Size Reduction Spotlight - September 09

Roller Mill
The VRM roller mill provides efficient fine grinding of soft to medium-hard materials. Designed for continuous operation, the VRM’s basic concept is based on the combination of a high-quality mill body and highly efficient TC and Alpha classifiers. The mill body is designed with two or three rollers and provides a sharp and very-fine top cutdown to d98<6 µm. The unit is ideal for fine grinding and classification of a wide variety of materials including calcium carbonate, dolomite, talc, bentonite, barites, petroleum, coke, calcium oxide, and gypsum.
Sweco, Florence, KY 800-807-9326 www.sweco.com

Single-Shaft Shredders
The SXS1500, SXS2000, and SXS3000 single-shaft shredders are available with three different rotor types for flexible processing. Each rotor is equipped with square cutters (60 mm) for efficient cutting and is reversible for quick changes. Built rugged for demanding and specialized applications, the SXS series provides reduced heat buildup and degradation and offers an abrasion-resistant rotor for longer life. Dual-motor driven, the SXS provides even horsepower displacement on both ends of the rotor and is available with two-speed ram hydraulics. Second-stage granulation can be easily configured as an option.
Sterling, New Berlin, WI 262-641-8610 www.sterlco.com

Classifier Mills
The CLM series classifier mills are a combination of two stages of closed-circuit grinding and air classification all in one unit. Materials that are difficult to grind, and those that require a finer grind or a narrower particle distribution curve than is practical to produce in a fine grinder, often require the capabilities of these mills. In order to separate, the built-in classifier, which is the part of the grinding rotor designed to handle these difficult-to-grind items, rejects large particles not completely ground in the first stage of grinding. They are reground and then reclassified.
Prater-Sterling, Bolingbrook, IL 630-759-9595 www.prater-sterling.com

Nonattrition Grinder
The Model 1052 Gran-U-Lizer features exclusive material technology for ultrahigh-purity grinding applications. This grinding technology is proven to grind hard, abrasive materials, such as silicon and cadmium telluride, to precise sizes with minimal foreign material contamination. It also delivers high particle uniformity with few fines and adjusts to achieve median sizes from 120 to 5000 µm.
Modern Process Equipment Inc., Chicago, IL 773-254-3929 www.mpechicago.com

Cone Mill
The Kek cone mill can take a wide range of feed material and produce an equally wide range of product, making it ideal for intermediate sizing in both wet and dry granulation processes. The unit provides a gentle low-energy form of size reduction and eliminates traditional milling problems including noise, dust, and heat. The gentle grinding action is capable of control within fine limits while maintaining a close particle size distribution with minimal fines generation. The unit typically grinds from 25 to 250 µm.
Kemutec Powder Technologies, Bristol, PA 215-788-8013 www.kemutec.com

Power Graters
Several alternatives are available when industrial processes require de-lumping, particle sizing, crushing, shredding, and de-agglomeration. This family of power graters processes soft to medium-hard products such as filter cakes, foodstuffs, plastics, and salts in nominal capacities ranging from 2 to 4 tn/hr. All models are available with motor options and low-speed drives for low operating sound levels. Various materials of construction (mild steel, stainless steel, Hastelloy, etc.) and screen sizes are also available to suit the mechanical and chemical elements of the application. Custom designs are available.
S. Howes Inc., Silver Creek, NY 888-255-2611 www.showes.com

Ultrasanitary Mill
The Definer is a versatile, ultrasanitary mill with the processing capabilities of several mills in one. This unit easily reduces a variety of powders and agglomerates to a controlled output particle size. It is designed to meet the special demands of the pharmaceutical, food, dairy, and chemical industries. It is a fully enclosed, dust-tight unit constructed entirely of stainless steel. The machine is easy to clean and can be disassembled and reassembled in a matter of minutes. Its compact body measures 5 in. from inlet to outlet. A straight flow-through product path eliminates the possibility of hangup or accumulation in hoppers and simplifies installations.
Franklin Miller Inc., Livingston, NJ 973-535-9200 www.franklinmiller.com

Aerator/Lump Breaker
The Tuffer aerator/lump breaker effectively reduces moist, semimoist, or dry solids down to near grain size. The fast-moving breaker bars help to reduce lumps with ease and aerate the material. The result is a more consistent particle size and a fluffier bulk solid. Material will gravity feed and flow easier, improving overall handling efficiency. The unit consists of an independently driven shaft powered by a v-belt drive system. The shaft has a number of heavy-duty breaker bars mounted close together to control the particle size desired. This simple free-wheeling design eliminates high-friction forces, thereby lowering horsepower requirements and the need for complex parts and synchronization. The Tuffer is available in various sizes and capacities to suit most process requirements. The low-profile design permits installation in new and existing systems.
Dynamic Air Inc., St. Paul, MN 651-484-2900 www.dynamicair.com/products/aerators.html

Screen Classifying Cutter
The SCC-15 screen classifying cutter cuts hard, soft, and fibrous materials into controlled particle sizes from granules down to 20–30 mesh with minimal fines, and at rates up to 500 cu ft/hr. The patented helical rotor design with dozens of cutter heads attached to a helical array of staggered holders called “interconnected parallelograms” continuously shear oversized materials against twin, stationary bed knives. Carbide-tipped cutter heads along the entire shaft, with no frontal gaps between the tips, cut the product into uniform pieces with minimum fines and imperfections in the granulate, with little to no heat generation. The cutter has a 15-in. throat width and can be fitted with 30 parallelograms with 60 cutter inserts.
Munson Machinery Company, Inc., Utica, NY 800-944-6644 www.munsonmachinery.com

Jet Mill
The Open Manifold Design (OMD) Micronizer offers a solution to herbicide, pesticide, and insecticide manufacturers requiring flexibility for the size reduction of multiple products. The OMD eliminates any hidden areas and allows the mill to be completely disassembled for cleaning. Having access to all internal areas allows the user to switch products without the risk of contamination and reduces turnaround time between the different powders. The unit can typically produce particle size distributions between 1 and 20 µm. The unit employs compressed air or gas to produce particles less than 1 µm. Precisely aligned jets create a vortex. Material is fed into this vortex along an engineered tangent circle and accelerates. High-speed rotation subjects material to particle-on-particle impact,
creating increasingly smaller fines. While centrifugal force drives large particles toward the perimeter, fine particles move toward the center where they exit through the vortex finder.
Sturtevant Inc., Hanover, MA 781-829-1433 www.sturtevantinc.com

Hammer Mill
Available in either carbon or stainless steel, the WA series is a ruggedly constructed gravity discharge hammer mill. Available in more than 20 sizes from 6 to 60 in. with rotor diameters from 9 to 40 in., the unit features replaceable, abrasion-resistant wear plates designed for processing a wide range of hard and highly abrasive materials. Options include custom feed and discharge chutes to accommodate feeding and collecting. Multiple hammer sizes and styles, along with interchangeable heavy-duty bar grates or perforated screens, allow for customization of mill design for each application.
Schutte-Buffalo Hammermill LLC, Buffalo, NY 800-447-4634 www.hammermills.com

Crushers, Grinders, and Shredders
This company manufactures crushers, grinders and shredders for raw-material processing, recycling, and reduction of waste bulk in order to decrease disposal costs. These single-rotor machines include ram-fed vertical models with dump- and-run hoppers and continuously fed horizontal models with vibratory infeed conveyors. Consistently sized output particles are delivered through screens incorporated into the machine. These heavy-duty industrial screens can be quickly and easily changed, allowing the user to determine and change particle size based on application.
Vecoplan, High Point, NC 336-861-6070 www.vecoplan.com

Direct-Drive Disintegrators
Rietz RP series direct-drive disintegrators can be used in most chemical, pharmaceutical, and sanitary USDA/FDA chopping operations. Removing a single band clamp allows fast and easy
access to all critical components for cleaning, inspection, and screen changes. The overhead rotor design keeps bearings out of the product-contact area. A combination of screens, hammers, inlets, and discharges lets the user perform a variety of tasks with a single machine. Adding an ACVF controller provides even more versatility. Models from 3 to 125 hp are available. Tip speeds up to 115 m/sec are possible. Inlet nozzles allow introduction of steam, water, flavorings, reagents, and other additives.
Bepex International, Minneapolis, MN 612-627-1415 www.bepex.com/rietz.htm

Batch-Type Attritor
By purchasing just one frame, tank, motor, gear reducer, and drive, the user can enjoy the flexibility of grinding either wet or dry with this batch-type attritor. The only changeover required involves the shaft/arm assembly, the bottom discharge, and in some cases, the cover. When operating as a wet grinding mill, the S-50 can handle a broad range of applications from ceramics and carbides to inks and chocolate. When operating as a dry grinding mill, the SD-50 (the “D” designates dry grinding) can be used in applications ranging from metal powders to mechanical alloying, pigments, glass frits, and minerals. Because dry grinding requires more horsepower, the mill is built with a larger motor.
Union Process Inc., Akron, OH 330-929-3333 www.unionprocess.com