US2463886A - Mixing apparatus - Google Patents

Description

March 8, 1949.

Filed Sept. 29, 1945 G..` J. I ANGMYHR 2,463,886

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G. .1. LANGMYHR MIXING APPARATUS 3 Sheets-Sheet 2 Filed Sept. 29, 1945 I INVENTR Georsz John Lanmqhr 'AT1-anniv March 8, 1949. G. J. LANGMYHR 2,463,886

MIXING APPARATUS Filed Sept. 29, 1945 3 SheebS-Sheeb 3 lNvaN-ron Langmxihr l Patented Mar. 8, 1949 UNITED STATES PATENT OFFICE.

MIXING APPARATUS George John Langmyhr, Sarnia, Ontario, Canada Application September 29, 1945, Serial No. 619,338

This invention relates to the art of mixing fluids and the like in tanks or Vessels.

In the chemical and related industries, it is necessary to mix fluids of various viscosities and densities, some of which are so heavy that a considerable amount of power is consumed during operations. A further problem arises when chemical compounds which are to react with each other and produce a new chemical result are being mixed complete inter-mingling of the component is required, otherwise the speed of the reaction is slow and the process inefcient.

The common type of mixer which consists of a paddle or propeller rotating on the end of a drive shaft has proven ineffective for modern use. Of the many disadvantages of this type of mixer the most serious is that it often rotates the liquid around the containing vessel without proper intermingling of the various ingredients or components. This lack of inter-mixing is called stratification and proves to be a serious problem particularly where chemical reactions vare part of the process.

An additional disadvantage of the common type mixer is that the propeller is usually operated at a much faster speed than is theoretically necessary in order to achieve the desired results. Because of the violence of the propeller, loses due to spillage are high and there is also the danger of rothing of the liquid due to the excessive amount of air which may be beaten into the liquid.

The ordinary paddle type mixer suiiers from the further disadvantage of consuming an excessive amount of power, frequent breakage of blades and the fact that it cannot be conveniently used in tanks under pressure or vacuum.

One of the objects of the present invention is to provide a mixing machine which will efficiently cause inter-mingling or contracting of the various components in a liquid mixture.

A further object of this invention is to provide a machine which will be capable of being used in pressure vessels and being removable therefrom without emptying or shutting down the tank.

This invention provides an apparatus to overcome the disadvantages mentioned above. The machine of this invention eliminates to a large degree the danger of incomplete inter-mixing by providing a zone of turbulence which takes the form of a solid of revolution. The liquid or solid particles in this turbulent zone are continuously inter-mingled and fresh surfaces exposed in order that chemical reaction may take place.

Thisv zone of turbulence which is usually spher- 8 Claims. (Cl. 259-99) ical in shape is created by the novel apparatus invented. The apparatus consists of a revolving tube immersed in the liquid to be mixed and of sufficient diameter to carry within it a shaft connected at its liquid extremity to a plurality of rotating impellers. The combined rotation of the tube and the impellers creates the spherical solid of revolution.

Ports or openings in the walls of the revolving tube provide additional mixing. Liquid entering these ports is stirred by one or more downwardly thrusting propellers mounted on the shaft within the tube. These ports and propellers are mounted so that they are clear of the arcs of the revolving impellers. Liquids to be mixed are thoroughly inter-mingled either upon entering the turbulent zone directly or by the propellers in the tube prior to being forced into the turbulent zone.

The accompanying drawing describes the invention in detail and will assist in the proper understanding of the operation and functioning of the device.

Figue l is a vertical section of the preferred form of apparatus.

Figure 2 is a part sectional view of a portion of the mixer showing the impellers in their operative position.

Figure?, is an elevation of the structure showing an arrangement whereby the mixer may be withdrawn from vessels operating under pressure.

Figure 4 is an alternative drive for counter shaft impellers.

Figure 5 is a plan view taken at A--A of Figure 1.

Figure 6 is a plan view of the turbulent zone.

Referring to Figure 1, the tank or vessel holding the liquid or the like is shown at I. Mounted on I is a tubular base seating 3 of any suitable shape, but preferably cast or formed in one piece. A packing or sealing ring 2, provides a iluid tight sealing means between tank and member 3. Located within the base seating ring is a revolving tube or housing 5 extending into the liquid to be mixed. The tube 5 is rotatable within the bore of the mounting 3 and eiective fluid sealing means is provided by the gland 'l and the stuiling box 8. The revolving tube 5 has a thrust ring 9 securely attached thereto and bears upon the ring I0 in the base seating 3 and sealing ring II forming the bottom of the stufng box 8.

- A flange I2 is mounted at the outside end of the revolving tube 5. A plate I3 secured to the ange I2 by studs I4 closes the outside end of the tube 5.

A bracket I5, preferable cast integrally with the base seating 3 supports a motor mounting bracket I6, the two being fastened together by bolts l1. An extension arm I8 of the bracket I6 carries a suitable bearing I9 for the pinion shaft 20 which connects the pinion 2I and the motor 22 by means of the coupling 23. The extension arm I8 terminates in a boss 24 and carries the main shaft 25 with thrust bearings shown at 26.

Eeotive power transmission'means to rotate the tube '5 and shaft 25 is provided by bevel gear 2l attached to shaft 25 and bevel gear 28 secured to plate I 4 by studs 29. Packing means are shown at 30 to effectively seal the exit of shaft 25from plate I3. The transmission just described has been found to be quite eilicient but any other transmission may be substituted without altering the invention.

The main shaft 25 has a pinion 3| mounted on the lower end thereof and a main bearing 32 suitably mounted. The pinion 3l is in operative contact with bevel gear 33 which is secured Ato counter shaft 34. Suitable bearings 35 attached to the tube support the counter shaft. Mounted on the counter shaft are a plurality of collars 36 from which extend outwardly a plurality of impellers 37. The impellers 3l which may be of any shape or size rotate in an arc parallel to the main axis of thetube 5. In order that any reasonable sized impeller may be used slots 38 are cut in the tube 5 which permits the radius of the arc to be greater than the radius of the tube.

Figure 4 illustrates an alternate form of power transmission means for the impellers wherein Spiral 01 worm gears 39 and 40 replace the previously described pinion 3| and bevel gear 33. The inherent self-cleaning feature of this design may be desirable for use with certain liquids.

With liquids whichcarry a high percentageof abrasive'solids, it might be necessary and advisable in order to prevent undue Wear of the impeller drive means to completely inclose the latter in a protective housing. This feature has notbeen shown in the drawings.

Ports or opening 4I, located in the walls of tube 5, permit liquid to be drawn into the interior of tube 5. These ports are always located above or clear of the arc of the impellers 31. Liquid. which has entered through the ports 4I vis stirred and thrust downwardly by a plurality of propellers 42 securely mounted on shaft 25. The propellers 42 must be located in such a manner that they clear the arc of the rotating impellers.

It has been found that scoop-like projections 43 as shown in Figure 5 materially increase the now of liquid through the ports 4I. Theprojections should face in the direction of Vrotation of the tube 5.

In operation the tube 5 is immersed into the liquid or the like to a depth which may vary with the type of liquid being treated. Thetube isrotated by lmeans of the transmission meansdescribed above. Simultaneously .the impellers 3l are rotated. The combined movement of the tube and impellers creates a solid of revolution in the liquid being vstirred as shown in Figure 6. This solid of revolution is spherical. in shape and creates a zone of turbulence in which intimate mixingoccurs. Liquid is drawn into the tubes through the ports 4I and is stirred in a downwards direction by the propellers 42. The apparatus may be mounted on an open tank or a closed tank and may be mounted vertically or` at any anglefdown to the horizontal. I

The apparatus is capable of operation without the rotating impellers as eilcient mixing Will occur with the revolving tube and the propellers 42 The speed of operation of the apparatus will, of necessity, require adjustment for the particular type of liquid being treated. Varying density and percentage of solids to liquids prevent any range of rotative speeds being disclosed. The speed .at Iwhich the various components rotate may easily be adjustedby changing :the various driving gears.

In Figure 3 an alternative form of the invention is disclosed which is capable of use with tanks operating under positive or negative pressures. In this modification the base seating member 3 is made longer in order that the revolving tube 5 along *withr the rotating impellers may be drawn up into the interior of member 3. A valve 44 is provided to seal the tank as soon as the apparatus is clear of the valve. A sealing member 45 of greater height is provided in place ofthe member 2 to provide lheadroom for the handle of valve 44. When using this modification the impeller blades must be attached in such' a manner that when stopped the blades will be within the conlines of tube 5. It is obvious that the projections shown in Figure 5 could not be used with this modification.

The shape of the impeller and propeller blades shown `has proven quite efficient in operation but itis understood that the invention is not restricted in any way to the particular shape described.

'It is understood that the apparatus may be con structed from any suitable metals or non-metallics Without departing from thescope ofv this invention.

Throughout this Vspecification andthe claims the term liquid has been used broadly with reference to the material being mixed. It is-understood `that the term liquid will encompass liquids of 'all usual densities and mixtures of solids and liquids.

I claim:

l.. A mixing device for liquids and the like comprising a vertically mounted revolving tube immersed into the liquid to be mixed, a vertical shaft located lin said tube and rotating in a vertical plane impellers mounted at the base of said tube, said impellers rotating through longitudinalslots in the 'wall of said revolving tube, horizontally rotating downwardly thrusting propellers mounted on said shaft above the arc of said rotating im` pellers, av plurality of ports in the walls of said tube through which fluid is drawn into said tube above the arc of said impellers, common means to rotate said tube `and impellers.

2. In the device disclosed fin claim 1 means mounted on the external circumference of said revolving tube to urge the fluidthrough said ports.

3. `In a mixing device for liquids andthe like, arevoIving tube immersed in said liquidsmeans to support said tube, means to prevent liquid from escaping between said supporting means and said tube, a shaft located in said tube and operatively connected to impellers rotating in av vertical plane mounted at the bottom vof said tube, said impellers,;rotating through longitudinal slots cut in the revolving tube, one or more downwardly thrusting propellers mounted on said shaft above the arc Aof the rotating impellers, a pluralityof ports in the walls of said tube, means externally mounted over Ysaid ports lIto-:urge iuidto enter,

the combined movement of said tube and impellers tracing a spherical solid of revolution.

4. A mixing device for liquids and the like capable of being mounted on a tank or vessel comprising a revolving tube immersed in said liquids, means to support said tube, means to prevent liquid from escaping between said supporting means and said tube, a shaft located in said tube and operatively connected to impellers rotating in a vertical plane mounted at the bottom of said tube, said impellers rotating through longitudinal slots in the revolving tube, one or more downwardly thrusting propeliers mounted on said shaft above the arc of the rotating impellers a plurality oi' ports in the walls of said tube, means externally mounted over said ports to urge iiuid to enter, the combined movement of said tube and impellers tracing a spherical solid of revolution.

5. In the device disclosed in claim 4 wherein the external means to urge the liquid to ow into the tube consist of scooplike projections, the mouth of said projections facing the direction of rotation of the revolving tube.

6. In the device disclosed by claim 4 means mounted in said supporting means to permit the l device to be removed from a tank operating under positive or negative pressure without affecting said pressure.

7. In a mixing device for liquids and the like capable of being mounted on a tank, a revolving tube or housing extending into the liquid to be mixed, supporting means for said tube, means to prevent leakage of liquid between said tube and said supporting means, a shaft extending through said tube and operatively connected to and rotating impellers mounted at the liquid face of said tube, said impellers rotating in a plane parallel to the major axis of said tube, said impellers rotating through longitudinal slots in the Walls of said tube, common means to rotate said tube and impellers.

8. In a mixing device for liquids and the like capable of being mounted on a tank, a revolving tube or housing extending into the liquid to be mixed, supporting means for said tube, means to prevent leakage of liquid between said tube and said supporting means, a shaft extending through the centre of said tube, and operatively connected to and rotating impellers mounted at the liquid face of said tube, said impellers rotating in a plane parallel to the major axis of said tube, said impellers rotating through longitudinal slots in the walls of the said tube downwardly thrusting propellers mounted on said shaft and ports in the walls of said tube.

GEORGE J LANGMYHR.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 490,498 Pnetz Jan. 24, 1893 913,986 Sharp Mar. 2, 1909 FOREIGN PATENTS Number Country Date 237,341 Germany Aug. 5, 1911

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