Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
  • B01F35/71—Feed mechanisms
  • B01F35/714—Feed mechanisms for feeding predetermined amounts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F29/00—Mixers with rotating receptacles
  • B01F29/20—Mixers with rotating receptacles with receptacles rotating about an axis at an angle to their longitudinal axis
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F29/00—Mixers with rotating receptacles
  • B01F29/30—Mixing the contents of individual packages or containers, e.g. by rotating tins or bottles
  • B01F29/31—Mixing the contents of individual packages or containers, e.g. by rotating tins or bottles the containers being supported by driving means, e.g. by rotating rollers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F29/00—Mixers with rotating receptacles
  • B01F29/30—Mixing the contents of individual packages or containers, e.g. by rotating tins or bottles
  • B01F29/32—Containers specially adapted for coupling to rotating frames or the like; Coupling means therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F29/00—Mixers with rotating receptacles
  • B01F29/40—Parts or components, e.g. receptacles, feeding or discharging means
  • B01F29/401—Receptacles, e.g. provided with liners
  • B01F29/4011—Receptacles, e.g. provided with liners characterised by the shape or cross-section of the receptacle, e.g. of Y-, Z -, S -, or X shape
  • B01F29/40118—V or W shapes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F29/00—Mixers with rotating receptacles
  • B01F29/40—Parts or components, e.g. receptacles, feeding or discharging means
  • B01F29/401—Receptacles, e.g. provided with liners
  • B01F29/402—Receptacles, e.g. provided with liners characterised by the relative disposition or configuration of the interior of the receptacles
  • B01F29/4021—Multi-compartment receptacles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F29/00—Mixers with rotating receptacles
  • B01F29/40—Parts or components, e.g. receptacles, feeding or discharging means
  • B01F29/403—Disposition of the rotor axis
  • B01F29/4034—Disposition of the rotor axis variable, e.g. tiltable during the operation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F29/00—Mixers with rotating receptacles
  • B01F29/40—Parts or components, e.g. receptacles, feeding or discharging means
  • B01F29/403—Disposition of the rotor axis
  • B01F29/4035—Disposition of the rotor axis with a receptacle rotating around two or more axes
  • B01F29/40353—Disposition of the rotor axis with a receptacle rotating around two or more axes being perpendicular axes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F29/00—Mixers with rotating receptacles
  • B01F29/60—Mixers with rotating receptacles rotating about a horizontal or inclined axis, e.g. drum mixers
  • B01F29/64—Mixers with rotating receptacles rotating about a horizontal or inclined axis, e.g. drum mixers with stirring devices moving in relation to the receptacle, e.g. rotating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F31/00—Mixers with shaking, oscillating, or vibrating mechanisms
  • B01F31/50—Mixers with shaking, oscillating, or vibrating mechanisms with a receptacle submitted to a combination of movements, i.e. at least one vibratory or oscillatory movement
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F33/00—Other mixers; Mixing plants; Combinations of mixers
  • B01F33/50—Movable or transportable mixing devices or plants
  • B01F33/502—Vehicle-mounted mixing devices
  • B01F33/5023—Vehicle-mounted mixing devices the vehicle being a trailer which is hand moved or coupled to self-propelling vehicles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
  • B01F35/71—Feed mechanisms
  • B01F35/717—Feed mechanisms characterised by the means for feeding the components to the mixer
  • B01F35/7174—Feed mechanisms characterised by the means for feeding the components to the mixer using pistons, plungers or syringes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F33/00—Other mixers; Mixing plants; Combinations of mixers
  • B01F33/50—Movable or transportable mixing devices or plants
  • B01F33/502—Vehicle-mounted mixing devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
  • B01F35/20—Measuring; Control or regulation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
  • B01F35/71—Feed mechanisms

Definitions

• V-blenders are widely used in many industries requiring blending, granulating, and drying of powders.
• V-blenders also referred to as twin shell blenders
• the mixing vessel is typically connected to a rotating shaft which causes a tumbling motion of the powders within the vessel or shell.
• the rotating shaft is usually parallel to the ground and pe ⁇ endicular to the plane of symmetry of the blender.
• the V-blender may be fitted with an intensifier bar which rotates as much as 100 times the speed of the shell.
• the intensifier bar is typically positioned along the axis of rotation of the shell.
• V-blenders are used both in the laboratory as small-scale product development units and in manufacturing as large-scale production units.
• V-blenders use constant speed tumbling motion to mix powders, e.g., V-blenders manufactured by Paul O. Abbe Inc. (Little Falls, NJ), Bowers Process Equipment Inc. (Stafford, ON), Gemco (Middlesex, NJ), Jaygo, Inc. (Mahwah, NJ), Lowe Industries Inc., (Cadiz, KY), Patterson Industries Ltd. (Scarborough, ON), and Patterson-Kelley (East Stroudsburg, PA).
• a mixture is considered well mixed when the standard deviation of samples taken from the mixture are equal to the standard deviation of a random mixture or fall within an acceptable variation for a particular application.
• Gray found that a mixture of sand and ilmenite continued to improve its mixedness even after 1000 revolutions at 24 ⁇ m. (Gray, J., "Solids Mixing Equipment", Chem. Eng. Progr., 53, (1957), 25). Wiedenbaum et al. found that a random mixture of same- sized sand and salt particles was not obtained even after 5000 revolutions at 24 ⁇ m.
• V-blenders with (1 ) legs of different lengths (P-K Cross- FlowTM Blender, Patterson Kelley, East Strousburg, PA), (2) the rotating shaft mounted parallel to the ground but offset from the orthogonal to the plane of symmetry of the blender (Challenger TM OffsetTM V-Blender, Lowe Industries, Inc., Cadiz, KY), and (3) rotating blades mounted to rotate in the plane of the 'V of the blender (Chopper blades, Lowe Industries, Inc., Cadiz, KY)
• An improved mixing method consisting of a V-blender wherein mixing is enhanced by a controlled axial flow perturbation.
• perturbations are introduced by rocking the device with respect to its axis. Such perturbations produce a convective axial flow, resulting in large accelerations of the mixing process. It is claimed that similar enhancements could also be obtained by using other means to perturb the flow of particles.
• the invention relates to a method for enhancing the mixing of solids using a V-blender and a controlled axial flow perturbation. Also within the scope of this application is the V-blender apparatus capable of introducing a controlled axial flow perturbation to enhance the mixing of solids.
• V-blender twin shell blender
• Vessel loading procedure (a) plunger inserted, (b) red beads are added to one leg, (c) green beads are added to second leg, and (d) vessel turned to upright position.
• Schematic of infiltration apparatus including fluid reservoir, pump, and solution delivery system.
• Figure 9 Interior mixing patterns of 66 micron particles mixed at 16 ⁇ m for 10 minutes with (a) no rocking and (b) a rocking ratio of 3.14 revolutions per rocking cycle where the rocking motion is at +/-10 degrees.
• Figure 10 Schematic of the image analysis equipment setup.
• the invention relates to a method for mixing solids in a V- blender comprising controlled axial flow perturbations.
• controlled axial flow perturbation is selected from the group consisting of: (a) rotation of the shell with a rocking motion,
• the method wherein the controlled axial flow perturbation is introduced by combined time-dependent rotation speed of the shell with rocking motion, and is defined by a speed of rotation of about 0 to about 50 ⁇ m, a frequency of rotation rate changes per revolution of about 0 to about 1 , a rocking angle of about 0° to about +10 degrees or - 10 degrees, and a rock to roll frequency of about 0 to about 31.4.
• the method wherein the controlled axial flow perturbation is introduced by combined time -dependent rotation direction of the shell with a rocking motion, and is defined by a speed of rotation of about 0 to about 50 ⁇ m, and a frequency of rotation direction changes per revolution of about 0 to about 1 , rocking angle of about 0° to about +10 degrees or -10 degrees, and a rock to roll frequency of about 0 to about 31.4.
• the method wherein the controlled axial flow perturbation is introduced by combined rotation of the shell with ribbon rotation, and is defined by a speed of the shell of about 0 to about 50 ⁇ and a ribbon speed of about 0 to about 3600 ⁇ m.
• the method wherein the controlled axial flow perturbation is introduced by combined rotation of the shell with time -dependent ribbon rotation speed, and is defined by a speed of the shell of about 0 to about 50 ⁇ m, a ribbon speed of about 0 to about 3600 ⁇ m and frequency of ribbon rotation direction changes per shell revolution of about 0 to about 1.
• the ribbon rotation is defined as the rotation of a ribbon which is attached to an intensifier bar of a V-blender.
• Red and blue 600 ⁇ glass beads (Jaygo Inc., Union, NJ) were used in the direct visualization experiments.
• the total loading for each experiment was 50% of the total vessel volume.
• the vessels were loaded axially, with one color being loaded into each shell. This was done one color at a time.
• First a plunger was inserted into one end of the twin shell (Fig. 3a).
• a measured amount of red beads was added into the other end of the shell (Fig. 3b) and the plunger depth was then adjusted until the level of beads was at the centerline of the twin shell.
• a measured amount of green beads was then carefully added on top of the layer of red beads (Fig. 3c) so that the red/green interface between the beads was maintained along the centerline of the twin shell.
• the vessel was carefully turned upright (Fig 3d) and the ends of the twin shell were closed with caps.
• a photograph of the initial condition for an experiment is shown in Fig. 4.
• the second type of experiment was designed to facilitate examination of the structure of the mixture throughout the entire volume of the powder bed.
• the structure of the mixture was preserved by infiltrating the voids between particles with a polymer solution, which was allowed to cross-link, yielding a solidified monolith.
• This monolith was subsequently sliced to reveal the internal structure of the mixture.
• These solidification experiments were carried out in custom-made aluminum twin shell vessels (American Aluminum Co., Mountainside, NJ) that had identical dimensions and were loaded in the same manner as the Plexiglas V- blender vessels.
• one of the rollers in the computer-controlled drive was replaced by a shaft with a mounting extension.
• the twin shell vessels were housed inside a frame attached to the mounting extension (Fig. 5). Red and green 66 ⁇ glass beads (Potters Industries Inc., Parsippany NJ) were used in the solidification/slicing experiments. After the mixing run was completed, the twin shell vessel was carefully removed from the mixing apparatus without disturbing the mixture. It was then placed into an infiltration apparatus where it was held in a secure horizontal position.
• the infiltration apparatus shown in Fig. 6, consisted of a fluid reservoir, a pump, and tubing connected to a nozzle.
• the infiltration medium used was a commercially available mixture of SD alcohol 40, water, octylacrylamide, acrylates and butylaminometh- acrylate copolymer (Rave®, Chesebrough Ponds USA Co., Greenwich, CT).
• the medium was pumped slowly onto the mixture to avoid trapping air in the system.
• the nozzle was placed at the centerline of the vessel near the wall allowing the medium to flow gently onto the powder bed, which pushed the air out slowly through the open ends of the vessel. Repeated experiments have shown that the infiltration process does not cause any disturbances to the mixture.
• the embedded mixtures were allowed to dry for a period of about two weeks.
• the solidified structures were removed from the vessels and sliced using a bandsaw. First the mixing vessel was sliced along the centerline while the vessel still contained the mixture. The two shells were then cut along the top surface of the solidified beads. After briefly heating the shells, the solidified structures were easily detached from the shell walls and removed from the vessels. The structures were then sliced in half inch intervals along the axis of rotation as shown in Fig. 7. Each experiment resulted in about fourteen sections.
• FIG. 8a is the state of the mixture after five minutes of pure rotation at 16 ⁇ m.
• Fig. 8b shows that only a minimal amount of mixing has occurred.
• Fig. 8c shows the state of the mixture after 5 minutes of mixing at 16 ⁇ m with rocking.
• a ratio of 3.14 revolutions per rocking cycle was used in this experiment. In this case the beads appear to be very well mixed.
• FIG. 9a is a photograph of an experiment carried out with a rotation rate of 16 ⁇ m for a total mixing time of 10 minutes with no rocking. As can be seen in the photograph, the composition of each slice along the axis of rotation varies greatly from one end of the structure to the other.
• Figure 9b is a photograph of an experiment carried out using rocking. The experiment corresponds to a rotation rate of 16 ⁇ m, the same total mixing time as before (10 minutes) and a ratio of 3.14 revolutions per rocking cycle. In this case the composition is essentially the same for all slices.
• FIG. 10 depicts the image analysis equipment setup.
• a 6510 CCD monochrome camera (Cohu Inc., San Diego, CA) with a Computer 55 mm F/2.8 telecentric video lens (Edmund Scientific Company, Barrington, NJ) is mounted vertically above the image. Sufficiently uniform illumination of the field of view is attained by a fiber optic ring light (Volpi Manufacturing USA, Auburn, NY).
• This light source is supplied by a 150- watt halogen bulb housed in an Intralux 6000-1 controller (Volpi Manufacturing USA, Auburn, NY).
• a sha ⁇ cut filter (R-60, Newport Co ⁇ oration, Irvine, CA) is used to attenuate the shorter wavelengths (690 NM or less) while transmitting the longer wavelengths.
• Use of such a filter maximizes gray scale contrast of the red and green components.
• the red component becomes the brightest; the green component, the darkest.
• Each slice is scanned with the aid of a programmable xy-table (Unidex Aerotech Inc., Pittsburgh, PA) operated remotely by a computer.
• the video signal is digitally displayed as an 8 bit image (256 gray levels) on an RS-170 picture monitor (Sony Trinitron Model No. PVM-1342C, Sony Co ⁇ ., Tokyo, Japan).
• the output signal from the monitor is sent to an MV20 image processing board (Datacube Inc., Danvers, MA) where the signal is converted from analog to digital.
• the image is displayed as a gray-scale image on a Sun Workstation (Sun, Mountain View, CA), where an image processing software program (recently developed at the Center for Computer Aids for Industrial Productivity, Rutgers University, Piscataway, NJ) handles the video signal, data retrieval, and storage.
• FIG. 1 1 shows a sketch of a slice with these field subdivisions.
• Each field contains approximately 10,000 particles and is digitized into 480 x 512 pixels, with each pixel possessing a gray level on a scale from 0 to 255.
• each field of view is further subdivided into regularly spaced regions, hereon called "patches".
• the local composition is measured for each of these small patches by computing the mean gray level intensity of the pixels in the patch.
• the patches become the smallest area evaluated in the experiments. Therefore, the patch size determines the scale of examination in the mixing analysis.
• Statistics such as the mean, mode, and standard deviation are computed for each patch. These data and the raw pixel values of the field image are written in separate files for post-processing and analysis. After the data is collected for a field, the program executes a command to move the xy-table to the next field address. This sequence of data collection and move commands is repeated until the entire slice is scanned.
• the overall probability density functions for both mixtures are shown in Figure 15.
• the distribution for the pure rotation case is bimodal, while the case with rocking has a normal distribution. While the means of both mixtures are essentially the same (52% red), the relative standard deviation of the case with pure rotation is 23.9% compared to 6.9% for the case with rocking.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Physics & Mathematics (AREA)
• Geometry (AREA)
• Medicines Containing Material From Animals Or Micro-Organisms (AREA)
• Mixers Of The Rotary Stirring Type (AREA)

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• 1996
  • 1996-10-25 CA CA002236009A patent/CA2236009A1/en not_active Abandoned
  • 1996-10-25 EP EP96936994A patent/EP0865310A4/de not_active Withdrawn
  • 1996-10-25 JP JP9517434A patent/JPH11514569A/ja not_active Withdrawn
  • 1996-10-25 WO PCT/US1996/017178 patent/WO1997016240A1/en not_active Application Discontinuation
  • 1996-10-25 AU AU74768/96A patent/AU717407B2/en not_active Ceased

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