US 2615697 A
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Description (OCR text may contain errors)
Oct. 28, 1952 K. s. VALENTINE 2,515,697
DISPERSION APPARATi IS Filed Dec. 10, 1949 2 SHEETSSHEET 1 FIG. I FIG. 3
ATTORNEYS Oct. 28, 1952 K. s. VALENTINE ,6
DISPERSION APPARATUS Filed Dec. 10, 1949 2 SHEETS-SHEET 2 INVENT lawn/A Jzer/zz'gy 4.20/12 ATTORNEYS lower opening of the impeller.
Patented Oct. 28, 1952 UNITED sures PATENT oFFIcE 4 7 12 515597 DISPERSION APPARATUS Kenneth- Sterling Wa'lentine, New York, N. Y., as-
signor to The Patterson Foundry f& Machine 'Co.,-'New YorlgfN. Y., a corporation of Ohio Application December 10, 1949, Serial No. 132,231
' 6 Claims. (Cl. 261-93) I 'Thisinvention relates .to apparatus forthe dispersion of gas in liquids and hasfor its object the provision of an improved apparatus for this purpose. My invention provides apparatus including at least one impeller-stator unit or combination operatively mounted within a'confining vessel for the gas and'liquid which efiects an efficient mixture of gas and liquid resultingin improvements in dispersion. The unit of myinvention comprises an e'fiicient impeller disposed to discharge the liquid and gas radiallyinto a surrounding stator having a downwardly curved peripheral portion and stationary "blades which shear the liquid and gas, causing great turbulence and intermixing.
The invention comprises a container for "the liquid and gas having mounted thereiniat least one,.and preferably several, impeller-stator units each comprising, an impeller rotatably mounted on an'upright shaft, and a surrounding stator. Theimpeller-stator combination is characterized by spaced plates mounted on the impeller and stator in mating relation and providing contiguous lateral spaces. The impeller plates are more or less horizontally disposed and'the plates'ofthe stator are preferably curved downwardly at its periphery and the liquid and gas are forced to flow outwardly and downwardly. The plates of the impeller have centrally-disposed openings for the entrance from below and above of the liquid and gas mixture which is sucked intothe central part of the impeller and forced to flow through the lateral spaces. Theinvention comprises any suitable means to vary the sizes of'the openings. To this end I may provide a hub for the impeller on which are mounted interior segmental plates at the openings with means for adjustment. to vary the sizes of the openings and the rate of'flow of liquid. I may provide any other suitable means to vary the openings in the plates, such as the, diaphragm opening of a camera, or rings of suitable width disposed over the openings. The openings may be adjusted individually or jointly and from a means at the exterior of the container, if desired.
I prefer. to employ an impeller having blades which are slightly curved and covered from the periphery to the central opening which is smooth to effect a non-turbulent whirlin of the liquid at the intake. The whirling intake creates a good flow of liquid without turbulence and therefore induces a smooth high rate of flow of gas into the top of the impeller. The curved impeller blades induce a smooth flow of the mixture into the The impeller blades maybe set-at a small angle, say, '5 to 6,-
to deflect the liquiddownw'ardly'. By regulating the areas of the upper and lower intake "openings inthe impeller, the zones of liquid and gas-located above and below the impeller level-may be given any desired degree of mobility or quiescence. Also, the f top and bottom intake quantities may beba lan'ced. v a
'In order to effectabettercontrolover theflow of liquid through the contiguous spaces of-the impeller-stator, I prefer'to provide a lip'over' the areabetween theimpeller andstator'pIates, preferably attached to the stator, and I' may attach a lip to-either theupper plate or thelower plate, or to both. The shrouds prevent an-upper-escape of gas "and cause all-material'dischargedfrom the impeller to ;be directed through the space *between the stator plates, thus providing amaximum of shear. a
In another embodiment of the-invention, 1 provide one or more partitions between-the plates of the impeller and stator to'f'orm ppera'na lower sections therein. I may extend the partition to, or approximately to, the hub to serveas a 'baflle to preventpundue 'intermingling' were impeller streams entering'irom above and below.
The partition may be providedwit'hmeansior vertica'ladjustment upward'or downward tov-ary the relative amounts of gas-liquidmixture *circulated and a central opening mayy'be provided in the partition whichmay be adjustable to vary the rate of exchange of now between the upper andlower parts of the impeller. Itis very'ojften desirable to use adouble impeller-stator. unitinstead of two single ones;ffor instance, incontainers where the height is much less "thanthe diameter and there is no roomior'two impellere stator units.
While the apparatus of the invention is Lintended for general application in't'he dispersion of a gas in a'liquid, it is especially eflicaciousyfor use in operations in which thegas is absorbed by, or reacts with, the liquid asinthe hydrogenation of fats andoils, or with a .solid suspended in the liquid.
' The apparatus. of the invention effects la depressing and re-depressing of the gas, overcoming its natural tendency to rise and to separate partially from theliquid, .by. causing .all or the major portion of the mixturelincluding .theiinely dispersed gas to circulate rapidly -and.repeatedly in an outward and downward direction and thence in an inwardand upward .directionin a .broad sweep,thus following .an extended pathpf travel.
These and other-objects of the invention will be better understood after considering the following discussion taken in conjunction with the accompanying drawings, in which:
Fig. 1 is a sectional elevation of a gas dispersion apparatus embodying the invention;
Fig. 2 is an enlarged plan view at 22 of Fig. 1;
Fig. 3 is an enlarged sectional view taken at 33 of Fig. 2;
Fig. 4 is a plan view, with the upper plate removed, of a modified form of impeller blades;
Fig. 5 is a vertical sectional view of a modified form of impeller-stator unit of the invention;
Fig. 6 is a plan view of the unit of Fig. 5;
Fig. 7 is a vertical sectional view of another embodiment of impeller-stator unit of the invention, and
Fig. 8 is a plan view of the impeller-stator unit of Fig. 7.
The apparatus illustrated in Figs. 1, 2, and 3 comprises a container I closed at the top with a removable cover 2 in which are ports 3 and 4 for the supply of liquid and the removal of gas respectively. The port 5 at the bottom is for the removal of treated liquid and the port 6 with its connected manifold I are for introducing a gas into a liquid.
The motor 8 and speed-reduction gear unit 9 are mounted by the frame structure III on the top of the cover. The drive shaft I2 passes through the stuffing box I3 in the cover and is held in a fixed position at the bottom by the bearing I4. At spaced intervals along the shaft the impellers I are mounted to rotate therewith. The supporting rods I5 and I6 are attached to the cover with the lower ends secured in openings in the blocks I1 and I8. The stators S are attached to the rods and the horizontally disposed rods I 9 extend from the wall of the container and are attached to the rods I5 and I6 which they support in proper alignment. The entire assembly of elements attached to and supported by the cover are removable upwardly from the container on removal of the cover.
Figs. 2 and 3 illustrate an impeller-stator unit such as is used in Fig. 1. The impeller comprises a hub keyed to the shaft I2 with radially disposed and preferably curved impeller vanes V to which the flat interior annular cover plate sections or rings 3I and 32 are attached. The exterior annular upper and lower cover plate sections 33 and 34 are also attached to the vanes.
The short peripheral intermediate vanes V are merely attached to the plates 33 and 34. The rings 3| and 32 have centrally located inlet holes or openings 35 and 36 respectively for the entrance of liquid and gas from above and below. The size of the openings 35 and 36 may be changed by substituting the rings for rings having different sizes of openings.
The stators comprise a plurality of radially and vertically disposed blades B which are secured inside the upper and lower cover plates 31 and 38. The rods I5 and I6 are attached to these cover plates and hold the stators in position. The downwardly curved shape of the stator is a continuation of the downwardly curved peripheral portion of the impeller, the respective cover plates being in mated relation with a small clearance space 39 therebetween. In order to prevent an undue passage of gas through the space 39 the upper and lower lips 4| and 42 are attached to the plates 31 and 38 respectively.
The uppermost stator is preferably located in the container so as to provide for an appreciable depth of liquid thereabove and a relatively greater depth of gas. The lowermost impeller-stator 4 unit is located a sufiicient distance above the bottom of the container to permit relative quiescence where the treated liquid leaves through port 5.
In the modified form of impeller shown in Fig. 4, the vanes V and V are inclined from the vertical a slight amount, for example, from 5 to 6, to aid in directing the downward movement of the mixture.
In the modification of impeller-stator unit illustrated in Figs. 5 and 6, the upper and lower cover plates 45 and 46 for the impeller and the upper and lower cover plates 41 and 48 for the stator are similar to those illustrated in Figs. 1 to 3. In this modification, however, a partition 49 is mounted in the impeller and extends from the hub to the periphery. I may, however, provide an annular opening at the hub for the flow of some liquid and gas between the two lateral spaces 50 and 5| in the impeller. The partition 52 is mounted in the stator and is shaped and located to effect a continuation of the curved shape of the peripheral portion of the partition 49. Partitions 49 and 52 may be spaced at different positions with respect to cover plates 45 and 46 and 41 and 48 respectively. The exterior covers and partition are preferably in substantial parallelism. The removable rings 53 and 54 provide a means for adjusting the sizes of the openings 55 and 56 respectively. The space between the impeller and stator may be covered at either the top or bottom, or both, with lips 51 as in Fig. 2. A double impeller-stator unit of the type illustrated in Figs. 5 and 6 is particularly useful in relatively short containers in which but a single stage is used. For example, in a container having a height about one-third the height of container I, one double impeller-stator unit may be used very effectively.
Figs. 7 and 8 illustrate a modification of the impeller of Figs. 1 to 3 in which the central openings of upper and lower cover plates 60 and GI are each individually adjustable by closure means movable upward and downward to vary the flow of gas-liquid mixture into the impeller from above and below. As best shown in Fig. 8, the closure means are in the form of segments 62 and 63 shaped and proportioned to be moved upward and downward in the quadrants between the vanes V. The inner edge portions of the segments are attached to sleeves 64 and 65 which are in turn attached to rings 66 and 61 in close slidable contact with the shaft I2. These rings may be slid to any desired position and secured to the shaft by pins 68 and 69 inserted in holes at spaced intervals on the shaft. It will be apparent from the foregoing discussion that the segments may be moved away from each other to provide the minimum openings at the top and bottom of the impeller and may be moved towards each other to Drovide the maximum openings.
In the operation of the apparatus of the invention illustrated in Fig. 1, liquid or a liquidsolid mixture enters the container through port 3 and the treated liquid leaves through port 5. The liquid is maintained at a level above the upper impeller-stator unit. Gas enters through port 6 and manifold I and the gas which has not combined with, or been absorbed by, the liquid passes out through port 4. In each unit the mixture of liquid and gas enters the impeller from both the top and bottom and is discharged outwardly and downwardly. Some of the liquid from each unit flows upwardly and both streams flow in a loop back to the center of the impeller creating a moving body of fluid somewhat in the shape of a doughnut. The uppermost impeller draws the liquid into the center creating a vortex which draws gas from the space above the liquid and intermixes it with the liquid. As the general mass of the liquid moves downwardly and the gas moves upwardly in countercurrent relation, the liquid and gas are subjected to several stages of very violent and effective intermixing which is repeated many times depending on the retention time in the container. The invention may also be used for batch operations.
1. Apparatus for the dispersion of a gas in a liquid which comprises a container, means for introducing gas into the lower portion of the container and a liquid into the upper portion of the container, at least one combination stator and impeller unit in the container, upper and lower plates on the impeller with the impeller blades between, a shaft for the impeller, segmental plates adjustable upward and downward on the shaft between the impeller blades to vary the size of upper and lower openings for the impeller at its center for the entrance of liquid and gas, annular upper and lower plates for the stator which are spaced apart to provide a lateral space contiguous with the space between the plates of the impeller, blades mounted be-- tween the plates of the stator which effect a shearing of the liquid discharged outwardly from the impeller, the peripheral portion of the stator being spaced inwardly from the container and curved downwardly to direct the liquid from the stator in an outward and downward direction, and an annular lip over the space between the impeller and the stator to suppress upward escape of fluids.
2. Apparatus according to claim 1 which comprises an annular lip attached to the stator and extending a short distance inwardly over the upper plate on the impeller.
3. Apparatus for the dispersion of a gas in a liquid which comprises an impeller-stator unit, the impeller having removable upper and lower rings which are substantially parallel and generally horizontally disposed and impeller blades mounted between the rings, said rings having upper and lower inlet openings for gas and liqm'd at their centers respectively which are variable on changing said rings, upper and lower impeller plates attached to the blades and concentrically disposed with respect to said rings,
a space therebetween, the stator having upper and lower plates which are curved downwardly and spaced apart, the space being contiguous with the space of the impeller, the impeller plates and rings being mounted exteriorly of the impeller blades and disposed centrally of the stator plates, upper and lower annular spaces between the plates of the impeller and the plates of the stator, a lip over the space between the upper plates of the impeller and the upper plates of thestator to prevent an undue passage of gas through the space, and a container in which the unit is mounted having a wall portion spaced from the peripheral portion of the stator, whereby rotation of the impeller sucks liquid and gas through the openings and discharges a mixture thereof through the space between the. stator plates and in the direction of the container wall.
prises a lip attached to the stator which extends over the space between the stator and the impeller.
6. Apparatus according to claim 3 which com-- prises an impeller with the peripheral portion of the blades and plates curved downwardly and the blades inclined.
KENNETH STERLING VALENTINE.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 423,285 Smith et a1 Mar. 11, 1890 706,473 Low Aug. 5, 1902 1,768,956 Johnson July 1, 1930 1,976,956 MacLean y Oct. 16, 1934 1,988,766 Aldridge Jan. 22, 1935 2,024,509 Chiquoine Dec. 17, 1935 2,159,988 Hasche May 10, 1939 2,246,560 Weinig et a1 June 24, 1941 2,377,937 Hervert June 12, 1945 2,542,031 Humfeld et a1 Feb. 20, 1951