Energy-efficient Aggredry® Dewatering Washer delivers sustainable sand washing solutions
With water conservation and cost-effective sand washing and fines recovery as its mission, U.S.-based Superior Industries has recently introduced its patented and field-proven Aggredry® Dewatering Washer to the global marketplace. Engineered for sustainability, this energy-efficient sand washing solution combines a fine material washer and a dewatering screen in a single machine. Its innovative design ensures significant reductions in water use and horsepower requirements, and a higher volume of saleable product at lower costs per tonne.
Energy-efficient alternative to cyclone
The “The Aggredry dewatering washer offers an energy-efficient alternative to the excessive horsepower requirements of cyclone plants, while allowing producers to effectively wash and dry the material, achieving precise sand specifications with a moisture content as low as 8-percent,” says John Bennington, a wet processing technology expert who serves as director of washing and classifying equipment for Superior Industries.
“While cyclones are commonly used in sand washing applications throughout Europe, the slurry pumps in cyclone plants significantly increase horsepower requirements and inflate energy costs,” he says.
“Using as little as one-third to one-half the horsepower per metric ton as that of the typical cyclone plant, the Aggredry dewatering washer delivers considerable energy cost savings, while producing a high-quality finished product that requires no drying time and is immediately saleable,” stresses Bennington.
Water-wise operation
Bennington notes that the Aggredry washer is engineered to minimize water usage while capturing, re-circulating and re-using valuable water resources within the system. This allows operations to cut water usage by 50-percent or more, when compared to conventional methods.
Bottom line, Bennington says that the Aggredry is designed to overcome all the disadvantages of wet processing – water and material waste; stockpiling space for drying time; and costly pond maintenance.
Within the Aggredry system, the fine material washer removes clay, dirt, and crusher dust from the sand. The dusty water is washed out the backside, while the saleable material is discharged to the integrated dewatering screen, where the remaining water is separated and captured for re-use. The result is finished saleable material with a moisture content ranging from 8- to 10-percent.
For optimum fines management at the wash circuit, the Aggredry washer features a fines recovery system where minus-.03 mm material fines collect in an under flume and are re-introduced back into the material washer via a water jet. “This patented technology saves at least 3-percent of that material for a saleable product and prevents unnecessary material waste going to a settling pond,” says Bennington. He stresses that this material savings really adds up, as at 100-metric-tons-per-hour production, material savings adds up to three-metric-tons-per-hour – or a full truckload of saleable material per each shift.
“The unique factor of the Aggredry is that it does not allow the material particles that go through the dewatering screen to be lost. Instead we use a simple device to eject the water and through particles back into the sand screw,” says Bennington.
Field-proven performance
In recent years, the Aggredry dewatering washer has become a popular choice in the U.S. for companies such as Milwaukee, Wisc.-based Wissota Sand & Gravel, an operation that’s realizing all the advantages of effective sand washing technology at a fraction of the typical costs per ton in its specific application.
When using their prior sand screws, the material was coming out at about 25-percent moisture content, causing material to stick to conveyor components, or slough off into the wheels of the radial stacker. Also, they had calculated a water loss of about 400-gallons per minute, with the water going to a part of the operation where it could not be recovered. Rather than locating some surface water that could be recovered; or pumping water from a deep well, Wissota decided to install the new Aggredry system.
The Aggredry system at Wissota features twin fine material washers combined with twin high frequency dewatering screens. Sand is coming off the two screens at 8-percent moisture content, requires no drying time, and is immediately saleable. The dry material is easy to convey even when the stacker is elevated to its full height, allowing the operation to manage its stockpiling far more effectively. Most importantly, they are realizing a water savings of about 350-gallons per minute. Additionally, if they hit a dirty spot in the pit, the Aggredry allows them to process the dirtier material and still manage the fines on the wash end of the plant, giving them more throughput without having to be so particular about the material coming from the primary circuit.
According to the Wissota management team, their attraction to the Aggredry stemmed from “its unique combination of two ‘tried-and-true’ technologies – sand screws and high frequency dewatering screens.”
Bennington explains that a traditional sand screw is a perfectly adequate technology on its own, but it does require additional real estate for drying time, as well as a plan for handling the water runoff. “The option of running a straight dewatering screen is also adequate,” he says, “but you will lose up to 4-percent of your finished material. In the end, either a screw or a dewatering screen can operate as a stand-alone, with some drawbacks; however, the innovative blend of both technologies positions the Aggredry as the standard washing solution for sand and gravel,” says Bennington.
Rock Face to Load Out® sustainability
Superior Industries designs, manufactures, and supports sustainable material processing solutions from rock face to load out - from feeding, crushing and screening, to washing, conveying, stockpiling, and loading. “Versus those manufacturers who rely upon outsourcing various plant components, Superior Industries manufactures equipment for every function of material processing, and this ensures the highest level of quality control,” says John Garrison, vice president of sales for Superior Industries.
“While some manufacturers merely launch a product, Superior is dedicated to supporting that product from within the local market,” says Garrison. “We’ve built successful distributor relationships worldwide, and we are developing additional dealer partners in Europe, the Middle East and Africa,” he says.
“Importantly, as a single-source provider, Superior is better able to package and customize solutions to meet each specific application, while helping producers gain greater sustainability.”