The present invention relates generally to a device and method of cavitational mixing. However, it finds particular application in both mixing and pumping applications and will be described with particular reference thereto.
Up to the present time, it is well known that there are many chemical reactions that essentially alter the speed and yield of finished products under the influence of ultrasonic oscillation.
There also exists a great quantity of chemical reactions and mixing that may only proceed under the influence of ultrasonic oscillation. Similar reactions may be accomplished in aqueous as well as non-aqueous, liquid-based media. The main requirement for the realization of similar reactions is the imposition of ultrasonic oscillations on the liquid medium. All of these chemical reactions relate to the class of sonochemical reactions. As determined through many years of investigation and numerous research studies (Timothy J. Mason, “Advances in Sonochemistry”, Volume 3. 1993. 292 pp., JAI Press Inc.), the sources of initiation of sonochemical reactions appear as cavitation bubbles which arise in liquid-based media during diffusion within by ultrasonic oscillations.
During the collapse of the cavitation bubbles, very high localized pressures and temperatures are achieved. According to some estimations the temperature within the bubbles attains a magnitude in the order of 5000° C. and pressure of approximately 500 kg/cm2 (K. S. Suslick, Science, Vol. 247, Mar. 23, 1990, pgs. 1439-1445). These high temperatures and pressures stimulate the progress of various chemical reactions such as in the gaseous phase within the bubble as well as in the gaseous phase on the surface of the bubble.
Common for all sonochemical reactions and processes is that, for the creation of cavitation bubbles in a liquid-based medium, the principle of application of ultrasonic oscillations on the liquid-based medium is used. The basic equipment which is used in sonochemistry appear as ultrasonic devices of various designs.
This method of conducting sonochemical reactions is sufficiently effective for processing small volumes of liquids and has found its chief application on the level of laboratory research. Transitioning to large scale volumes, however, which are used in industry, is significantly difficult and even at times impossible. This is associated with the problems which arise during the scaling up of cavitation that is produced with the aid of ultrasonic oscillations.
It is possible to avoid these shortcomings, however, by producing the quality of the initiator of sonochemical reactions, cavitation bubbles, through the course of hydrodynamics. An example of using hydrodynamic cavitation for conducting sonochemical reactions is presented in the work of: Pandit A. B., Moholkar V. S., “Harness Cavitation to Improve Processing,” Chemical Engineering Progress, July 1996, pgs. 57-69.
However, the aforementioned example method of realizing sonochemical reactions with the aid of hydrodynamic cavitation is not effective. As noted by the authors themselves, one of the problems they uncovered was the ineffective utilization of the energy in the hydrodynamic flow. Utilization of non-optimal regimes of hydrodynamic cavitation leads to a decrease in the intensity of sonochemical reactions and increases the degree of heating the medium.
In the present invention, the proposed method of conducting sonochemical reactions and processes, particularly in large scale volumes of liquid-based media, allows the utilization of optimal hydrodynamic cavitation regimes and also reduces the energy consumption for conducting the processes.
The present invention contemplates a new and improved method and apparatus for conducting sonochemical reactions and processes, particularly in large scale volumes of liquid based media, using the optimal hydrodynamic cavitation regimes and reducing the energy consumption for conducting the processes, which is simple in design, effective in use, and overcomes the foregoing difficulties and others while providing better and more advantageous overall results. Specifically, the present invention relates to utilizing cavitation in large scale volumes for both mixing and pumping applications.
The present invention overcomes problems in the prior art and others.
The present invention provides for a mixing device including a body having a base portion and a peripheral wall extending from the base portion and defining an inlet space therebetween. Additionally, the base portion includes at least one inlet port disposed therein that is in fluid communication with the inlet space. The peripheral wall includes an outlet channel disposed therein that is in fluid communication with the inlet space. A cavitation assembly is disposed within the outlet channel. Alternatively, a plurality of cavitation assemblies may be disposed within the outlet channel.
The cavitation assembly may include a baffle body that creates a local constriction between the baffle body and the outlet channel. Alternatively, the cavitation assembly may include at least two baffle bodies connected in series that create at least two local constrictions between the baffle bodies and the outlet channel of each of the baffle bodies.
Further, the present invention may include a shaft, and means for rotating (i.e. motor) the shaft connected coaxial to the base portion of the body opposite the peripheral wall. In this embodiment, the body has a generally cylindrical shape.
In another embodiment, the present invention provides for a device for mixing fluid comprising a body wherein the body includes a base portion and a peripheral wall extending from the base portion and defining an inlet space therebetween. The base portion includes at least one inlet port disposed therein that is in fluid communication with the inlet space. The peripheral wall includes an outlet channel disposed therein that is in fluid communication with the inlet space and a means for creating cavitation disposed within the outlet channel.
The means for creating cavitation may be a baffle body that creates a local constriction between the baffle body and the outlet channel thereby effectuating cavitational mixing downstream from the baffle body. Alternatively, the means for creating cavitation may include at least two baffle bodies connected in series that create at least two local constrictions between the baffle bodies and the outlet channel thereby effectuating cavitational mixing downstream from each of the baffle bodies.
In another embodiment, the present invention provides for a method for mixing a fluid comprising the steps of first providing an agitator head assembly into a volume of fluid, where the agitator head assembly comprises (i) a base portion and a peripheral wall extending from the base portion defining an inlet space therebetween, the base portion includes at least one inlet port disposed therein which is in fluid communication with the inlet space, the peripheral wall includes an outlet channel disposed therein which is in fluid communication with the inlet space; and (ii) a cavitation assembly disposed within the outlet channel. The next step is rotating the agitator head assembly to create centrifugal forces thereby forcing the fluid through the cavitation assembly. Finally, creating cavitation when the fluid passes through the cavitation assembly thereby effectuating mixing of the fluid.
Another embodiment of the present invention provides for a device having pumping and mixing capabilities. This alternate embodiment comprises (i) a housing having an inlet for supplying a liquid and an outlet; (ii) an agitator head assembly having a base portion and a peripheral wall extending from the base portion defining an inlet space therebetween and disposed within the housing. The peripheral wall includes an outlet channel disposed therein that is in fluid communication with the inlet space. The inlet space is in fluid communication with the inlet of the housing, (iii) means for creating cavitation disposed within the outlet channel; and (iv) means for rotating the agitator head assembly within the housing.
In this embodiment the means for creating cavitation may be a baffle body coaxially disposed in the outlet channel to provide a local constriction between the baffle body and the outlet channel. Alternatively, the means for creating cavitation may be a plurality of baffle bodies coaxially disposed in series in the outlet channel to provide a local constriction between the baffle bodies and the outlet channel. The inlet orifice in this embodiment may be disposed perpendicular to said outlet orifice. Additionally, the rotating means may be a motor.
Another embodiment of the present invention provides for a method for mixing and pumping a liquid comprising the steps of (i) providing an agitator head assembly in a housing having an inlet and an outlet, where the agitator head assembly includes a top portion and a peripheral wall extending from said top portion defining an inlet space therebetween wherein the peripheral wall includes an outlet channel disposed therein which is in fluid communication with the inlet space in fluid communication with the inlet of the housing and a means for creating cavitation disposed within the outlet channel; (ii) supplying liquid to the inlet of the housing; (iii) rotating the agitator head assembly to create centrifugal forces in the fluid thereby forcing the substance through the cavitation assembly; and (iv) creating cavitation when the fluid passes through the cavitation assembly thereby effectuating mixing of the fluid resulting in a mixed fluid. In this embodiment, the means for rotating said agitator head assembly creates centrifugal forces to cause the mixed fluid to exit the outlet in the housing thereby effectuating pumping the mixed fluid.
The above aspects and other embodiments, features, and advantages of the present invention are more readily understood from a review of the attached drawings and the accompanying specification and claims.
The invention may take form in various components and arrangements of components. The drawings are only for the purposes of illustrating the preferred and alternate embodiments and are not to be construed as limiting the invention.
Referring to
Continued reference to
Again referencing
In operation, as illustrated in
Upon rotation of the shaft 110, the agitator head assembly 120 is likewise rotated in the corresponding direction of the rotation of the shaft 110. This rotation of the agitator head assembly 120 creates centrifugal forces within the liquid 165 situated in the inlet space 155 as illustrated by the arrows in FIG. 1A. These centrifugal forces cause the liquid 165 to enter the outlet channels 150. Because the outlet channels 150 are in fluid communication with the inlet space 155, the liquid enters the cavitation assembly 160 via the outlet channels 150 as illustrated in FIG. 1A. The cavitational mixing occurs within the cavitation assembly 160 positioned within the outlet channel 150.
Continued reference to
The flow continues through outlet channel 150 and around the second baffle body 260. At the second baffle body 260, the liquid flow passes through the second local constriction 230, where the velocity of the liquid flow increases to a minimum velocity dictated by the physical properties of the liquid thereby forming cavitation bubbles. Again, beyond the second baffle body 260, the cavitation bubbles enter a second increased pressure zone 235 and thereby collapse enhancing the mixing process. The mixed liquid then exits the outlet channel 150 via outlet 220. After passing through the cavitation the mixed liquid is re-circulated into the original volume of the liquid.
This process is continuously repeated as the agitator head assembly 120 is continuously rotated.
In an alternate embodiment as illustrated in
In operation, centrifugal forces cause the liquid to enter the cavitation assembly 160′ in the same manner as described above. The liquid flow, moving along the direction indicated by arrow A flows into the cavitation assembly 160′ and around the baffle body 360. At the baffle body 360, the liquid flow passes through the local constriction 330, where the velocity of the liquid flow increases to a minimum velocity dictated by the physical properties of the liquid. The flow velocity in the local constriction 330 is increased while the pressure is decreased resulting in formation of cavitation cavities or voids in the flow, which on having been disintegrated, form cavitation bubbles defining the structure of the cavitation field. These cavitation bubbles then enter into an increased pressure zone 335 resulting in a reduced flow velocity and collapse. The resulting cavitation effects exert a physio-chemical effect on the mixture of liquid components, thus initiating improved mixing, emulsification, homogenization and dispersion. After passing through the cavitation assembly 160′, the mixed liquid flows to the outlet 320 and is re-circulated into the original volume of the liquid via outlet 320. This process is continuously repeated as the agitator head assembly 120 is continuously rotated.
In alternate embodiments and in order to control and specify the required structure of the cavitation bubbles field, baffle bodies 260, 360, as illustrated in
Referring now to
In the cavitation assembly 160″, baffle 420 is positioned inside outlet channel 150 after inlet 440. Baffle 420 includes transit channel 450 in its own body, which is carried out in the shape of a Venturi tube. This transit channel 450 produces a local constriction of the liquid flow.
In operation, centrifugal forces cause the liquid to enter the cavitation assembly 160″ in the same manner as described above. The liquid flow, moving along in the direction as indicated by arrow A is throttled through the transit channel 450 at a velocity sufficient to generate cavitation thereby producing cavitation bubbles. An increased pressure zone 460 is created thereby producing a cavitation cavern wherein the cavitation bubbles collapse effectuating the mixing process. As described in previous embodiments, these cavitation effects provide improved mixing, emulsification, homogenization and dispersion.
Additionally, the transit channel 450, as illustrated in
With reference to
In another embodiment, the present invention provides for an apparatus 600 that has mixing and pumping capabilities as illustrated in
Referring now to
As illustrated, in this embodiment, the agitator head assembly 620 is positioned inside the pump housing 610 and is connected to the rotating means (not shown) via a drive shaft 630.
Agitator head assembly 620 is pressure fitted and fixed to one end of the drive shaft 630. Although the embodiment utilizes a pressure fitted technique of connecting the agitator head assembly 620 to the drive shaft 630, it is contemplated that additional connecting techniques could be used to fix the agitator head assembly 620 to the drive shaft 630. In other embodiments, the agitator head assembly 620 is pinned, glued, welded, threaded, bolted, riveted or the like to connect the agitator head assembly 620 to the drive shaft 630. The drive shaft 630 is connected to a motor (not shown) which when operated, rotates the drive shaft 630. It is understood that other means of rotating the drive shaft 630 may be implemented including, but not limited to, pulleys, cranks or the like.
Continued reference to
Still referencing
Although the cavitation assembly 160 illustrated in
In alternate embodiments and in order to control and specify the required structure of the cavitation bubbles field, baffle bodies 260, 360, as illustrated in
Additionally, the transit channel 450, as illustrated in
In operation, liquid is first supplied to pump housing 610 via inlet 710 and enters inlet space 775. Upon rotation of the drive shaft 630, the agitator head assembly 620 is likewise rotated in the corresponding direction of the rotation of the drive shaft 630. This rotation creates centrifugal forces within the liquid in inlet space 775 thereby causing the liquid to enter the outlet channels 750. Because the outlet channels 750 are in fluid communication with the inlet space 775, the liquid enters the cavitation assembly 160 via the outlet channels 750 thereby creating cavitation in the same manner as described above thus effectuating mixing of the liquid. In combination with the mixing as described above, apparatus 620 provides for pumping of the liquid wherein the centrifugal forces caused by the rotation of the agitator head assembly 620 forces the mixed liquid to exit the pump housing 610 via outlet 720.
Although the present invention has applications in mixing and pumping, one skilled in the art would appreciate that the present invention may be utilized as a reactor to enhance and expedite chemical reactions.
The invention has been described with reference to the preferred embodiments and selected alternate embodiments. Modifications and alterations will become apparent to persons ordinarily skilled in the art upon reading and understanding the preceding detailed description of the invention. It is intended that the invention be construed as including all such alterations and modifications insofar as they come within the scope of the appended claims or the equivalence thereof.
Number | Name | Date | Kind |
---|---|---|---|
780260 | Beemer | Jan 1905 | A |
865030 | Forbes | Sep 1907 | A |
1338996 | Norcross | May 1920 | A |
1417883 | Beers | May 1922 | A |
2541221 | Edwards | Feb 1951 | A |
2588591 | Thompson | Mar 1952 | A |
2609189 | Derina | Sep 1952 | A |
2626135 | Serner | Jan 1953 | A |
2645464 | Forbes | Jul 1953 | A |
2673075 | Borck | Mar 1954 | A |
2985389 | Willems | May 1961 | A |
3128084 | Castor | Apr 1964 | A |
3273865 | White | Sep 1966 | A |
3414245 | Frazer | Dec 1968 | A |
3486741 | Midgette | Dec 1969 | A |
3690621 | Tamaka et al. | Sep 1972 | A |
3820759 | Hege | Jun 1974 | A |
3953004 | Schmidt et al. | Apr 1976 | A |
3961775 | Markus | Jun 1976 | A |
4021349 | Kaelin | May 1977 | A |
4283357 | Sidery | Aug 1981 | A |
4339206 | Ahs | Jul 1982 | A |
4416548 | Carre et al. | Nov 1983 | A |
4451155 | Weber et al. | May 1984 | A |
5226727 | Reichner | Jul 1993 | A |
5628616 | Lee | May 1997 | A |
6035897 | Kozyuk | Mar 2000 | A |
6132080 | Gurth | Oct 2000 | A |
6168307 | Venans | Jan 2001 | B1 |
6280078 | Lewis | Aug 2001 | B1 |
6312216 | Falcimaigne | Nov 2001 | B1 |
6354729 | Brown | Mar 2002 | B1 |
6616325 | Brown | Sep 2003 | B1 |
Number | Date | Country |
---|---|---|
2308076 | Jun 1997 | GB |
WO 0059617 | Oct 2000 | WO |
Number | Date | Country | |
---|---|---|---|
20040022122 A1 | Feb 2004 | US |