US3871625A

US3871625A - Continuous flow jet mixer

Info

Publication number: US3871625A
Application number: US386027A
Authority: US
Inventors: Hiroyuki Iwako
Original assignee: FUNKEN CO Ltd
Current assignee: FUNKEN CO Ltd
Priority date: 1971-07-24
Filing date: 1973-08-06
Publication date: 1975-03-18
Anticipated expiration: 1992-03-18

Abstract

A continuous flow jet mixer includes a tank into which liquid is constantly supplied tangentially, to flow annularly about a concentric inverted overflow cone. The circulating liquid rises to overflow the edge of the cone and flows downward and inward over it as a liquid film. A smaller upright cone spreader rotates therein on a central shaft. Particles of a material such as powder, introduced centrally downward onto the spreader, are centrifugally swirled onto and quickly dissolved in the descending liquid film. Supplemental centrifugal mixing is effected beneath the inverted overflow cone by a mixing disc, rotated on the same central shaft.

Description

United States Patent [191 Iwako Mar. 18, 1975 CONTINUOUS FLOW JET MIXER [75] Inventor: I I i royuki1wako,Tokyo,Japan Related US. Application Data [63] Continuation of Ser. No. 262,743, June 14, 1972,

abandoned.

[30] Foreign Application Priority Data July 24, 1971 Japan 46-54935 [56] References Cited UNITED STATES PATENTS 821,790 5/1906 Dorweiler 259/65 2,102,548 l2/l937 Stratford 259/8 X 3,029,069 4/1962 Cummings 259/4 3,599,938 8/l97l Anders.....' 259/7 FOREIGN PATENTS OR APPLICATIONS 677,401 1/1964 Canada Primary Examiner-Peter Feldman Assistant Examiner-Alan Cantor Attorney, Agent, or Firm-Cooper, Dunham, Clark, Griffin & Moran [57] ABSTRACT A continuous flow jet mixer includes a tank into which liquid is constantly supplied tangentially, to flow annularly about a concentric inverted] overflow cone. The circulating liquid rises to overflow the edge of the cone and flows downward and inward over it as a liquid film. A smaller upright cone spreader rotates therein on a central shaft. Particles of a material such as powder, introduced centrally downward onto the spreader, are centrifugally swirled onto and quickly dissolved in the descending liquid film. Supplemental centrifugal mixing is effected beneath the inverted overflow cone by a mixing disc, rotated on the same central shaft.

17 Claims, 1 Drawing Figure BACKGROUND OF THE INVENTION This invention relates to a continuous flow jet mixer wherein liquid is mixed with a downward jet of powder or other liquid, or both, continuously and evenly at a controlled rate of production.

It has heretofore been difficult to intermix certain materials, for example, powders, evenly in liquids, with the constant accuracy required for industrial and commercial uses. Irrespective whether batch or continuous mix was used, it has been difflcultto effect distribution of the material to be intermixed with the liquid with sufficient control as to avoid lumps of powder and other undesirable results.

SUMMARY OF THE INVENTION This invention has for its object the provision of a mixer for the precise control and thorough mixing and dissolving of inflowing materials, for example, powders which have a tendency to lump together. The purpose is to intermix a continuous downward flow of such a material, or several materials, into the surface of a constantly flowing liquid film.

In a mixer which embodies this invention, the liquid, for example, water, into which the other material is to be mixed, is admitted tangentially into an annular chamber along whose center is an inverted truncated cone. The liquid circulates around the outer surface of the cone and rises to overflow inward and downward as a film on the inner conical surface. In the center of the inverted truncated cone is a revolving small cone spreader, powered by a central vertical shaft. Onto the upper surface of the spreader impinges a downflowing supply of powder, for example, or other liquid material to be mixed. Rotation of the spreader swirls and centrifugally disperses this powder or other material evenly in the downflowing film of liquid within the inverted cone, so that its particles are separately suspended in it, and, if soluble, are readily dissolved. At the base of the truncated cone, the solution or mixture descends onto a horizontal plate rotating on the same central shaft, and it is impelled centrifugally, through mixing pins, in a central tapering lower shell, or vessel, from which it is discharged.

The following advantages are obtained:

1. The machine produces a continuous precisely controlled solution or suspension at a constant rate. No supplemental mixing devices are required.

2. Since the material to be intermixed or dissolved is evenly dispersed into a downflowing film, the mixing and dissolving and other chemical reactions, if any, occur very quickly.

3. The machine aovids negative pressures which tend to cause such conditions as adhesion of the particles to be mixed or the absorption of dust and foreign matter.

4. Modern types of control, such as a computer punch card system and the like, can be employed to control the actual flow, and the flow rates and proportions with high accuracy.

5. The machine is simple in construction, easy in its maintenance, relatively free from trouble and of high reliability.

A preferred embodiment of the invention will now be described, reference being made to the accompanying Drawing.

BRIEF DESCRIPTION OF THE DRAWING The Drawing is an elevational view, partly in section, of a preferred embodiment of the invention together with a schematic presentation of a control system therefor.

DESCRIPTION OF THE PREFERRED EMBODIMENT The mixer shown in the drawing comprises a cylindrical tank 2 for containing liquid. Its cylindrical wall is provided, at a relatively low level, with a tangential inlet 1. Within the tank 2 is a concentric inverted truncated overflow cone 3 whose upper edge is above the liquid inlet 1, the inner wall of the overflow cone 3 discharging downwardly through a central opening in the bottom of the tank 2.

Extending through the top of the tank 2 is a downwardly directed central flow inlet 4, which may provide for the inflow of powder or other material in a downward jet. Directly beneath it, at a level below the upper edge of the overflow cone 3, is a small diameter cone spreader 6, secured onto the upper end of a central vertical rotary shaft 5, which extends downward and through the cone 3 and therebelow as will be described. At a level spacedly below the bottom of the cone 3 and tank 2, a mixing disc 7 is mounted onto the shaft, the disc being larger in diameter than the lower end of the cone 3, which opens onto it. A plurality of short pins 8 are mounted on the upper surface of the disc 7, arranged in circles to project upward in the space below the bottom of the tank 2. At different radial spacings, close to the spacings of the pins 8, are circles of similar short stationery pins 9 mounted to project downward from the bottom of the tank 2 just above the outer edge of the disc 7, then to substantially intermesh with the pins 8. Outwardly-of the disc 7, guide vanes I0 project downwardly from the bottom ofthe tank 2 to direct the mixture downward.

Around these elements, beneath the tank 2, is a supplementary vessel, preferably in the form of an inverted cone shell 11. It surrounds the vanes 10 and slopes downward and inward toward a central mounting for the vertical shaft 5. Thereadjacent it is provided with an outlet through which the mixture produced by the invention is delivered. In the lower part of the shell vessel 11 is a rotating scraper blade 12 mounted on the shaft 5 beneath the disc 7. By a conventional electric motor and belt and sheave drive, the shaft 5 is driven from its lower end which projects beneath its mounting at the bottom center of the shell 11.

Liquid, for example water, supplied at a predetermined flow rate, as hereinafter described, flows into the tank inlet 1 tangentially, and circulates about the outer surface of the inverted overflow cone 3, to rise to its upper edge, which it overflowed. The overflowed liquid moves over the inner surface of the cone 3 in a spirally descending flow, to pass downward through the central opening at its base. The thickness of the liquid film will be a function of known factors; and it will be obvious that the liquid flow rate is to be controlled to maintain the film-like flow of the liquid. Considering, for example, the down feed through the inlet 4 of powdery material which is to be dissolved in liquid admitted through the inlet 1: as such liquid descends as a film on the inner surface of the overflow cone 3, particles of powder impelled by rotation of the spreader cone 6 will be thereby distributed evenly over at the descending liquid film. The rotating spreader 6 imparts a centrifugal force to the particles, which may already possess substantial energy by reason of being discharged downwardly in a jet through the inlet 4; and the kinetic energy of the whirling powder particles aids in their intermixture with and dissolving into the film of liquid. As the mixture descends onto the mixing disc 7, centrifugal force expels it through the adjacent pins 8 and 9.

This effects a second phase of intermixture and dissolving.

The apparatus which feeds and controls the feed through the inlets l, 4 will now be described. In a preferred embodiment, adapted for feeding of powder downwardly through a tapered bin shown uppermost in the drawings, there is provided at the base of such conventional bin a motor driven feeder for powder generally designated PF which leads downwardly into the top inlet 4 which has been described. A motor driven feeder for the liquid generally designated LF includes a conventional supply tank and valves, not otherwise described, and pumps such liquid under positive feed control into the tangential inlet 1 of the tank 2. The supplies of powder and liquid are delivered in amounts precisely proportional to the speed of motors therefor, as shown on the drawing.

Connected to the powder feeder PF and the liquid feeder LF are pulse generators PG and LG respectively. These generate pulse signals having signal rates proportionate to the amounts being fed by the feeders PF, LF. The pulse generators PG, LG are connected to a control unit U which in turn connects to the motors of the feeders PF, LF.

On the control unit U, which may be located remote from the mixing apparatus described, are setting counters for powder PC and for liquid LC. Indicators of the flow rates D/A signalled by the powder pulse generator PG and the liquid pulse generator LG are also provided, designated PP and LD respectively. Also provided are integrating meters PI, Ll of the pulses as signalled for powder delivery and liquid delivery respectively. All these controls are connected in conventional circuitry through comparators, to a master timer T which receives a master pulse. The pulse generators for powder and liquid PG, LG assure proportional controlling of both feed systems from a master pulse system. The feed rates are readily read from the indicators PP, LD and the total performance from the integrating meters PI, LI. Alternately, punch card or computerized controls may be added.

So accurate is the proportional control, and so even and thorough is the distribution of material such as powder supplied through the downward inlet 4, into the descending film of liquid on the inner surface of the overflow cone 3, that relatively large amounts of powder may be intermixed without difficulty. There being no substantial variations in flow rates, nor negative pressures which would cause powder particles to adhere, and the powder particles being preliminarily protected from dust and moisture absorption, the mechanism defined results in such an even intermixture in the liquid film, that, aided by the second phase of mixing on the disc 7, relatively large amounts of powder can be dissolved into the liquid with assurance of uniformity and freedom from powder lumps.

While the invention has been described with reference to the embodiment shown in the drawing, variations to suit particular purposes will be obvious to those skilled in the art.

I claim:

1. A continuous flow mixer comprising a tank having an outer wall formed about a central vertical axis, a tangential inlet into said wall,

an inverted truncated overflow cone disposed in and concentric with said tank, whereby to provide an annular space within which liquid from said inlet is circulated, the overflow cone having an upper edge above the level of the tank wall inlet and having an inner conical surface and a central outlet at the tank bottom, whereby liquid circulating in said annular tank portion may rise to and overflow the upper edge of the overflow cone and descend as a film over said inner conical surface,

top central inlet means to admit downwardly into I said tank along its axis a material ofa type capable of being dispersed into said liquid, and

means beneath said inlet and operating along said central axis to disperse and distribute such material, so admitted downwardly, centrifugally from said axis, whereby to cause its continuous and even intermixture into such liquid film descending on the said inner conical surface.

2. A continuous flow mixer as defined in claim 1, wherein the means to disperse is a spreader cone mounted on a powered shaft positioned on said central axis.

3. A continuous flow mixer as defined in claim 1,

the means to disperse being mounted atop a vertical powered shaft extending upward along said axis from a level beneath the bottom of the tank, together with a vessel beneath said tank and surrounding a portion of the shaft at said level, and

disc-like means, mounted on said shaft within said vessel beneath the outlet of said overflow cone, to receive and centrifugally dispel a mixture descending therefrom.

4. A continuous flow mixer as defined in claim 3,

the said disc-like means having, radially outward from the outlet of said overflow cone, intermeshing pin means to further intermix a mixture discharged on said disc-like means from said overflow cone outlet.

5. A continuous flow mixer as defined in claim 1,

the means to disperse being mounted atop a vertical powered shaft extending upward along said axis from a level beneath the bottom of the tank, to

electrically powered means to feed a material to be intermixed with such liquid downwardly to the top central inlet means,

and control means to fix precise delivery rates of said liquid feed means and said feed means for such material to be intermixed therewith, and their proportioned delivery.

7. A continuous flow mixer comprising:

a tank having an outer wall and an inlet into said wall;

an open top overflow vessel disposed within said tank to provide an annular space between the tank wall and the vessel, into which space liquid entering from said inlet can circulate, the overflow vessel having an upper edge, a bottom outlet and an inner surface shaped to form a descending film of liquid which has circulated in said annular space and has risen to and overflown the upper edge of the overflow vessel, wherein the inner surface of the overflow vessel converges in the downward direction;

material inlet means to admit into said tank and into said overflow vessel a material of a type capable of being dispersed into said liquid; and

first dispersing means adjacent said material inlet means to disperse and distribute the admitted material into the descending liquid film along the inner surface of the overflow vessel.

8. A continuous flow mixer as in claim 7 including a collection vessel disposed beneath said tank and beneath said bottom outlet of the overflow vessel to admit the mixture of material and liquid descending along the inner surface of the overflow vessel and exiting therefrom through said bottom outlet thereof, and second dispersing means disposed within said collection vessel in the path of the exiting mixture from the overflow vessel for dispersing said mixture.

9. A continuous flow mixer as in claim 8 wherein said first and second dispersing means comprise centrifugal dispersers.

10. A continuous flow mixer comprising:

a tank having an outer wall and an inlet into said wall;

an open top overflow vessel disposed within said tank to provide an annular space between the tank wall and the vessel, into which space liquid entering from said inlet can circulate, the overflow vessel having an upper edge, a bottom outlet and an inner surface shaped to form a descending film of liquid which has circulated in said annular space and has risen to and overflown the upper edge of the overflow vessel;

a material inlet means to admit into said tank and into said overflow vessel a material of a type capable of being dispersed into said liquid;

first dispersing means adjacent said material inlet means to disperse and distribute the admitted material into the descending liquid film along the inner surface of the overflow vessel;

21 collection vessel disposed beneath said tank and beneath said bottom outlet of the overflow vessel to admit the mixture of material and liquid descending along the inner surface of the overflow vessel and exiting therefrom through said bottom outlet thereof;

second dispersing means disposed within said collection vessel in the path of the exiting mixture from the overflow vessel for dispersing said mixture, said first and second dispersing means comprising centrifugal dispersers;

wherein said tank and overflow vessel are coaxial and wherein the inner surface of the overflow vesses converges toward said bottom outlet thereof,

11. A continuous flow mixer as in claim 10 wherein the inlet into the tank wall is disposed below the level of the upper edge of the overflow vessel.

12. A continuous flow mixer as in claim 11 wherein the overflow vessel is in the shape of a truncated inverted cone.

13. A continuous flow mixer as in claim 12 wherein the first dispersing means comprise a spreader cone mounted on a powered shaft extending along the axis of the overflow vessel, and wherein said material inlet means is positioned directly above said spreader cone.

14. A continuous flow mixer as in claim'13 wherein said second dispersing means comprise a rotating disc disposed below the bottom outlet of the overflow vessel and having a plurality of upwardly extending pins.

15. A continuous flow mixer comprising:

A tank having an outlet wall and an inlet into said wall;

material inlet means to admit into said tank and into said overflow vessel a material of the type capable of being dispersed into said liquid; and

first dispersing means adjacent said material inlet means to disperse and distribute the admitted ma terial into the descending liquid film along the inner surface of the overflow vessel, wherein the tank and the overflow vessel are coaxial and the inner surface of the overflow vessel converges in the downward direction.

16. A continuous flow mixer as in claim 15 wherein the inner surface of the overflow vessel is in the shape of a truncated inverted cone.

17. A continuous flow mixer as in claim 15 wherein the first dispersing means comprise a spreader cone mounted on a powered shaft extending along the com mon axis of the overflow vessel and the tank, and wherein said material inlet means is positioned directly above said spreader cone.

Claims

1. A continuous flow mixer comprising a tank having an outer wall formed about a central vertical axis, a tangential inlet into said wall, an inverted truncated overflow cone disposed in and concentric with said tank, whereby to provide an annular space within which liquid from said inlet is circulated, the overflow cone having an upper edge above the level of the tank wall inlet and having an inner conical surface and a central outlet at the tank bottom, whereby liquid circulating in said annular tank portion may rise to and overflow the upper edge of the overflow cone and descend as a film over said inner conical surface, top central inlet means to admit downwardly into said tank along its axis a material of a type capable of being dispersed into said liquid, and means beneath said inlet and operating along said central axis to disperse and distribute such material, so admitted downwardly, centrifugally from said axis, whereby to cause its continuous and even intermixture into such liquid film descending on the said inner conical surface.

3. A continuous flow mixer as defined in claim 1, the means to disperse being mounted atop a vertical powered shaft extending upward along said axis from a level beneath the bottom of the tank, together with a vessel beneath said tank and surrounding a portion of the shaft at said level, and disc-like means, mounted on said shaft within said vessel beneath the outlet of said overflow cone, to receive and centrifugally dispel a mixture descending therefrom.

4. A continuous flow mixer as defined in claim 3, the said disc-like means having, radially outward from the outlet of said overflow cone, intermeshing pin means to further intermix a mixture discharged on said disc-like means from said overflow cone outlet.

5. A continuous flow mixer as defined in claim 1, the means to disperse being mounted atop a vertical powered shaft extending upward along said axis from a level beneath the bottom of the tank, together with a vessel beneath said tank and surrounding a portion of the shaft at said level, the vessel having the form of an inverted cone shell and having a lower central mounting for said shaft and having adjacent to said mounting a discharge outlet.

6. A continuous flow mixer as defined in claim 1, together with electrically powered means to feed a liquid into the tangential inlet of the tank, electrically powered means to feed a material to be intermixed with such liquid downwardly to the top central inlet means, and control means to fix precise delivery rates of said liquid feed means and said feed means for such material to be intermixed therewith, and their proportioned delivery.

7. A continuous flow mixer comprising: a tank having an outer wall and an inlet into said wall; an open top overflow vessel disposed within said tank to provide an annular space between the tank wall and the vessel, into which space liquid entering from said inlet can circulate, the overflow vessel having an upper edge, a bottom outlet and an inner surface shaped to form a descending film of liquid which has circulated in said annular space and has risen to and overflown the upper edge of the overflow vessel, wherein the inner surface of the overflow vessel converges in the downward direction; material inlet means to admit into said tank and into said overflow vessel a material of a type capable of being dispersed into said liquid; and first dispersing means adjacent said material inlet means to disperse and distribute the admitted material into the descending liquid film along the inner surface of the overflow vessel.

10. A continuous flow mixer comprising: a tank having an outer wall and an inlet into said wall; an open top overflow vessel dIsposed within said tank to provide an annular space between the tank wall and the vessel, into which space liquid entering from said inlet can circulate, the overflow vessel having an upper edge, a bottom outlet and an inner surface shaped to form a descending film of liquid which has circulated in said annular space and has risen to and overflown the upper edge of the overflow vessel; a material inlet means to admit into said tank and into said overflow vessel a material of a type capable of being dispersed into said liquid; first dispersing means adjacent said material inlet means to disperse and distribute the admitted material into the descending liquid film along the inner surface of the overflow vessel; a collection vessel disposed beneath said tank and beneath said bottom outlet of the overflow vessel to admit the mixture of material and liquid descending along the inner surface of the overflow vessel and exiting therefrom through said bottom outlet thereof; second dispersing means disposed within said collection vessel in the path of the exiting mixture from the overflow vessel for dispersing said mixture, said first and second dispersing means comprising centrifugal dispersers; wherein said tank and overflow vessel are coaxial and wherein the inner surface of the overflow vesses converges toward said bottom outlet thereof.

14. A continuous flow mixer as in claim 13 wherein said second dispersing means comprise a rotating disc disposed below the bottom outlet of the overflow vessel and having a plurality of upwardly extending pins.

15. A continuous flow mixer comprising: A tank having an outlet wall and an inlet into said wall; an open top overflow vessel disposed within said tank to provide an annular space between the tank wall and the vessel, into which space liquid entering from said inlet can circulate, the overflow vessel having an upper edge, a bottom outlet and an inner surface shaped to form a descending film of liquid which has circulated in said annular space and has risen to and overflown the upper edge of the overflow vessel; material inlet means to admit into said tank and into said overflow vessel a material of the type capable of being dispersed into said liquid; and first dispersing means adjacent said material inlet means to disperse and distribute the admitted material into the descending liquid film along the inner surface of the overflow vessel, wherein the tank and the overflow vessel are coaxial and the inner surface of the overflow vessel converges in the downward direction.

17. A continuous flow mixer as in claim 15 wherein the first dispersing means comprise a spreader cone mounted on a powered shaft extending along the common axis of the overflow vessel and the tank, and wherein said material inlet means is positioned directly above said spreader cone.