Aggregate Environmental Control Systems
From reducing dust to cleaner water, here’s a guide to what can help keep your operation environmentally friendly.
by Tina Grady Barbaccia, Senior Editor
Gravitational, inertial forces
The Mobile Classifier from Buell is composed of the Buell GI-108 Gravitational Inertial Classifier, two cyclones, a filter, fan, air compressor, two discharge conveyors, and a control panel with starters, all of which are situated on a single, flatbed trailer. The system is equipped with hydraulics that allow the system to be set up in about two hours. Ceramic liners are included in certain areas to provide wear protection when processing abrasive materials. The classifier has a 75 tons-per-hour feed rate and combines gravitational, inertial, centrifugal, and aerodynamic forces to efficiently classify materials at cut points ranging from 50 to 200 mesh (300 to 75 microns).
Uses half the horsepower
The Aggre-Dry FMW (fine material washer) Screen from GreyStone washes and dewaters aggregate material, combining a fine material screw and dewatering screen that the company says produces sand and gravel with a moisture content as low as 8 to 13 percent, by weight, while using less than half the horsepower required to process the same tonnage of spec product using a traditional screen/cyclone system. The dewatering screen features a 0.25-mm screen that reduces the amount of material that can fall through the screen. The feed from the screw allows the material to build to a bed depth of 14 inches on the screen, squeezing additional moisture from the sand as the vibratory motors move it along the length of the screen cloth, further reducing moisture content.
Monitors thickener bed level
Autofloc controllers from Nalco function as feedback or feed-forward controllers used to monitor and control clarification/thickening operations. The company offers a variety of controller types ranging from one that monitors the thickener bed level and adjusts flocculant dosage accordingly to another that monitors water clarity in ponds and thickeners. The company also offers a third controller that measures floc size in thickener center wells and adjusts polymer dosage.
Reduces particulate matter 99.9 percent
Huss LLC showcased its Diesel Particle Filters (DPFs) during March’s ConExpo-Con/Agg tradeshow in Las Vegas. The DPFs have been independently proven to reduce 99.9 percent particulate matter (PM), according to the manufacturer. The company offers filter systems with a broad range of regeneration strategies, providing solutions for both retrofit and OEM to help clean diesel exhaust. The MD-System, a diesel particle filter with active diesel injection, combines active and passive DPFs and allows continuous regeneration.
The new wall flow filter is made of liquid-phase sintered silicon carbide (SiC) with 200 cells per square inch density, high mechanical and thermal durability, and high chemical resistance. The filter is made to resist corrosive residues in the fuel and extreme differences in exhaust gas temperatures during operation and while regenerating. It also withstands severe crushes due to uneven terrain. The specially designed triangle channel structure offers nearly 15 percent more filter area compared to the traditional quad.
Innovative Equipment Solutions
Fully automated, drive-through system
Innovative Equipment Solutions (IES) introduces it new Neptune Series of fully automated, drive-through wheel wash systems, which can be configured with one-, two-, or three-tire revolutions of cleaning to eliminate jobsite trackout. Featuring concrete- or galvanized-steel sidewall construction, the Neptune system works in both permanent and temporary installations. All models are engineered with a fully automated, closed-loop water recycling and solids separation process so that water present at the site entrance does not create any additional issues. The series features a high-volume, low-pressure water design, which prevents overspray and the knocking of oil and grease from the truck chassis. Its extra-wide, 42-inch wash elements flex the tire tread open to allow the high water volume flow to flush the tires clean. Adjustable nozzle assemblies allow for a highly focused spray.
Each system is configured with the appropriately sized water recycling and solid separation tank. A self-priming flocculent pump increases the cleanliness of the recycled water. Solids can be removed with equipment that would typically be on-hand at a site. Pumps are installed using autocouplers that allow the operator to remove the pumps from the tank without the need to dewater the tank, which is a significant savings in time and water during any maintenance or repair.
IES also offers its new portable aboveground Maximus Series, which also offers a fully automated, closed-loop water recycling and solids separation solution.