Feed and Flow

1 US Agg June 16
At U.S. Aggregates, a New Electromechanical Feeder Boosts Consistent, High-Quality Product Output.

U.S. Aggregates maintains 17 strategically-located processing sites throughout Indiana. Its marketing mission is tagged as “serving you where you are.” Each facility features “quarry-based teams” that closely focus on a 25-mile market radius, building relationships and providing high-quality aggregate products to local customers.

Installed within the surge tunnel, the Deister feeder delivers consistent material feed and uniform product flow to the wash plant.

The company’s Ridgeville, Ind., plant is one of its oldest limestone operations. Reserves have been mined there since the 1930s; and U.S. Aggregates acquired the site in the late 1960s. The Ridgeville plant processes both concrete and asphalt aggregates, with much of its product feeding an onsite 250-tph asphalt plant.

“Especially with an asphalt plant, material segregation is the enemy. We need to maintain a quality material mix, so that we can maintain a consistent, high-quality finished product,” said Plant Manager Paul Miller. Previously, the operation ran two older feeders in its surge tunnel. “Our challenge was that we were mainly pulling material out of the center of the surge pile. That gave us a lot of variance in our gradations – anywhere from coarse to fine depending upon the level of the surge pile,” said Miller. “We were getting surges of coarse material, then surges of fine material.”

To boost processing efficiencies, the facility replaced its older feeder in the front position with a new two-mass electromechanical vibrating feeder (a 30- x 84-in. EMF 307), manufactured by Deister Machine Co.

“The unit’s heavy-duty spring isolation assemblies allow for suspension mounting, which gives us more flexibility. The feeder has more room to move, so material doesn’t bind up on it. In the long run, that saves on wear and tear, and prevents stress on the frame of the feeder. It’s a far more forgiving setup – and it’s really picking up the slack for us, as the older feeder behind it cannot give us the product uniformity that we need,” said Miller.

Optimum Feed and Flow

“The EMF feeder is designed and engineered to provide greater control over high-capacity feed rates and productivity, while lowering costs per ton,” said Carla Phelps, product manager for the Deister EMF Series.

2 US Agg June 16

The feeder’s heavy-duty spring isolation assemblies allow for suspension mounting, giving the operation more flexibility.
The location of the feeder allows the operation to pull more material off the side of the surge pile to avoid a variance in gradations.

She explained that the feeder’s two-mass technology allows higher feed rates; reduced horsepower requirements; and an ability to easily adapt and adjust to changes in loads. “Operations also want greater reliability and ease of maintenance, so we’ve designed this unit with a machine weight that’s more robust; and a heavy-duty formed deck that features replaceable liners,” she said.

The EMF Series feeder utilizes a simplified drive that’s designed with an easy-access exciter frame, which houses the single vibrator motor. “This results in higher bearing life, and eliminates the need to replace belts. Additionally, we’ve included energy-efficient, pre-compressed steel transmission springs, which are not susceptible to temperature or shelf life,” said Phelps.

Processing Efficiency

Feeders in the surge tunnel at the Ridgeville Plant feed the wash plant only. From the tunnel, material is conveyed to a Deister dry screen. Aglime products are pulled off. Next, any oversize is fed to a cone crusher before being recirculated to the dry screen.

Material passing through is sized and fed to a Deister wash screen before being conveyed to various product stockpiles. “Most of our washed material goes to the asphalt plant. We sell a lot of #8s as concrete aggregate; and area farmers purchase our washed material for a drainage product,” said Miller.

The Ridgeville plant processes both concrete and asphalt
aggregates, with much of its product feeding an onsite
250-tph asphalt plant

As to the installation of the new feeder, Miller stresses that setup time was minimal. “Once we were up and running, we knew that we would save substantial maintenance time, especially where the wear liners are concerned,” he said. “Unlike the older feeder, the wear liners on the feed pan of the new feeder are bolt-in, so they are easy to replace. You simply unbolt the worn liners and bolt-in the replacements, instead of actually having to cut the liners out. Also, this feeder runs a lot smoother than others we’ve had; and you don’t have replacement belts and the greasing.”

Miller said that the EMF Series feeder is delivering the consistent, high-quality product output that the operation requires. “We haven’t had any bugs with it at all; and I think that’s part of the Deister name. Their equipment is good to go right out of the gate, and that’s the way this feeder has been,” he said.

Carol Wasson is a Fort-Wayne, Ind.-based freelancer.