US 3782697 A
In apparatus for dissolving and admixing components having a highly different specific gravity in liquid to highly viscous media, a blade wheel surrounded by a guide ring is used as a pumping member to create in the liquid medium a suction zone, which contains a discharge opening of a conduit for supplying the substances having a relatively low specific gravity. The supply conduit is provided at its end remote from the blade wheel with a feeder or the like for the powders, and its discharge opening is disposed within the guide ring and as close as possible to the revolving elements of the blade wheel.
Description (OCR text may contain errors)
United States Patent Karg Jan. 1, 1974  APPARATUS FOR DISSOLVING AND 2,878,969 3/1959 Griswold 222/193 ADMIXING COMPONENTS HAVING A g t avrs HIGHLY DIFFERENT SPECIFIC GRAVITY 2,704,206 3/1955 Crook 222/193 IN LIQUID TO HIGHLY VISCOUS MEDIA  Inventor: Roland Karg, Stuttgart, Germany Primary Examiner Robert Jenkins 73 Assignee: Dr. Karg GmbH, Stuttgart, Arwrney-lmirie & Smiley Germany  Filed: July 14, 1971  ABSTRACT  Appl- N05 162,452 In apparatus for dissolving and admixing components having a highly different specific gravity in liquid to  Foreign Application Priority Data highly viscous media, a blade wheel surrounded by a July 17 1970 Germany P 20 35 485 2 guide ring is used as a pumping member to create in the liquid medium a suction zone, which contains a  US. Cl. U 259,24 discharge opening of a conduit for supplying the sub- [SI] Int. Cl stances having a relatively low Specific g y The  Field of is I I I I n 259/97 7 8 23 supply conduit is provided at its end remote from the 6/ i h blade wheel with a feeder or the like for the powders, and its discharge opening is disposed within the guide  References Cited ring and as close as possible to the revolving elements of the blade wheel. UNITED STATES PATENTS 2,801,083 7/1957 Balassa 259/24 3 Claims, 2 Drawing Figures 74 1 -t-t 1, i'""* 30 APPARATUS FOR DISSOLVING AND ADMIXING COMPONENTS HAVING A HIGHLY DIFFERENT SPECIFIC GRAVITY IN LIQUID TO HIGHLY VISCOUS MEDIA SUMMARY OF THE INVENTION Apparatus for dissolving and admixing components having a highly different specific gravity by means of a pumping member consisting of a blade wheel surrounded by a guide ring. A conduit for supplying a substance to be introduced into a medium has a discharge opening disposed within the guide ring and close to the blade wheel.
The invention provides an apparatus for dissolving and admixing components having a highly different specific gravity in liquid to highly viscous media. A pumping member consists of a blade wheel, which is surrounded by a guide ring and creates in the liquid medium a suction zone, which contains a discharge opening of a conduit for supplying the substances having a lower specific gravity.
Known dissolving and mixing apparatus comprise a driven blade wheel, which is surrounded by a guide ring and which enforces a flow bf the media. Such apparatus may be used to subject liquids differing in viscosity and liquids together with solids, to homogenizing, emulsifying, dispersing and the like operations. These known apparatus have the disadvantage that it is impossible or very difficult to incorporate powders having very low specific gravities, such as soot, milk powder, aerosols or cocoa powder into a liquid component unless the mixing apparatus is placed on such a high level that the pumping member sucks air in the form of a vortexlike funnel and said air entrains the powder downwardly into the mixing head. That mixing operation has the disadvantage that air is also drawn into the mixing head and is finely dispersed in the mixed materials although this is not desired in many cases. In a mixing operation of this kind, the powders tent to clog so that a uniform disperson cannot be accomplished. Similar remarks will be applicable if liquid media having highly different specific gravities should be processed to form a homogeneous mixture.
Another known mixing apparatus comprises a pumping member in the form of a blade wheel which is surrounded by a guide ring and also comprises supply conduits which extend into the suction zone of said pumping member to supply air which is to be admixed to the mixture. This is accomplished in that the air supply conduits extend into the region in which a suction cavity is formed above the blade wheels. The discharge openings of these air supply conduits are disposed outside the guide ring which surrounds the blade wheel.
That known apparatus is satisfactory when it is desired to supply and admix air to a liquid but cannot be used to dissolve powders in liquids. It has been found that in such apparatus powders can be sucked and admixed only within the funnellike suction vortex formed during the operation of the blade wheel, which is dis-'-' posed slightly below the liquid level. The use of this apparatus inevitably results in an undesired admixing also of air. I r
It is an object of the present invention to eliminate these disadvantages and to provide a dissolving and mixing apparatus which is of the kind defined first hereinbefore and which is suitable for processing substances having a low specific gravity together with liquid or, if desired, viscous components.
According to the invention, the conduit for supplying powders to be dissolved is provided at that end which is remote from the blade wheel with a feeder or the like for the powders and the discharge opening of said conduit is disposed within the guide ring and as close as possible to the revolving parts of the blade wheel.
Due to this design, the substances having a low specific gravity can be sucked from an external location directly into the range of the mixing head so that they will be satisfactorily dissolved and/or admixed without a risk of an ingress of air. It has also been found that a clogging of powders will be entirely avoided in the operation of the novel apparatus, which is particularly desirable and suitable for the processing of powders. Besides, the substances having a relatively low specific gravity, particularly the powders, are sucked by the strong suction produced by the revolving blade wheel and together with the resulting liquid jet are uniformly dissolved or dispersed in the liquid fluid.
According to another feature of the invention, the suction conduit incorporates an additional handling device having an action similar to that of an ejector pump. Such an arrangement will result in an increased suction particularly in powders.
It is a further feature of the invention to provide an additional handling device in the;form of an injector which is fed by a high-pressure pump and wets or mixes the powders with the entraining liquid and supplies the liquid and powders to the blade wheel. That arrangement results in a particularly rapid processing of powders having a high tendency to stick or swell rapidly, such as dry pectin or polyelectrolytes.
According to a further feature of the invention, a mixing device is provided with a tube which carries the guide n'ng surrounding the blade wheel and said tube itself serves to suck or handle the substances which are dry or are wetted by or admixed to the entraining liquid. That design eliminates the need for a separate suction pipe.
Illustrative embodiments of the invention are shown by way of example in the drawings and will be described hereinafter.
In the drawings,
FIG. 1 is a side elevation showing a dissolving and mixing apparatus which comprises a rotating blade wheel that is surrounded by a guide ring, and a pipe which is disposed beside the means for driving the blade wheel and serves to suck powders.
FIG. 2 shows an embodiment which is similar to that of FIG. 1 but in which the tube which carries the guide ring surrounding the blade wheel constitutes also a suction tube for the powders.
With reference to FIG. I, a blade wheel 2 is surrounded by a guide ring 1 and suspended to be immersed in a liquid medium 3, which has been filled, e.g., into a container, not shown. The blade wheel 2 is operated by an electric motor 4 by means of a shaft which extends within a tube 5 which carries the guide ring 1. The carrying tube 5 is carried by the wall of the container or by other means. A suction pipe 6 extends beside the carrying tube 5 and is held by a flange 7, which is secured to the carrying tube 5 or the electric motor 4. The suction pipe 6 is provided with a shut-off valve 8 adjacent to the flange 7. The suction pipe 6 carries a feed hopper 9 for powders to be dissolved in or admixed to the liquid medium 3. During the operation of the blade wheel, the liquid 3 is sucked in the direction of the arrow 10 through a pre-arranged guide ring 11 and then through the guide ring 1 and is thereafter ejected with a high kinetic energy from the guide ring 1 or under the action of a second blade wheel from a tubular extension 13 so that a circulating motion and mixing operation are induced in the container. When the shut-off valve 8 is then opened, the powder is sucked from the hopper 9 through the suction pipe 6 into the range of the guide ring 1 and by the revolving blade wheel 2 is entrained in the jet of the liquid 3 which is ejected from the mixing head. During this operation, the powder is most finely dispersed in the medium 3 without any risk of an ingress of air because the mixing head and the lower opening of the suction pipe 6 may be sufficiently spaced below the liquid level 30. To improve the suction operation, an additional handling device 14 acting like an ejector pump may be provided in the suction pipe 6. That device is indicated in dotted lines.
According to FIG. 2., the powder to be dissolved or admixed is supplied from the hopper 9 through the suction pipe 6 to an injector 14, which is supplied through a port 15 with liquid from a high-pressure pump. The liquid sucks the powder and in the injector l4 entirely or partly wets the powder. The entraining liquid supplied through the port 15 then flows through the tube portion 6a into the interior of the carrying tube and by the suction of the blade wheel 2 and the discharge pressure of the injector 14 is introduced in the direction of the arrow 16 into the guide ring 1 and as in the embodiment shown in FIG. 1 is ejected from the guide ring 1 or its extension 13. In this embodiment too, the medium 3 enters in the direction of the arrow 10 the pre-arranged guide ring 11, which is connected by webs 11a to the carrying tube 5. The entraining liquid which enters the injector 14 through the port 15 may be taken in certain cases directly from the medium 3 or may be taken from an additional liquid source so that solutions may be diluted or concentrated. In the embodiment shown in FIG. 2, the funnel 9 may also be preceded by a shut-off valve, whoch is not shown.
The invention provides a most desirable apparatus for incorporating powdered substances having a low specific gravity into fluids having a liquid to highly viscous consistency. Alternatively, the suction conduit may be used to introduce liquids which have a much lower specific gravity than the liquid initially contained in the container, although the greatest advantage is afforded by the invention in the processing of powders together with liquid media.
What is claimed is:
1. Apparatus for dissolving and admixing components having a highly different specific gravity in liquid to highly viscous media comprising a pumping member which is adapted to be immersed in a liquid medium and which is composed of a blade wheel which is surrounded by a guide ring and serves to create a suction zone in said liquid medium, a conduit for supplying substanceswhich have a lower specific gravity than said liquid medium, said conduit having a discharge opening disposed in said suction zone, said conduit being provided at its end portion opposite to said blade wheel with means for feeding said substances thereto, means incorporated in said conduit for force-feeding such substances to the suction zone so that such substances enter the pumping member in reaction to the suction of the blade wheel and the discharge pressure of said feeding means, and said discharge opening at the other end of said conduit being disposed within said guide ring and close to said blade wheel.
2. Apparatus as set forth in claim 1, characterized in that said force-feeding means comprises an injector, which is fed by a high-pressure pump and supplies the blade wheel with a mixture of the entraining liquid and the powders.
3. Apparatus according to claim 1, characterized in that said guide ring surrounding the blade wheel is carried by a tube which supplies said substances into said suction zone.