Rock Products

APR 2017

Rock Products is the aggregates industry's leading source for market analysis and technology solutions, delivering critical content focusing on aggregates-processing equipment; operational efficiencies; management best practices; comprehensive market

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Page 47 of 67

46 • ROCK products • April 2017 EQUIPMENT & TECHNOLOGY SCREENING & SIZING To effectively recover coarse particles, the Eriez Flotation Division has com- bined the advantages of traditional teeter-bed separators with the selec- tivity of flotation cells to develop a new separation device, the HydroFloat Separator. The primary benefit is the flotation of very coarse material (up to 6 mm or 0.23 in.) that is otherwise lost using conventional methods. The HydroFloat Separator is both a flo- tation device and a density separator, combining the advantages of froth flo- tation and gravity separation. With this technology, the HydroFloat enhances coarse particle recovery, produces higher throughout capacity and reduces reagents and air consumption. The theory of operation is based on flota- tion fundamentals. Fluidization (teeter) water is supplied through a network of pipes that extends across the bottom of the cross-sectional area of the separation chamber. The teeter bed is constantly aerated by injecting compressed air and a small amount of frothing agent into the fluidization water. As the air bubble dispersion rises through the teeter bed, the bubbles become attached to the hydrophobic particles, reducing their effective den- sity and increasing their buoyancy. The lighter bubble particle aggregates rise to the top of the teeter bed and overflow the top of the separation chamber. Hydrophilic particles that do not attach to the air bubbles continue to move down through the teeter bed and even- tually settle into the dewatering cone. These particles are discharged as a high-solids stream through a control valve at the bottom of the separator. Eriez Flotation Division, efd.eriez. com/Products/Index/Hydrofloat Polydeck Debuts Revolutionary Kwikdeck System Either single- or double-crowned decks are the standard for producers using wire cloth on their vibrating screens. Although wire cloth has a low up-front cost, it typically wears out quickly and presents safety and maintenance issues that result in a higher cost over the life of the media. But producers have been hesitant to try the more cost-effec- tive modular synthetic media option because it would require laborious and potentially costly frame modifications. And what if they are not satisfied with the performance of the modular synthetic option? They would need to reverse the installation process, resulting in more cost and loss of pro- duction when reinstalling their crowned deck frame. As a solution, Polydeck developed Kwikdeck, a revolutionary patent-pending system that enables producers to quickly and easily convert a single- or double-crowned deck to modular rubber screen media with absolutely no frame modifications. The entire installation process for each 4-ft. section takes about 45 minutes and utilizes existing bucker bars and side retention rails. Since the modular screen panels contain no latitudinal steel insert, for non-standard deck widths, the panels can be cut to fit on-site. The Kwikdeck system gives producers who currently use wire cloth an opportunity to try modular synthetic screen media with absolutely no risk if they are not pleased with its per- formance. The Kwikdeck system can be removed, the bucker bar rubber and wire cloth reinstalled and the deck is back to its original condition. Polydeck noted that some producers will appreciate the versatility the Kwikdeck system will give them by providing a longer wearing screening option on an as-needed basis. Polydeck, Eriez HydroFloat Separator Recovers Coarse Particles

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