MFP Mixer

This mixer's unique design provides transverse mixing action. Blending occurs rapidly, clumps are broken up, and a shorter mix time is needed to achieve accepted coefficient of variation. The Trans-Mix also performs well with liquid ingredients. There are hundreds of these stationary mixers operating in the field and providing their owners with a quality mix.

The Transverse Mixer, available in 100 and 175 cubic feet, differs from other vertical mixers in that it contains a large diameter tapered primary mixing auger and a "J" shaped hopper on the side of the frustum at the bottom. This "J" hopper intersects the main vertical tank causing a nonsymmetrically enlarged volume at the bottom.

This unique design dramatically improves mix quality over traditional vertical mixers. Instead of a mix time of 15 minutes, with the poor mix quality common with traditional vertical mixers, the Trans-Mix can obtain an accurate mix in as few as three minutes with a coefficient of variation at or better than most ribbon horizontal mixers.

The vertical two-stage screw functions at the center of the vertical tank. This is similar to other high efficiency vertical mixers such as on the SFM (formerly marketed by Weigh-Tronix), where the large diameter screw prevents excessive top center flow which causes particle size separation. In addition, the nonsymmetry at the bottom of the Transverse Mixer creates a nonuniform vertical flow, thus breaking up stratification which is typical in many other vertical mixers. These features in themselves have proven to provide a very complete mix in the well-proven SFM, but the Transverse Mixer does an even better job by amplifying the effects in its vertical mixing screw. The large diameter screw is three times longer and holds a much larger volume of feed. The transverse horizontal auger screws and kicker force feed the vertical screw and provide a 50 percent larger flow volume to the bottom mixer stage.

A tube on the top stage of the vertical screw (100 cubic foot mixer) provides greater usable tank capacity and prevents particle separation from low velocity surface inclines. This tube is only 14 inches long (or two flight pitches) near the top so that the remaining second-stage screw is uncovered and uses the feed surrounding it as a virtual tube. This causes a reactive force against the surrounding feed which in turn causes some added vertical flow. This also causes the feed to rotate around the second-stage screw at a slower rate. This allows the level in the tank to remain more uniform even though the "J" hopper with its two opposing horizontal screws is creating a greater flow in one side of the tank. This rotation also causes stratified layers to blend in conjunction with the nonuniform vertical return flow rates.

Feed which enters the bottom mixing stage cycles at around 30 times per minute in a zone where three screws move the feed seven inches per revolution at a 400 revolution per minute rate. This causes blending to occur very rapidly. Clumps which would tend to stay intact in other mixers, such as some horizontal types, are completely broken up and distributed within approximately 7 cubic feet of blended feed. Flow rates in this stage vary as does the path length, thereby, assisting in particle distribution.

The bottom stage cycles a volume of approximately 7 cubic feet and the remaining volume is in the top stage. If only 300 pounds of 43 pounds per cubic foot of feed is introduced in the mixer, it will be cycled at nearly 30 times per minute in the bottom stage. This will happen in a totally nonsymmetric mix pattern, resulting in a mix of better than10 percent CV in 4 cycles or 8 seconds. At 600 pounds, the top stage would contain 300 pounds cycling at nearly 4 times per minute. A complete mix would be achieved in 2 cycles or 30 seconds. When 2000 pounds are in the mixer, 1700 pounds are in the top stage cycling at 1.5 minutes per cycle. A complete mix can be achieved in 2 cycles, or 3 minutes.