Cement Americas provides comprehensive coverage of the North and South American cement markets from raw material extraction to delivery and tranportation to end user.
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www.cementamericas.com • Winter 2017 • CEMENT AMERICAS 39 Martin Engineering in- troduced a more effec- tive return belt track- ing system that uses high-quality materials for easier maintenance and a longer unit life. Building upon the stan- dard crowned roller, the Martin Roller Tracker uses a unique ribbed lagging made of durable polyurethane to increase per- formance and wear life. The roller does not come in contact with the belt edge, which means no fraying and excellent tracking for single-direction or reversing belts. The result is more centered cargo loading, less spillage and increased safety from the hazards of belt wander, leading to higher pro- ductivity and a lower cost of operation. "Crowned tracking rollers have been around for a while, but we saw design issues that prevented them from reaching their full potential," said Rudolf Beer, engineering and de- velopment manager at Martin Engineering. "After creating a working prototype of the new design and testing it at our Center for Innovation, we discovered that we had truly im- proved upon the technology and engineered the best tracker of its kind on the market." Used for lower tension belts from 20 to 60 in. in width, run- ning up to 984 fpm, crowned roller trackers have a slightly larger diameter at the center than at the edges. Realignment is based on the basic principle of the belt contacting the raised portion of the raised portion of the roller first (the crown). When the belt wanders off-center, the assembly tilts to the opposing side and steers it back toward the normal posi- tion. By retaining a consistent path on the return side, the belt passes over the tail pulley and enters the loading zone centered, delivering equal cargo distribution and reducing spillage. Previous designs had lagging made out of a single smooth piece of rubber or soft gripping material, to retain a hold on the belt and train it back into position. Being in constant con- tact across the entire surface of the belt caused the material to wear quickly, requiring frequent and expensive replace- ment. The Martin Roller Tracker improves upon this technolo- gy with ribbed lagging made from thick, rugged polyurethane. Covering the entire belt width using less surface contact, the ribbed design reduces lagging wear and improves resistance to better train the belt back to center. This design is also very cost-effective to manufacture, contributing to a reduced purchase price. With fewer working components than its counterparts and no contact with the belt edge, the Martin Roller Tracker also has a smaller diameter of 7.5 in. – similar in size to other rollers – allowing it to react quickly to fluctuations in the belt path. Built on a central pivot attached to a stiff, vibration-free man- drel, the unit is lifted 0.2 in. under the belt to retain a tight grip on the surface. As the belt drifts, the roller constantly tilts and turns, reacting to the direction of the belt's drift. Engineered with heavy-duty, permanently-lubricated sealed bearings, the Roller Tracker's internal mechanism features an Flexicon introduced a new weigh hopper with a fill/pass valve for dilute-phase pneu- matic conveying systems. Suspended from three small- scale load cells, the gain- in-weight hopper delivers higher accuracy than loss- of-weight systems requiring higher-capacity load cells. Single or multiple hoppers can be positioned along a com- mon vacuum or positive pressure pneumatic conveying line for discharging of dry bulk solids into single or multiple pro- cess equipment, storage vessels or downstream use points by weight. Downstream of the last fill/pass valve, the conveying line can be routed to the original material source point or into a dust collection device. The system's controller weighs a batch by changing the po- sition of the valve, which diverts conveyed material into the hopper. As the hopper fills, load cells transmit weight gain in- formation to a PLC. Once the batch weight has been reached, the valve redirects material away from the hopper. The con- troller then actuates a slide gate valve to open, discharging the weighed batch. Rated for the pressure differentials associated with pneumat- ic conveying, the conical hopper is eccentric with a vertical sidewall to promote complete discharge of weighed materials for batching accuracy. The unit is constructed of stainless steel finished to industrial or sanitary standards to suit virtually any chemical, miner- al, plastics or food processing application. The company also supplies flex-tube diverters, wye-diverters, plug diverters and other line diverter configurations to optimize any pneumatic conveying system. Flexicon Corp., www.flexicon.com Pneumatic Weigh Hopper with Fill/Pass Valve Conveyor Belt Tracker Technology PRODUCTS