Patent Application
20060187744
The present invention relates to an apparatus for mixing fluid.
There are at present several types of mixing attachments used for mixing fluid such as paint. Typically, these attachments include means for attachment to a power tool such as a drill or other tool that causes the mixing attachment to rotate rapidly while immersed in the fluid to be mixed. The fluid is usually contained in a container. These attachments will also usually include at their distal end, i.e. the end of the attachment away from that which attaches to the power tool, lateral blades, cylinders, or other such members that push the fluid while the attachment rotates, thereby assisting in the mixing process.
Such existing mixing attachments are deficient in several respects. First, these attachments tend to be inefficient in that, in order to mix the fluid, they primarily rely upon the centrifugal forces caused by the rotational motion imparted to the fluid. Unfortunately, such centrifugal forces tend to merely push the fluid to the outer boundaries of the container it is in, and the resulting turbulence mixes the fluid rather slowly so that a great deal of time is required to thoroughly mix the fluid. Second, these attachments are relatively ineffective at drawing fluid upwards from the bottom of the container, resulting in a portion of the fluid in the container not being mixed thoroughly. Finally, these mixing attachments often not effective at mixing viscous fluids such as concrete because the attachments lack the sufficient capacity to deliver enough power to mix such fluids.
What is desired then, is an improved mixing apparatus capable of mixing fluid in a shorter period of time, capable of drawing fluid upwards from the bottom of a container, and capable of mixing relatively viscous fluids.
The present inventor realized that, to better mix the fluid 42 in the container 40, a mixing attachment should impart a folding motion to the fluid as generally indicated by the arrows in
It should be understood that, although not quite as effective, a folding motion the reverse of what was just described would also mix fluid more efficiently than existing mixing attachments. That is to say, if the attachment were to impart upward fluid movement proximate the central vertical axis of said container 40, downward fluid movement proximate the periphery of the container 40, inward fluid movement proximate the lower boundary of the container 40, and outward fluid movement proximate the surface of the fluid 42, the fluid would be also mixed much more rapidly and much more thoroughly.
Referring to
As may be seen from this figure, as the apparatus 10 is rotated in a clockwise direction, the vane 26 of the first blade will pull fluid inward towards the longitudinal axis 18 of the shaft while the vane 26 of the second blade 22 will push fluid outward toward the periphery of the container 40 holding the fluid 42. Combined, these two vanes tend to form a vortex 44 (shown in
Preferably, the vanes 24 and 26 are tilted at an angle 28 with respect to the horizontal or vertical axes, respectively of between 5 and 30 degrees. If the angle 28 is less than 5 degrees, the resulting vortex is too weak to produce the desired folding motion. If the angle 28 is greater than 30 degrees, the force imparted to the vanes, and hence the apparatus 10, becomes difficult to control manually. Through experimentation, the inventor has discovered that an angle 28 between 10 and 20 degrees is an ideal compromise between mixing strength and manageability. In the preferred embodiment herein described, the angle 28 is 15 degrees.
As shown in
It should be understood that the description of the fluid motion resulting from clockwise and counterclockwise rotation, respectively, of the apparatus 10 is a result of an arbitrary design choice and may easily be interchanged simply by reversing the tilt of each vane.
It should also be understood that the described mixing apparatus 10 is useful in mixing fluids not contained within a container. For example, it may be desired to place material in a body of water, like a lake, and use the disclosed apparatus 10 to disperse or mix the material. In that context, the foregoing references to the boundaries of the container 40 are not essential to the invention described in this specification.
The terms and expressions that have been employed in the forgoing specification are used therein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalence of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims that follow.
