said flange being radially spaced from said outlet to provide a, collecting space between itself and said outlet.

7. A colloid mill as set forth in claim 6, where-y in the vertical end face of the rotor at the discharge end thereof is provided with impeller surfaces acting to throw against the inner surface of the flange any fluid spilling over the edge of the rotor.

8. A colloid mill as set forth in claim 6 wherein the discharge end face of the rotor is provided With a boss having radially extending grooves therein, the said grooves acting to collect fluid spilling over the discharge edge of the rotor and direct the same toward .the flange.

9. In a colloid mill of the horizontal type, the combination of a casing, a stator, a horizontal shaft journalled for rotation along the axis of the stator, a rotor fixed to the shaft to rotate therewith Withinthe stator, said casing including an end Wall facing the discharge end of the rotor and arranged in proximity thereto, said end wall having an axial opening through which the shaft loosely passes, there being no packing about said opening, an annular flange approximately coaxial with the shaft and xed to the'stator at the discharge'end of the rotor and forming an extension of the stator, said flange being radially spaced from the adjacent casing wall and extendingto the Vicinity of the casing end wall, said flange overlying the region of discharge of the fluid from between the rotor and stator and receiving there being a relatively narrow passageway between the free edge of the flange and the casing end wall and between the outer surface of the flange and the surrounding casing wall, and an outlet through the latter casing wall at a point behind said flange.

l0. A colloi-d mill as set forth in claim 9, wherein the discharge end face of the rotor is provided with grooves acting to direct against the inside surface of the flange any fluid spilling over the edge of the rotor.

ll. In a colloid mill of the horizontal type, the combination of a casing, a stator, a horizontal shaft journalled for rotation along the axis of the stator,v a rotor xed to the shaft to rotate therewith within the stator, said casing including an end wall facing the discharge end of the rotor and arranged in proximity thereto, said end wall having an axial opening through which the shaft passes, an annular flange approximately coaxial with the shaft and fixed to the stator at the discharge end of the rotor, said flange being radially spaced from the adjacent casing wall and vextending to the vicinity of the casing end wall, said flange overlying the region of discharge ofA rotor for receiving directly the treated material as it discharges from between the rotor and stator, and an outlet arranged to receive the treated fluid after the latter has traversed said l circular path, said means being arranged between the outlet and the discharge end of the rotor to shield the outlet against direct entry of fluid from between the rotor and stator.

13; In a colloid mill, the combination of a caslng, an inlet for a. fluid to be treated, a stator, `a. shaft journalled in said casing along the axis `of the stator, a rotor fixed to the shaft to rotate therewith within the stator, an outlet leading from the casing, and a fixed annular member surrounding the yshaft and spaced radially inwardly from the outlet, said member lying between said outlet and the discharge edge of the rotor and ybarring direct entry into said outlet of fluid`-dischargingfrom the rotor.

14.- In a colloid mill of the horizontal type, the combination of a casing, a stator, a horizontal shaft journalled for rotation within the stator, a rotor fixed to the shaft to rotate therewith within the stator, said casing including an end wall facing the discharge end of the rotor and having an axial opening through which the shaft loosely passes, there being no stuffing box about said opening, a flange extending approximately coaxially with the shaft and fixed to the stator and immediately overlying the adjacent region of discharge of the fluid being treated from between the rotor and stator, said flange terminating axially a short distance from the end wall, and an outlet through the casing at a point behind said flange, said flange being annular in form and being throughout spaced in a radial direction from the adjacent wall of the casing and from the outlet to provide a collecting space between itself and said outlet.

l5. In a colloid mill of the horizontal type, the combination of a casing, a stator, a horizontal shaft journalled for rotation within the stator, a rotor fixed to the shaft to rotate therewith within the stator, said casing including an end wall facing the discharge end of the rotor and having an axial opening through which the shaft loosely passes, there being no stullng box about said opening, a flange extending approximately coaxially with the shaft and fixed to the stator and immediately overlying the adjacent region of discharge of the fluid being treated from between the rotor and stator, said flange terminating axially a short distance from the end Wall, an outlet through the casing at a point behind said flange, said flange being radially spaced from said outlet to provide a collecting space between itself and said outlet, and a collecting chamber upon the side of the casing end wall removed from the rotor to receive any fluid that may pass through the opening in such end wall.

LOUIS GITZENDANNER.

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