April 1, 2010
By selecting the correct screen media for the application, the best results and value can be realized.
By Carol Wasson
There is more to media specification than meets the eye. Some operators may question why they are asked to provide a mountain of data during the specification process. Quite simply, it’s because proper media specification requires an analytical approach versus pulling products from a mere “bag of tricks.” The right specification strategies upfront allow cost-efficient screen media management over the long term.
“To specify the right solutions, we look at the entire operation from crushing to stockpiling — and we look at the screening circuit as a whole, not just the media,” says Ryan Senter, regional sales manager for Polydeck Screen Corp. He stresses the importance of talking with the entire team at the plant, from the manager to the operator and on to the quality control and maintenance personnel, as each has a specific perspective on their challenges and goals regarding the desired gradations.
At the screening circuit, Senter begins by examining the current equipment when empty or when operating at full tilt. Where are the wear points? Is the screen being fed properly? He looks at issues such as bed depth and carryover, and data is gathered on desired gradations and tons per hour, feed drop distance, and on material type, topsize, weight, shape, moisture content, and more.
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Next, complete information can be compiled on a data sheet and sent to an applications engineer at the manufacturer for analysis. For example, Senter works with Craig Burke, a senior applications engineer at his company and a former assistant plant manager for one of the largest aggregate conglomerates in the nation. Burke says that gradation and wear life are typical hot buttons for the customer. Common questions, he notes, include the following: Will I be in-spec at startup? How long will it be before I must buy new panels?
From a wear life standpoint, Burke recommends that customers provide information on an “acceptable range” of gradation specifications and not just a single target number. He explains that the understanding of a range may allow starting out as tightly as possible