Before installing the ES303™ screen from Metso, the company had experienced declining reliability and costly, time-consuming downtime to replace screening media on its old vibrating equipment. The new Metso ES303 screen, in operation since early 2015, is operating smoothly, and helping to boost production and efficiency at the plant.
The Woodlands Plant is located in Conroe, Texas, approximately 40 miles north of Houston. It is owned and operated by Lehigh Hanson, Inc., one of North America’s leading aggregates producers. Lehigh Hanson operates more than 200 aggregates plants in the USA, and its parent company, HeidelbergCement, is the largest aggregates producer worldwide.
A new solution for screening
The Woodlands Plant is situated on the West Fork of the San Jacinto River where, according to Plant Manager Jay Jackson, an electric dredge is used to mine natural sand and gravel. Material is pumped from the dredge to the plant through a pipeline, where it enters a velocity box, or tank, which separates the gravel from the sand. The sand is then pumped in below the screen, while the clay and gravel are processed through the screen.
“The gravel goes across the Metso screen,” says Jackson,” and that’s what we’re using the Metso screen for – the natural washed gravel.” The ES303 uses urethane screening media on all three decks. The top deck screens the clay; the middle deck is used for mid-size gravel, and the bottom deck is for the extra fine gravel that drops through the bottom of the screen. The ES303 also features three water spray bars on it to spray the gravel, and remove the clay.
The choice of the Metso ES303 vibrating screen came as Lehigh Hanson identified a need to modernize their production capabilities at the Woodlands Plant, requiring an efficient screen that was capable of both producing gravel to their specifications, and reducing maintenance and downtime. The new vibrating screen would replace their existing 6x20 incline screen, which had reached the end of its useful life. In addition, the process of replacing the screening media on the old screen was labor-intensive and time consuming.
As part of a thorough review of vibrating screen brands on the market, Lehigh Hanson contacted Crisp Industries, Inc., Metso’s crushing and screening distributor in the state of Texas. Crisp Industries promoted the new ES303 screen to Lehigh Hanson. This new design for horizontal screens does not rely on shafts timed with gears to create an elliptical motion, and therefore has fewer parts to contend with. In addition, when a bearing change is required, the quick change out for Metso’s MV (Modular Vibrator) mechanism requires less downtime than a traditional horizontal screen. Lehigh Hanson felt these were important benefits for their operation. Greg Venghaus, Territory Salesman at Crisp, assessed the existing situation at the Woodlands Plant and suggested replacing the old incline screen with the ES303 “They liked the new technology,” says Venghaus, “and were willing to be the first to adopt it.”