Getting the right aggregate blend

Infinite control of blending of aggregates for conveying to two on-site asphalt plants is the claim for the fully automated bulk loading system located at Tilcon’s Cairney Hill Quarry. It was designed and installed by Checkmark.

Blending is achieved by means of a series of 16 belt feeders, each one being controlled by a vector drive.

From six vertical bins where lorries are able to load with aggregate, two collecting conveyors extend to feed aggregate blends to the site’s standalone asphalt plants. The aggregates are loaded onto the conveyors via 16 Checkmark belt feeders, all of which are controlled by 3kW Siemens Micromaster vector drives, set in panels, all supplied by BSL Engineering.

The drives are contained, eight to a panel, together with Siemens low voltage switchgear, in control enclosures. A PLC system interfaces to the Siemens drives and downloads speed and operating parameters, which relate directly to the size, and percentage of each size of stone in a blend. Effective and flexible, the system can load the asphalt plant at 150ton/hr, and enables an infinite number of blends to be provided, each with its own Tilcon product code.

BSL Engineering Tel: 01902 422322