US 3828929 A
Description (OCR text may contain errors)
United States Patent [1 Hickey, Jr. a
n1] 3,828,929 [451 Aug. 13, 1974 HOMOGENIZING METHOD AND APPARATUS-  Inventor: William E. Hickey, Jn, West Hartford, Conn.  Filed: 4 Jan. 22, 1973  Appl. No.: 325,135
 US Cl 210/70, 210/84, 210/219, 2l0/5l2,415/l,'415/116  Int. Cl B0ld 21/26  Field of Search 55/17; 210/59, 70, 83,
210/84, 206, 208, 219, 319, 512; 259/19, 21, 22, 23, 24;41.5/l15, 116,122 A, DIG. 1,1
 References Cited UNITED STATES PATENTS 3,s9s,392 7/1971 Markel ..210/s4 3,660,285 5/1972 Markel 210/84 3,743,095 7/1973 Mensing et a1. 210/84 Primary Examiner-Charles N. Hart Assistant Examiner,Mukai, Robert G.
Attorney, Agent, or Firm-Prutzman, Hayes, Kalb, ilto I ABSTRACT A method and apparatus for treating flow media at a pumping'station wherein an additive is mixed with the flow media at the pumping station and conveyed thereby to a separating station where the conveyed material is subjected to centrifugal force to at least partially separate the material into portions of different specific gravity. A separated portion of the material is removed downstream of the separating station.
21 Claims, 6 Drawing Figures PATENIED I 31974 SHEEI 2 BF 2 R E L L E P M STAT ON PUM NG HOMOGENIZING METHOD AND APPARATUS This invention generally relates to apparatus and processes for material handling and particularly concerns an apparatus and method for homogenously mixing large volumes of different material and thereafter separating and removing at least a portion of the homo'genous mixture or composite of the mixed materials'.
A primary object of this invention is to provide a new and improved apparatus particularly suited for high speed operations and high volume capacities to effect at a pumping station efficient mixing of flow media and a selected additive in a highly diffused separable homogenous composite and to thereafter separate a portion of the composite downstream of the pumping station, for removal from the remainder of the composite.
Another object of this invention is to provide a new and improved apparatus of the type described of significantly simplified construction particularly suited for use in a variety of applications having requirements for high volume processes on an uninterrupted flow basis undereffectively controlled conditions.
A further object of this invention is to provide such a new and improved apparatus for processing composites of fluids as well as solids or fluid and solid admix tures in effectively controlled proportions.
Another primary object of this invention is to provide a new and improved method of treating a material prior to conveying the treated material downstream for separation of at least a portion of the treated material and which is particularly suited for applications having high energy input and high operating speed requirements.
Another object of this invention is to provide such a new and improved method particularly suited for continuous high volume industrial processes.
A further object of this invention is to provide such a new and improved method which effectively controls input and output of materials to be physically mixed in homogenous proportions and also ensures a smooth continuous process in physically conveying the homogenous composite to a separating station on a continuous feed basis for selective removal of a portion of the conveyed composite.
A still further object of this invention is to provide such a method which may be used in a variety of different applications for handling different combinations of fluids or combinations of solids as well as combinations of fluids and solids and which provides for efficient and economical separation of a selected portion of the composite without requiring complicated and expensive chemical processing equipment.
Other objects will be in part obvious and in part pointed out in more detail hereinafter.
The invention accordingly comprises the several steps and the relation of one .or more of such steps with respect to each of the others and the apparatus possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure which also sets forth an illustrative embodiment of the apparatus employed in this invention indicative of the way in which the principle of this invention is employed.
In the drawings:
FIG. 1 is a side view, partly broken away and partly in section, of an axial flow unit at a pumping station incorporated in this invention;
FIG. 2 is a fragmentary schematic diagram, partly in section, showing components of a processing system incorporating the method and apparatus of this invention;
FIG. 3 is an axial end view showing a blade profile projection of the axial flow unit used at the pumping station of the processing system of FIG. 2;
. FIG. 4 is an axial end view showing a blade profile projection of an axial flow unit used at a separating station of the processing system of FIG. 2;
FIG. 5 is a side view, partly broken away and partly in section, showing an additive collection ring which is externally mounted on a rotor of the axial flow unit of FIG. 1; and
FIG. 6 is a diagrammatic flow profile characteristic of the axial flow type unit used in the illustrated embodiment of this invention.
Referring to the drawings in detail wherein a preferred embodiment of this invention is shown for illustrative purposes, unit 10 is an axial flow pump which may be either a single stage unit or multiple stage unit with each. unit having a cylindrical rotor 12 which is fragmentarily shown in half-section in FIG. 1. Impeller blades such as the one shown at 14 in FIG. 1 provide propulsion for material in a flow passageway through rotor 12 in the axial direction of arrow 16 from an inlet end of the unit, not shown, to an outlet end of the unit at the left-hand side of rotor 12 in FIG. 1. In FIG. 3, three equally spaced helical impeller blades 14 are shown providing an axially unobstructed flow passageway through rotor 12 although it is to be understood that this invention is not limited to such specific impeller arrangement. Rotor 12 is shown mounted for rotation within a cylindrical chamber of a housing generally designated 18. Units of this general type are normally powered and require a suitable power source such as a motor, not shown, for rotating an input shaft, not shown, drivingly connected to a drive gear 20 shown in mesh with driven ring gear 22 secured by bolts such as at 24 to an outside wall of the rotor 12. As fully described in Harvey E. Richters copending US. Pat. application Ser. No. 236,433 filed Mar. 20, 1972, entitled Improved Mechanical Seal, and assigned to the assignee of this invention, housing 18 provides mountings for drive shaft bearings 26 within housing gear casing 28 and also for bearings such as at 30 supporting the rotor 12 for rotation about a rotational axis generally designated X-X. The above referenced patent application more fully describes the housing and rotor construction of that embodiment shown in FIG. 1, and the subject matter of that application is incorporated herein by reference.
It should be noted that annular end mounting flanges such as 34 are suitably secured by a machine bolt, not shown, to each axial end of the housing 18 to maintain a seal assembly such as at 36 in operative association with the rotor 12 within enlarged annular chambers as at 38 which will be understood to circumferentially extend around the axial end portions of rotor 12. The illustrated left-hand axial end of rotor 12 is provided with a seal mating ring 40 shown secured on the lefthand portion of rotor 12 (FIG. 1), and a pair of 0 ring seals 42, 42 will be understood to extend continuously around the outer periphery of rotor 12 with a desired radial interference-fit to provide a fluid-tight seal, with each ring seal 42, 42 being received within recessed grooves 44, 44 in seal mating ring 40. Seal mating ring 40 is drivingly connected to the rotor by removable retaining pins such as shown at 46, and pins 46cooperate with a retaining ring 48 to releasably secure the seal assembly 36 in a position on the rotor 12. Undesired passage of oil, water, and other contaminants into. chamber 38 is controlled by a pair of ring seal subassemblies 50, 52 secured to housing 18 and presenting oppositely facing radial surfaces for sealing engagement with an adjacent side of seal mating ring A controlled homogenous mixing process for various combinations of fluids or solids or fluid and solid composites is provided in an apparatus particularly suited for continuous high volume operation. As described in Harvey E. Richters copending US. Pat. application Ser. No. 280,675 filed Aug. 14, 1972, entitled Additive Diffusor and assigned to the assignee of this invention, an additive diffusor 53 is provided, preferably in each impeller blade 14, to disperse a selected additive in controlled proportions relative to the flow media passing through the rotor 12. Diffusor 53 may be employed in different ways, e.g., in dispersing solid particulate matter into a sludge of flowable material passing through rotor 12, or in mixing different fluids such as a gaseous additive to be hoinogenously mixed together with a liquid media in the passageway of rotor 12. While it is intended that each of the impeller blades 14 are preferably provided with an additive diffusor, for purposes of explanation, it will be sufficient to describe only one shown for blade 14 as illustrated in FIG. 1.
In the specifically illustrated embodiment, rotor impeller blade 14 (FIG. 1) extends from an inside rotor wall 54 (along line 56) to provide a free edge 58 on blade 14 disposed radially inwardly of wall 54 such that blade 14, when rotated, acts as a screw propeller to propel flow media through the rotor 12..Blade 14 is preferably helical in shape and includes a trailing downstream edge 60 which is directed radially outwardly from an apex 62 of the blade 14 toward inside rotor wall 54.
This blunt downstream trailing edge 60 of impeller blade 14 provides for cavitation in the region of the flow passageway immediately adjacent the edge 60 at a predetermined rotor speed, and a plurality of dispersion outlets are shown such as at 64 formed in the downstream trailing edge surface of the impeller blade. Each dispersion outlet 64 is connected by an individual passageway 66 to a common internal manifold 68 formed inside blade 14 which leads toward its root portion where the blade 14 merges with the inside wall 56 of rotor 12. At the rotor of the blade 14, a valve body 70 is shown defining a valve chamber 72. Chamber-72 communicates with manifold 68 through an outlet port 74 and connects to the chamber 38 of housing 18 via an inlet port 76 in valve body 70 and a communicating opening 78 in the seal mating ring 40.
Chamber 38 may conveniently serve as an additive accumulator chamber for supplying various selected additives to the flow passageway of rotor 12. For controlling additive flow through the above described passage means between chamber 38 and the outlets 64, a ball check valve member 80 is received in the valve chamber 72 and is biased by a spring 82 radially inwardly against a valve seat surrounding outlet port 74 and into its illustrated normally closed flow control position.
Servicing the additive diffusors for each impeller blade 14 is a common additive collection ring 84 secured by any suitable means, not shown, to circumferentially extend about the seal mating ring 40. Upon rotation of rotor 12, additive within the accumulator chamber 38 will be collected from chamber 38 by raised vanes 86 (best seen in FIG. 6) formed on collection ring 84 with openings facing in the direction of rotation. The vanes 86 positively direct the additive into a common accumulator groove 88, which will be understood to circumferentially extend around the outer periphery of the seal mating ring 40, and through each of the plurality of openings such as illustrated at 78 in the seal mating ring 40 and into each valve chamber 72 of the impeller blades 14. If desired, a suitable coupling 90 to a supply conduit 92 may be secured to the housing 18 for supplying additive (through a connecting passage therein such as at 94) into the accumulator chamber 38. The illustrated arrangement obviously may be varied and tailored to' different types of additives being supplied, depending on whether the additive is a gas, liquid or solid and the nature of the solid additive if such is being used in the application of this invention. a
The cavitation region behind each impeller blade 14 provides a suction force at a predetermined rotational speed of the rotor l2 as flow media passes over opposite sides of the blades 14, and centifugal force developed by rotor rotation causes the ball check valve member to automatically move radially outwardly against the bias of its spring 82 to permit additive in chamber 38 to be collected and positively directed by the additive collection ring 84 into the common manifold 68 and through the connecting individual passages 66 to each of the dispersion outlets 64.
By such construction, uniform distribution of additive through each ball check valve of the respective impeller blades 14 and into their manifold 68 is provided to permit the additive to be forced out the dispersion outlets 64 under suction force and dispersed into the flow passageway in the rotor in a fan-like continuous sweeping action, providing a very effective spiralling turbulent mixing of the additive'with the flow media. As the rotor 12 slows down at shut-off the cavitation effect is reduced to minimize the pressure differential between the chamber 38 and the dispersion outlets, and the centrifugal force is diminished whereby the spring 82 automatically returns its ball check valve member 80 into normally closed flow control position. Any undesired accumulation of flow media within the accumulator chamber 38 is effectively prevented vto protect the integrity of the additive composition in addition to protecting the seal area about the outer periphery of the rotor.
Turning now to the system incorporating the processing method and apparatus of this invention for, mixing different materials into a homogenous separable composite of the additive and the flow media and thereafter separating and removing at least a portion of the composite under high operating speed and high volume throughput conditions, the lead and pitch of each of the described impeller blades 14 is selectively dimensioned and contoured such that a vigorous propelling effect is produced by the pumping unit 10 to mix the additive with the flow media received, e.g., from supply line 98 (FIG. 2) within the pumping station 100 and to additionally drive the resulting homogenous composite downstream through a connecting pipeline 102 in a smooth powerful thrusting flow toward a separating station generally designated 104.
By virtue of the disclosedconstruction, the total system is particularly suited to extract selected specific gravity masses from the total matter being mixed and transferred. An example would be in providing an effective solution to separating out a relatively heavy precipitant in a high volume chemical process resulting from the mixing of a selected additive and flow media at the pumping station 100. In short, the fluid flow unit at the upstream pumping station 100 supplies sufficient kinetic energy required to transport the total mass through the entire system while the secondary or downstream fluid flow unit at the separating station 104 provides sufficient centrifugal energy required to effectively arrange different specific gravity elements of the total mass in a manner proportional to the radius of the connected pipeline.
To effect efficient separation of the composite materials while operating at speeds and throughput volumes tions of the materials to be processed, the separating type similar to unit 10. That is, the units of both-the pumping and separating stations 100 and 104 exhibit similar flow profiles with axial velocity output (V,,) characteristics of generally proportional magnitude and direction relative to their respective pipeline cross sections as diagrammatically represented in FIG. 6. In the specifically illustrated embodiment of this invention, unit 10 is an axial flow device as previously described and the separating station unit also is preferably an axial flow device having a blade projection such as illustrated in FIG. 4 wherein the impeller blades 106 at the separating station 104 are of a modified lead and pitch arrangement in relation to blades 14 0f the pumping station unit shown in FIG. 3 but without any additive diffusors being provided in the impeller blades 106. The impeller blade construction of the separating station unit is designed to provide an axial flowpumping rate through the pipeline system less than that of unit 10 of the pumping station while imparting a significantly greater centrifugal force'on the conveyed mixture upon its being received within the flow passageway of the separating station 104 whereby its blades 106 each act on a substantial length and perimetrical depth of the column of mixture conveyed to the separating station 104.
To facilitate extraction of a desired specific gravity mass or portion of the conveyed mixture, a plenum chamber 108 is shown intermediate the pumping and separating stations 100 and 104 in communication with the interconnecting pipeline 102. Plenum chamber 108 is designed to provide appropriate low and high pressure regions upstream of the separating station 104 to stabilize high throughput volumes of mixed materials conveyed by the pumping station and to make the system independent of normally encountered pressure fluctuations. The disclosed system is totally independent and needs no other sundry mechanisms, vacuum techniques and other conventional equipment normally masses involved into separate portions based on their specific gravities.
More specifically, variation in specific gravities of solids, liquids and gases which may be transported through pipeline 102 and the vortical motion which is imparted by unit 10 to the flow media causes it to be arranged in a predictable manner inside pipeline 102 due to the velocity diagram (FIG. 6) and flow profile of unit 10 at the pumping station whereby the location of the different specific gravity massed being driven through pipeline 102 is a direct function of the radius of the pipeline 102 with theheavier specific gravity matter being arranged along the outer radial areas.
Assume that shaded section A represents a volume of mass transported through a completely filled pipeline 102 in one revolution of pump rotor 12 under given steady flow conditions wherein the downstream backpressure and rotational rotor speed are relatively constant. To stabilize the core of the conveyed mixture and thereby facilitate its extraction in a manner related to its different specific gravity masses, the volume of annular section B of plenum chamber 108 is designed larger than the volume of section A and plenum section C'is somewhat smaller in volume than section B and in coaxial alignment therewith to provide a high pressure zone, represented by section B, within plenum chamber 108 surrounding a relatively low pressure zone (section C) wherein lower specific gravitymasses are forced downstream along the central portion of pipeline 102 through its plenum chamber 108.
By such plenum design, pressure variations across a section of pipeline 102 are significantly more uniform since backpressure increase due to the change in direction of mass flow is absorbed in plenum chamber section B and variationsin pressures due to the mass separating or extraction effect of plenum chamber 108 are also dampened in its large volume section B. As mentioned, plenum chamber 108 additionally serves to augmer t the separation of masses of different specific gravities which actually takes place in a transitional region between section lines D-D and E-E. In this transitional region, line pressure increases radially and provides a compressed cone effect such as depicted by broken lines at 109, allowing lower backpressures along the center portion of chamber 108 while the change in velocity direction as indicated by lines 111 and reduction in its axial magnitude creates higher pressures along the outer perimetrical depth of the diverging input end of chamber 108 to stabilize the separation process by surrounding the centrally arranged lighter specific gravity masses passing through chamber 108 within the described surrounding high pressure zone (section B) while also allowing the higher specific gravity masses with their relatively high kinetic energy and centrifugal velocities to easily pass around the outside of cone 109 into the surrounding high pressure zone of chamber 108. If desired, an annular manifold, not shown, may be used in the transitional region of chamber 108 to promote separation of the different specific gravity masses. It is to be understood that the described system may be designed for laminar flow of the lower specific gravity masses through the center of plenum chamber 108 thereby significantly stabilizing the core of the mass flow. While the diverging input end of chamber 108 may reduce the critical Reynolds number, practically all cases of fluid flow through the surrounding high pressure outer zone of chamber 108 will be in the turbulent-flow region.
Accordingly, the flow media to be treated is continuously passed from supply line 98 through the pumping station 100 and a supply of a selected additive is uninterruptedly diffused into the flow passageway during rotor rotation to effect a homogenous mixing. The pumping action of the pumping station unit is augmented by the propulsive effect of the separating station unit to physically convey the mixture through pipeline 102 and its plenum chamber 108 to the separating station unit. lts impeller blades 106 are driven at a sufficient speed to centrifugally force that portion of the mixture of maximum specific gravity radially outwardly toward the inside wall 113 of the separating station rotor 110 (preferably having an inside diameter equal to that of plenum chamber 108). The centrifugate assumes a generally uniform cylindrically profiled form which is simultaneously driven downstream along the inside wall 112 of a connecting pipeline 114 by the propelling effect of the separating station unit. The passageway in pipeline 114 is preferably uniform and coaxially aligned and coextensive with the flow passageway of the rotor 110, and the heavier portion of the centrifuged mixture is axially forced downstream into a zone of pipeline 114 established by its maximum inside diameter and a radially inwardly disposed outside surface of a concentric conduit 116 of reduced diameter which will be understood to be mounted in coaxial downstream relation to the flow passageway extending through the separating station rotor 110. Lighter specific gravity. portions of the centrifuged mixture accordingly will be forced into the reduced conduit 116 centrally disposed within pipeline 114, and the centrifugate may be readily removed at least in part by the continued pumping action of the separating station unit forcing the higher specific gravity portion into a tributary conduit shown at 118 for suitable disposition further downstream.
In summary, it will be evident that the apparatus and method of this invention is particularly suited for a variety of different industrial processes. For example, where it is critical to obtain a change of state of chemicals being processed such as a liquid and a gas to form a liquid of different physical and chemical properties and a solid precipitant, e.g., or to form different liquids of different specific gravity, the apparatus and method of this invention is particularly suited to achieve such purposes. The disclosed apparatus and method may achieve such purposes in a controlled manner. The speed of rotation of the pumping and separating station units are designed to be independently and selectively controlled to correspondingly regulate the process, the input of diffusable additive, the degree of centrifugal force to be applied to the conveyed homogenous mix-- ture, the desired time delay for any desired reaction, the desired time delay for effecting flow between the pumping andseparating stations, etc. The described the primary separating force while augmenting the axial pumping force of the pumping station unit and forcing'the separated mixture portions downstream for removal. The method of this invention supplies its own motion transmission and flow regulation without relying on any weirs and without any gravity or vacuum methodsof separating or drawing off gases, liquids or solids into separate passageways. In addition, if the input'chemicals vary somewhat in consistency, the combination of the disclosed axial flow units of similar type effectively minimize such variations to a significant extent by effective mixing and homogenization of all elements at the pumping station thereby ensuring uninterrupted flow without substantial variations in construction of the components required provides a significantly simplified system wherein the pumping station unit provides the mixing action and also the basic pumping force. The plenum chamber 108 augments the extraction action of the separating station while further minimizing and accommodating line pressure fluctuations, The separating station unit provides proportion or the type of chemicals in a continuous process that is not believed to be normally feasible by the application of conventional teachings.
As will be apparent to persons skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without departing from the teachings of the present invention.
1. A method of treating material at a pumping station of a pipeline system and withdrawing a portion of the treated material downstream from a separating station of the pipeline system comprising the steps of supplying the material to be treated to the pumping station, supplying a diffusible additive to the material at the pumping station, mixing the material and the additive at.the pumping station to form a homogenous separable composite of the material and the additive by applying vortical motion to the composite by an axial flow pump at the pumping station, conveying the homogenous composite in the pipeline system from the pumping station to the separating station, stabilizing the flow of the conveyed composite upstream of the separating station by passing it through a plenum chamber having a diverging inlet whereby a core portion of the composite being conveyed in the pipeline system to the separating station is surrounded by a generally uniform cylindrical profiled centrifugate of the conveyed composite under high pressure relative to that of the core portion of the conveyed composite, applying a centrifugal force to the conveyed composite at the separating station to at least partially separate the composite into portions of different specific gravity, and removing a separated portion of the composite.
2. The method of claim 1 wherein the conveyed composite is a homogenous admixture of fluids.
3. The method of claim .1 wherein the conveyed composite is a homogenous mixture of solids.
4. The method of claim 1 wherein the conveyed composite is a homogenous fluid and solid mixture.
5. The method of. claim 1 wherein the conveying of the composite is provided by a pumping action of the pumping station.
6. The method of claim 1 wherein the application of centrifugal force at the separating station is provided by an axial flow pump having a generally cylindrical rotor with impeller means mounted on and projecting generally radially inwardly from an inside wall of the rotor.
7. The method of claim 6 wherein the centrifugal force is applied by rotating the conveyed composite in the axial flow pump at a speed sufficient to force the centrifugate into a generally uniform cylindrically profiled form, and wherein the removing of a separated portion of the mixture is effected by pumping its separated portions respectively through concentric conduits disposed downstream of the separating station in coaxial alignment with the generally cylindrical pump rotor.
8. The method of claim 6 wherein the mixing of the material and the additive at the pumping station is provided by a second axial flow pump having a cylindrical rotor with impeller means mounted on an inside wall of the rotor, and wherein the conveying of the composite of the material and the additive is jointly provided by the first and second axial flow pumps through a coaxial interconnecting pipeline.
9. The method of claim 8 wherein separation of the composite and removal of a separated portion thereof is controlled by maintaining the axial flow pump of the separating station at a pumping rate less than that of the axial flow pump of the pumping station.
10. The method of claim 1 wherein the mixing of the material and the additive at the pumping station is provided by an axial flow pump having a generally cylindrical rotor with impeller means mounted on and projecting generally radially inwardly from an inside wall of the rotor.
11. The method of claim 10 further including the step of regulating additive input by controlling the rota tional speed of the pump rotor during mixing of the material and the additive at the pumping station.
12. The method of claim 10 wherein the material to be treated is continuously suppliedto the pumping station, and wherein the diffusable additive is continuously supplied to the pumping station through a dispersion outlet in the impeller means of the axial flow pump.
13. A system for treating flow media with an additive.
comprising a conveying pipeline, a first axial flow pump unit in the pipeline conveying system, a second axial flow pump unit in the pipeline conveying system in downstream communication with the first unit, and a plenum chamber between said first and second units, the first unit including additive diffusing means for mixing an additive with flow media supplied to the first unit and a cylindrical rotor having an axial flow passageway therethrough with an impeller blade arrangement located in the passageway for effecting a turbulent mixing action to provide a homogenous separable composite of the flow media and the additive, said plenum chamber having a conical inlet extending in radially diverging concentric relation to the adjacent upstream flow passageway of the pipeline conveying system, and an outlet connected to the rotor of the second unit for stabilizing the flow of the composite input to the sec- 0nd unit, the second unit including a cylindrical rotor having an axial flow passageway therethrough with an impeller bladearrangement for centrifuging the stabilized composite received from the plenum chamber to at least partially separate the centrifugate for removal from the remainder of the centrifuged composite and means for removing said separated centrifugate from the remainder of the composite.
14. The apparatus of claim 13 wherein the rotors of the first and second axial flow units are independently controlled.
15. The apparatus of claim 13 wherein the first axial flow unit has a pumping rate greater than that of the second axial flow unit.
16. The apparatus of claim 13 wherein the plenum chamber includes a central core section having a crosssectional area which is approximately equal but slightly less than the cross-sectional area of the adjacent upstream flow passageway of the pipeline conveying system, the remaining portion of the plenum chamber surrounding its central core section having a crosssectional area which is greater than that of the adjacent upstream flow passageway of thepipeline conveying system.
17. The apparatus of claim 13 wherein the outlet of the plenum chamber and the rotor of the second unit are of generally uniform diameter.
18. The apparatus of claim 13 wherein the additive diffusing means includes an additive supply source, a dispersion outlet in an impeller blade of the first unit rotor, passage means connecting .the additive supply source with the dispersion outlet, and a valve control in the passage means and carried in the first rotor for controlling additive flow, the valve control means being movable from a normally closed flow control position to an open position responsive to application of centrifugal force upon rotor rotation.
19. The apparatus of claim 18 wherein regulation of the valve control is effected by variation in the centrifugal force applied by the first axial flow unit rotor to automatically proportion additive diffusion to the flow media being pumped by the first unit.
20. The apparatus of claim 18 wherein said impeller blade includes a downstream trailing edge surface, and wherein the dispersion outlet is formed in said downstream trailing edge surface adjacent a cavitation region created downstream thereof in the flow passageway upon rotor rotation.
21. The apparatus of claim 13 wherein the rotors of the first and second axial flow units and the plenum chamber are in coaxial alignment.