Patent Application
20150085599
The present teachings relate to the field of fluid manufacture and, more particularly, to a method and system for mixing a fluid, for example in a continuous mixing system.
In industry, batch processes may be used to form a desired quantity of a material such as a fluid. However, it is typically difficult to control and minimize batch-to-batch variations. Once quality standards for a particular batch are not met, the entire batch is often rejected and scrapped prior to completion of the batch to prevent further waste of raw materials.
In many batch processes, mixing of a fluid may be a critical process that determines an overall performance of the completed material. For example, in applications where small-sized particles are produced, achieving the small scale and uniform distribution of the particles is determined by the mixing process. Present mixing methods and systems may provide less than uniform mixing efficiency across an entire mixing zone. Mixing may be localized at a central mixing point, for example where an impeller tip for agitation of the fluid is located. Mixing efficiency may decay with increasing distances of the fluid from the impeller tip. Dead spots or shallow spots with inefficient mixing resulting from, for example, fluid turbulence may be distributed along edges of a shaft to which the impeller is mounted. Additionally, a curved vessel or container may result in insufficient mixing.
Other mixing systems and methods may generate more complex setups and have other undesirable characteristics, such as an increased number of mechanical parts that must be serviced and repaired. In another type of system, acoustic techniques have been employed in an attempt to avoid inefficient mixing. An acoustic mixing system may include a non-contact technique to provide micro scale mixing within a micro zone of about 50 μm in a closed vessel. However, generating an acoustic wave relies on mechanical resonance as controlled by engineered plates, eccentric weights, and springs. Particular care and protection of the mechanism to generate mechanical resonance is typically used as small turbulence may damage the system. Therefore, the overall service life of an acoustic system is limited to the effective lifetime of the mechanical components. Thus, such systems are not free of mechanical maintenance. Further, acoustic energy decays at increasing distances of the fluid away from the acoustic wave source.
Though batch processing is a common manufacturing technique that is sufficient for many technologies, it can be wasteful and may complicate future project planning. Continuous processing of a material may be practiced, depending on the industry. See, for example, published US Pub. 2011/0015320 and U.S. Pat. No. 8,168,699, each of which is incorporated herein by reference in its entirety. In continuous processing (i.e., continuous flow process or continuous production), processing of dry or fluid material occurs continuously rather than in batch processing. Constant efforts to prompt new and facile process with compact system design and effective energy saving would be beneficial for process maintenance, lowering production costs, and enhanced process robustness.
Thus, there is a need for a new and improved mixing method and system that overcomes various problems that may be encountered with some conventional systems.
The following presents a simplified summary in order to provide a basic understanding of some aspects of one or more embodiments of the present teachings. This summary is not an extensive overview, nor is it intended to identify key or critical elements of the present teachings, nor to delineate the scope of the disclosure. Rather, its primary purpose is merely to present one or more concepts in simplified form as a prelude to the detailed description presented later.
In an embodiment of the present teachings, a system for mixing a fluid may include a first electromagnet phase and a second electromagnet phase, a receptacle for receiving a fluid to be mixed, wherein the receptacle is interposed between the first electromagnet phase and the second electromagnet phase, and a controller configured to activate the first electromagnet phase out of sync with the second electromagnet phase.
In another embodiment of the present teachings, a method for continuous mixing of a fluid may include pumping a fluid to be mixed into a mixing receptacle, introducing a plurality of magnetic particles into the fluid to be mixed, activating a first electromagnet phase, and activating a second electromagnet phase out of sync with the activation of the first electromagnet phase as the fluid to be mixed and the magnetic particles are within the mixing receptacle, thereby altering a travel path of the plurality of magnetic particles within the fluid to be mixed, wherein the mixing receptacle is interposed between the first electromagnet phase and the second electromagnet phase.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present teachings and together with the description, serve to explain the principles of the disclosure. In the figures:
It should be noted that some details of the FIGS. have been simplified and are drawn to facilitate understanding of the present teachings rather than to maintain strict structural accuracy, detail, and scale.
Reference will now be made in detail to exemplary embodiments of the present teachings, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
The disclosed embodiments relate generally to a method and system for magnetic actuated mixing which use magnetic particles and electromagnetic field to facilitate the mixing. The disclosed embodiments may be used in many different applications, including for example, preparing toners, inks, wax, pigment dispersions, paints, photoreceptor materials, pharmaceuticals, and the like.
In an embodiment of the present teachings, a continuous magnetic mixing apparatus and process can be used during the manufacture of a fluid such as a solid powder or liquid material. Various geometric designs of the mixing zone are contemplated. As an embodiment may use micro size magnetic particles for mixing, the embodiment does not require an external mixer and thus the mixing zone may be designed with a desired shape to enhance production or mixing. A varying magnetic field may be provided by one or more electromagnets. The mixing zone may include a horizontal flowing direction, a vertical flowing direction, or a flowing direction that is between horizontal and vertical. An embodiment may allow for the increase of reactant loading in a compact layout, thus enhancing heat transfer effectiveness, reducing manufacturing cost, alleviating difficulty on machining process, and providing a system that is accessible and easily maintained.
An exemplary mixing zone 11 of a mixing system, apparatus, or structure 10 and process in accordance with an embodiment of the present teachings is depicted in the cross section of
During a continuous mixing process, a fluid 18 to be mixed is injected or otherwise dispensed through a tube inlet 20 into a hollow center 22 of the mixing tube 12. In an embodiment, a plurality of magnetic particles 24 may be mixed into the fluid 18 prior to injection into the mixing tube 12. In another embodiment, the mixing tube 12 may include a magnetic particle inlet 26 through which magnetic particles 24 are injected into the fluid 18 as the fluid 18 is injected into the mixing tube 12.
In an embodiment, the magnetic particles may be micro sized or nano sized. For example, the magnetic particles may be between about 10 nanometers (nm) and about 10 millimeters (mm), or between about 200 nm and about 5 mm, or between about 1000 nm and about 1 mm. Further, the magnetic particles 24 may include, for example, iron (e.g., carbonyl iron), cobalt, nickel, and mixtures or alloys of these metals. Additionally, to reduce chemical reactivity of the magnetic particles with the fluid 18, each magnetic particle may be encapsulated within a chemically inert material such as a polymer. A diameter of the hollow center 22 of the mixing tube 12 may be determined by the desired flow rate of the fluid 18, a viscosity of the fluid 18, and the diameter of the plurality of magnetic particles 24. In general, the diameter of the hollow center 22 may be, for example, between about 10 times and about 100 million times the average diameter of the plurality of magnetic particles 24, or between about 100 times and about 1 million times the average diameter of the plurality of magnetic particles 24.
As the fluid 18 and magnetic particles 24 flow through the mixing tube 12, each electromagnet phase 14, 16 is pulsed out of phase (i.e., out of sync) with the other electromagnet phase(s) to form a varying magnetic field 28 that drives the magnetic particles 24 to move through the fluid 18. Movement of the magnetic particles 24 through the fluid 18 generates turbulence within the fluid 18, thereby mixing the components of the fluid 18. The frequency and amplitude of the electromagnet phase pulses may be determined in part by the viscosity of the fluid 18 and the size and shape of the magnetic particles 24. In a two-electromagnet phase embodiment, the two electromagnet phases 14, 16 may be activated out of sync, for example 180° out of sync, so that the magnetic particles 24 pulse back and forth within the mixing tube 12. In an embodiment, an axis of each electromagnet phase 14, 16 is parallel with an axis of the mixing tube 12, such that the mixing tube 12 is interposed between the two electromagnet phases 14, 16.
To further enhance mixing or to extend the time the fluid remains in the mixing zone 11 (i.e., the fluid residence time), the mixing tube 12 may include various shapes such as the coil shape depicted in
Once the fluid travels through the mixing zone 11 of
The
Thus, an arrangement of the mixing tube 12 and actuation of the electromagnet phases 42A-42G by the controller 46 may be designed to provide efficient mixing of the fluid 18 within the mixing tube 12 within a mixing zone 11 that is compact. For example, in an embodiment, the mixing tube 12 may coil in a first direction (for example clockwise or counterclockwise) from the bottom to the top. The fluid 18 may be dispensed into the mixing tube 12 through the inlet 20 at the bottom of the mixing tube 12 and mixed within the mixing tube 12 using the magnetic particles 24. After mixing, the fluid 18 exits through the mixing tube outlet 30.
In an embodiment, the controller 46 may activate each electromagnet phase 42A-42G successively in a second direction that is opposite to the first direction (for example counterclockwise or clockwise) such that the magnetic particles 24 resist the flow of the fluid 18 from the inlet 20 to the mixing tube outlet 30, thus providing a higher turbulence within the fluid for effective mixing of fluid 18 components within the mixing tube 12. Further, the controller 46 may vary the direction of the electromagnet phase activation from counterclockwise to clockwise during the mixing process to further increase turbulence. Various other magnetic particle 24 travel patterns and mixing tube arrangements are contemplated.
Thus, an embodiment of the present teachings may include a continuous magnetic mixing process and structure that has minimal geometric limitations on the size and shape of the mixing zone 11. The apparatus and process does not require an external mixer such as an impeller. The mixing zone 11 as depicted in
The continuous mixing process and structure may be used during the manufacture of various materials such as during the preparation of printer and other toners, inks, wax, pigment dispersions, paints such as latex paints, photoreceptor materials, pharmaceuticals, and the like.
It will be understood that the embodiments depicted in the FIGS. are generalized schematic illustrations and that other components may be added or existing components may be removed or modified.
Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the present teachings are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Moreover, all ranges disclosed herein are to be understood to encompass any and all sub-ranges subsumed therein. For example, a range of “less than 10” can include any and all sub-ranges between (and including) the minimum value of zero and the maximum value of 10, that is, any and all sub-ranges having a minimum value of equal to or greater than zero and a maximum value of equal to or less than 10, e.g., 1 to 5. In certain cases, the numerical values as stated for the parameter can take on negative values. In this case, the example value of range stated as “less than 10” can assume negative values, e.g. −1, −2, −3, −10, −20, −30, etc.
While the present teachings have been illustrated with respect to one or more implementations, alterations and/or modifications can be made to the illustrated examples without departing from the spirit and scope of the appended claims. For example, it will be appreciated that while the process is described as a series of acts or events, the present teachings are not limited by the ordering of such acts or events. Some acts may occur in different orders and/or concurrently with other acts or events apart from those described herein. Also, not all process stages may be required to implement a methodology in accordance with one or more aspects or embodiments of the present teachings. It will be appreciated that structural components and/or processing stages can be added or existing structural components and/or processing stages can be removed or modified. Further, one or more of the acts depicted herein may be carried out in one or more separate acts and/or phases. Furthermore, to the extent that the terms “including,” “includes,” “having,” “has,” “with,” or variants thereof are used in either the detailed description and the claims, such terms are intended to be inclusive in a manner similar to the term “comprising.” The term “at least one of” is used to mean one or more of the listed items can be selected. Further, in the discussion and claims herein, the term “on” used with respect to two materials, one “on” the other, means at least some contact between the materials, while “over” means the materials are in proximity, but possibly with one or more additional intervening materials such that contact is possible but not required. Neither “on” nor “over” implies any directionality as used herein. The term “conformal” describes a coating material in which angles of the underlying material are preserved by the conformal material. The term “about” indicates that the value listed may be somewhat altered, as long as the alteration does not result in nonconformance of the process or structure to the illustrated embodiment. Finally, “exemplary” indicates the description is used as an example, rather than implying that it is an ideal. Other embodiments of the present teachings will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the present teachings being indicated by the following claims.
Terms of relative position as used in this application are defined based on a plane parallel to the conventional plane or working surface of a workpiece, regardless of the orientation of the workpiece. The term “horizontal” or “lateral” as used in this application is defined as a plane parallel to the conventional plane or working surface of a workpiece, regardless of the orientation of the workpiece. The term “vertical” refers to a direction perpendicular to the horizontal. Terms such as “on,” “side” (as in “sidewall”), “higher,” “lower,” “over,” “top,” and “under” are defined with respect to the conventional plane or working surface being on the top surface of the workpiece, regardless of the orientation of the workpiece.
