Case Study: Rohrer's Quarry

Rohrer's Quarry, Inc. was founded over a century ago in the middle of one of the largest limestone deposits in Pennsylvania, producing agricultural lime for surrounding farms. Midway through the 20th century, a ready-mix concrete plant was erected, and today, Rohrer's Quarry delivers ready-mix concrete to customers in surrounding Lancaster County, Pa. using a 20-truck fleet of spotlessly clean transit mixers.

Several years ago, the Rohrer family recognized the need for a central mix plant to meet customer demand for specialized mixes and all-season consistency. The decision was made to specify a horizontal reversing mixer, which at first seemed to narrow the choice to one of two Canadian-built mixers.

However, when they contacted Jay Robinson of Mid Atlantic Concrete Equipment, the Rohrers learned of CON-E-CO's plans for the first U.S.-built horizontal reversing mixer. Jay helped them sift through their options and specify the appropriate CON-E-CO plant to go with the CON-E-CO HRM-12 mixer.

Erection began in January 2008, and startup occurred in early July, making Rohrer's Quarry the first company to have an HRM-12 mixer in regular operation. The new plant is a CON-E-CO SLP-GS-HRM with three 200-ton cement silos and 340 tons of aggregate capacity divided into six equal compartments. It is fed by a 430-foot vertical curve conveyor from six 12' x 15' receiving hoppers set into a below-grade concrete bunker. At the top of the long conveyor, aggregate makes a 110-degree turn onto a shorter conveyor, which dumps into a turnhead over the aggregate bin.

Batch control is handled by a Command Alkon Command Batch system. Two 15,000 gallon Infern-O-Therm tanks fed by clean-burn waste oil heaters supply process water year round.

To manage a project of this size, Mid Atlantic brought in partner Horst Construction, which constructed a building to enclose the plant. The finished building will provide essential protection from the elements for Rohrer's year-round operation, while containing noise and dust.

Rohrers Quarry Project Photos