US2516917A - Agitator - Google Patents

Description

All@ l, 1950 A. J. RouBAL 2,516,917

AGITATOR Filed. Dec. 14, 1945 lll//I/I//IA Patented Aug. 1, 950

UNITED .STATES PATENT O FFlCE asiaei i miraron y Alexander J. Roubal, .Milwaukea Wis., assignor to Allis-Chalmers Manufacturing, Company, Mil- Waukee, Wis., a corporation of Delaware Application December 14, 1945, serial No. 634,931

`r Claim. (o1. 25e-+108) This invention relates to improvei'nents in agitators `for nuid mixtures of the type in which a `substantially vertical agitator shaft carrying to various oonsistencies of uid mixtures to be treated, and improved `means for mounting the impeller in the tank.

An object of the inventionis to vprovide an impeller in which a fluid propeller or agitating means is attached to a rotating shaft by means providing for readily securing thepropeller in any one of a plurality of positions of adjustment axially of the shaft, l

` A further objectof the invention is to provide cooperating axial and radial impellers for causing duid to be e'iciently propelled downwardly along the shaft and outwardly across the tank bottom.

A still further object is to provide animpeller with an improved submerged `bearing for location of the lower `end of the shaft in the tank, in which the bearing is properly protected-from entrance of `liquids by the diving bell principle,

and provision is made for lifting and lowering of The above mentioned and still` further objects and advantages may be secured and carried into practical effect as described below with reference to the accompanying drawing in which:`

Fig. 1 is a vertical sectional View of "an agitator according to the present invention;`

Fig. `2 is an enlarged vertical sectional "view of the submerged shaft end and bearing structureshown in Figi;

Fig. 3 is a cross sectional view taken on the Fig. 4 is a top elevation of thebeari'ng receiving base shown` inFig. 2 with bearing' structure removed.

In a preferred embodiment of the invention illustrated in the drawing, a tank I for containin a tank such impeller being readily adaptable 110 l I.` ing a `body of fluid mixture to be agitated,` has `a `frame 2 extending `across the top, on which is mounted an agitator drive mechanism 3 afer supporting and rotating an impellershaft 4 extending vertically `downward into and substantially to the bottom of `tank I. The shaftsupporting assembly 2-3 and shaft i4 is arranged `so as to be removable upwardly from .and `replaceable downwardly to the operative position illustrated,

Secured to shaft 4 intermediate its length,.and within the tank when the shaft 4 is in operative position, is a fluid impeller, which in the present `embodiment is a propeller 6. Propeller 6 is arranged to propel fluid mixture generally down- /wardly in the vicinity thereof, along shaft 4, when the shaft is rotated in operating direction on its `axis. l l l vAs shown, and according to the presentinvention, the propeller li is keyed in axially slidable driven relation to shaft 4, A conventionalkeyway is shown at 1 for reception of a conventional key (not shown) suitably engaging the hub 8 of propeller E in known, suitable, manner to prevent relative rotationof the propeller andshaft in operation. Propeller locating spacer sleeves 5` are. provided to fit slidably on the `propeller mounting portion of the shaft 4. A shoulderII forms an abutment limiting the axial. movement .in onedirection of the sleeves 9, and hub 8, which are arranged in selected order on the shaftf in series abutting relation to shoulder II. It will be clear that if the hub 8 abuts I I with all sleeves 9 between it and the lower shaft end, the propeller 6 will occupy. an uppermost position shown by broken lines in Fig. l; and if all spacer sleeves `9 `are placed above the hub 8 the propeller E` will Loccupy a lowermost `position shown by broken `lines in Fig. l, as compared with the position of the` propeller ;6 als indicated` in full lines :in Fig. l. The sleeves B and hub 8, assembled in selected order on the shaft 4, are clamped in position between shoulder I i and clamp plate I 2 as shown in Fig, l. Plate I2 is secured, as by cap screws t3, to the lowermost end of shaft 4, and projects :beyond the shaft periphery sufliciently to engage the sleeves; ll or hub 8 in clamping relation, either directly (not shot-vnl1 or indirectly `through an additionalyend spacer, which, inthe drawing, is

ShW e3 e afiged Coupling member I4 adapted for attachment of a bearing housing member f6,

l described hereinbelow.

erally acting forces, a bearing surface, such as cylindrical stub shaft I8, is provided within the housing I6. Housing I6 is arranged to form a fluid tight bell housing adapted to retain a gase- -ous fluid atmosphere under pressure, which will prevent access of a liquid `mixture in tank I to the bearing surface of I8 so long as the housing I6 is fluid tight down to a level substantially bellow any part of the `bearing surface of I8.

' In' radial bearing engagement'with the bearing 'surface of vE8 isa relatively rotatable bearing member or bushing' i9 which may be provided,

as shown, with a` self lubricating liner 2I formingv an actual bearing surface. Bearing member `I9 is preferably closed 'at the bottom to make it fcup shaped, but need not be so closed provided it has no opening extending below the fluid tight portion ofthe bell housing I8. As shown, bushing I9 is formed with a frusto-conical external surface 22 which forms a pilot bearing, or lateral thrust transmitting and centering surface adapted to engage a complementary surface 23 von a pilot bearing base 24, in the tank bottom. Further, the bushing I9 may have a lateral exltension lor 'extensions 25 cooperating with a re- "taining ring or lifter plate 21, which is secured to the housing I6 after assembly of bushing I9 on stub shaft I8,"to limit axially outward motion of bushing I9 relative to 'housing I6.

Pilot bearing base 24 may be formed as shown, :as an annulus 28 supported by an open cage 29 secured to the tank bottom in any suitable manthe relatively rotating interengaging bearing siii*i faces of elements I8 and 2 I.

Occasionally, for example as a result of stoppage of the impeller, solids may collect in the vicinity of the opening of bell I6 and around the blades II which would, if not removed, tend to impede rotation f the impeller and tend to intrude into thehoiising Ilia,4 To prevent this, and to effectively ma'intainthe atmosphere in bell ls. excess air may be intermittently or continuously forced through pipe 3l and nozzle 32. Excess air so supplied will escape around the mouth of the bell I6 and force any settling solids away from the vicinity .of the housing, bearing and impeller vus ner. However, any suitable device for freely ref-ceiving bushing I9 in lateral thrust transmitting *pressure within the bell housing I6, and for ad- -lnis'sion ofexcess air, a pipe 3l is provided with nozzle tip outlet 32 vertically below the opening lof bell housing It when in operative position. Pipe 3l' is connected with a suitable source of gaseous fluid under pressure (not shown).

fin operation of lthe agitator described above, a fluid-mixture, 'such as a liquid with'ine solids l'suspended therein, is placed in the tank I. Rotation of shaft 4 causes propeller 6, properly set -tc best level for the particular material being treated,y to propelv liquidsor liquid suspensions fdownward along shaft 4. Impeller blades I'I -fcause liquid surrounding housing It to be impelled radially outward over the bottom of tank wl. These actions cooperate to create an optimum agitation of fluids in the tank. Supply of :air through pipe 3| and nozzle 32 maintains a 4`gaseous atmosphere under pressure in housing I6 which, by the diving' bell principle, prevents the 'entrance of any liquid into bell I5 above a level determined by the fluid pressure within bell I6. The liquid level in bell housing I6 vis maintained sufficiently low to prevent intrusion of liquid into structure, thus increasing the effectiveness of the device in maintaining or obtaining a homogeneous mixture in the tank.

When it is necessary to lift shaft 4 with its impellers, for any reason such as repairs, it will be seen that lifter plate 2l will engage projections 25 and, lift bushing I9 with the housing I5. This providesfor lifting; ofthe ywhole operative bearing structure'with the shaft` -Reinsertion of the agitating mechanism in 'a full tank will be facilitated by provision of the selicentering pilot surfaces 22 and 23. .Since surface 23 is supported by a cage, no fiuid can be trapped when surface 22 isv engaging surface 23. Accordingly, the shaft d may bezfreely lifted and lowered from and to operative position without danger of fouling of the bearing by the liquid mixture in the tank.

While fa specic embodiment of the invention has been illustrated and described, it will be understood that the invention is intended to include such modifications and equivalents as may be within the scope ofthe appended claim.

It is claimed and desired to secure by Letters Patents" i- '1 In an agitator having a substantially vertical rotating shaft, a bearing member engaging said shaft in relatively rotatable relation,.said shaft being located at its *footl by engagement' of said bearingmember with a surface below the level of a body of liquid, a downwardly open bell hous- 4 ing carried at the foot of'said shaft and surrounding said relativelyrotatable member, in upwardlyuid-v tight relation, agitator blades extending radially from the external surface of said .bell housing for operative rotation with said shaft, and meansfor supplying a gaseous fluid .under pressure `to said bellhousing for maintain'- ing a gaseous atmosphere within said bell and blowing particles of settled solid matter away from the vicinity-of said bell housing and blades.

, l. ALEXANDER J. ROUBAL.

REFEREN CES- CITED The following references are o f record in the file of this patent:

I Flanders Mar. 6, 1945

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