Silos for Abrasive Chemicals Equipped with Wear-Resistant Elbows

MONONGAHELA, PA — Chemco Systems designs and manufactures bulk storage and feeding systems that handle powdered activated carbon, pebble and hydrated lime, sodium carbonate, fly ash, potassium permanganate and other bulk chemicals used for air and water treatment. Chemco’s fabrication facility spans 120,000 sq ft (11,150 m2) and can produce silos 8 to 38 ft (2.4 to 12 m) in diameter. The company designs and builds 30-40 systems annually, engineered for efficient performance by application.

Each component is evaluated, including the elbows that Chemco uses in pneumatic conveying pipelines. "All the materials our clients work with are abrasive and, over time, any type of elbow will degrade if it isn’t specifically designed to handle them,” says Marcus Bollman, project engineer. "For us, the two options are the HammerTek deflection elbow or our own wear-back elbow."

Chemco’s own elbow is a standard rolled 90-degree pipe with rolled steel welded to the back. The Smart Elbow® deflection elbow from HammerTek has a bulb-like protrusion where a loose ball of material rotates in the same direction as the airstream, gently deflecting material around the bend. Material comprising the ball gradually self-renews as it continuously filters out of the chamber as new material enters. Abrasives are prevented from impacting and wearing the elbow wall, eliminating elbow blow-outs.

Long-term wear resistance is critical, Bollman says, because once the elbows are installed, they can be difficult to access. "It’s worth spending a little extra for the Smart Elbow" he said. "I’d rather (our clients) pay more up front than spend additional time and money to replace a normal 90-degree elbow. Plus, the downtime and the cost of a new elbow add up."

Especially when space is tight — commonly at the roof of indoor silos where a vertical transition is needed — the deflection elbows, with a radius of just 10.6 in. (270 mm), are the answer. "When there’s not enough room for a long-radius bend, the elbow's compact geometry enables us to put in the piping very efficiently," Bollman says. "We can bolt it in a tight space and we know it isn’t going to wear."

"The engineers I’ve dealt with are aware of what the elbow is and they trust it," Bollman says. "Some prefer we install that rather than other 90-degree piping elbows." The Smart Elbow product is also easy to source on short notice. "If we have a job to pipe over rather quickly, it is a very good, dependable solution."

He says, "We have systems dating back 20 years with these, and I’ve never heard of one failing."

Chemco Systems
+1 724-258-7333

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Chemco’s silo doses abrasive hydrated lime into a West Virginia stream affected by acid mine drainage. The Smart Elbow® short radius elbow precludes blowouts and replacements of conventional sweep elbows.

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A spherical vortex chamber protruding from the deflection elbow causes a loose ball of material to rotate in the same direction as the airstream that powers it, gently deflecting particles around the bend without impacting or wearing the elbow wall.